Solplan Review No 156

6.3 MB·English

by  Richard Kadulski

\a
No. 1^0 ■ ■ 0 January 2011
/©Iplan review
I
the independent journal of energy conservation, building science & construction practice
inside . . .
Net Zero Housing...................................................3 Technical Reearch Committee News.................12
Value Index calculation........................................4 Online Building Science Research; Profes­
Energy Conservation Measures For NZEH........4 sional Builders’ Institute; 2010 National
NZEH Design Principles: Current Building Code Changes; Cross-Canada
State-Of-The-Art.............................................7 Radon Survey
Air-Source Heat Pump For Hot Water.................8 Update: Great Canadian Reno Demo v 2.0...........14
You Asked Us: About basement Energy Answers..................................................16
floor insulation.................................................9 Changes to the 2010 NBC for Radon
Basement heat loss.................................................9 Protection in Dwelling Units.........................18
You Asked Us About: Vapour Barriers.................11
Net Zero Housing
2 SOLPLAN REVIEW February 2010 SOLPLAN REVIEW January 2011 3
From the Editor . . . widely used on commercial projects. Most building suppliers Net Zero Housing
in the area, whether they are independents (and there are not
many of those left) or the big national chains did not have the
The last century has seen many technological changes. The
product, or more importantly, either professed not to know The buzz today is about Net Zero Houses. It’s Contrary to popular belief, designing a house that can operate
way we build buildings and the materials we use have changed
about it or were not willing to consider special ordering it. become the holy grail of building, as everyone comfortably and safely without purchased energy is easy at
significantly. Today we have a better understanding of how -
The product in question, polyisocyanurate insulation tries to build more sustainable buildings. In ad­ least from a conceptual perspective - it’s just the details that get
buildings work.
board, although not regularly used in residential construc­ dition, codes authorities in various parts of the a little tricky.
Our expectations have also changed. In the past, lifestyles
tion, has been on the market for many years, is being widely world are indicating that in the not too distant
accommodated variations in the conditions in buildings. People
managed to live without the conveniences we have today and used in commercial construction, and is not an exotic recent future regulatory changes will make it a manda­ systems are added to provide the balance of the
innovation. So it is hard to understand why the retail­ tory requirement. This is seen as a responsible energy requirements.
some still don’t have - not only in the less developed parts of
the world, but within Canada itself. People wore different cloth­ ers were so unprepared for such a request. Not only were target given that buildings account (depending on However, these are largely qualitative guide­
ing in winter than in summer, dealing with poorly insulated and the suppliers not willing or able to access a special order style, occupancy, and location) for about 1/3 of lines with little quantitative detail. They still raise
heated homes. Today we expect to have all the conveniences product, many tried the sales technique of bad-mouthing the all energy consumption, and it is energy con­ issues about what are “massive” amounts of insu­
and be able to run around our homes in shorts, t-shirt and bare product by weaving tales about the product to discourage sumption that is the major contributor to climate lation and just how airtight the house needs to be.
feet year round, regardless of the weather. anyone from pursuing the search. change over which we can have some impact. A recent study by Gary Proskiw (from
With the greater emphasis on energy efficiency, comfort, and This points to a challenge many designers and builders Building a Net Zero Energy House (NZEH) Proskiw Engineering in Winnipeg) and Anil
superior performance expectations, manufacturers are continu­ ave accessing new technologies. For many, even in the big is easy - the challenge is how to do it without Pahrek (from Natural Resources Canada) exam­
ously developing new products and systems to help us build cities, the local building materials supplier is the main con- spending an excessive amount of money. This ines the issue of NZEH design optimization for
better and more efficiently. Many products have been designed on,y for Pr°ducts, but also for product information, requires careful design optimization - how much houses - looking at various Energy Conservation
to make the construction process smoother and easier for the u e it is difficult to expect a sales person in a location that insulation to use in various building enclosure Measures for three representative house types in
builder, while at the same time applying building science les­ as an inventory of several thousand items to know every- components, how much and what type of glaz­ four different climatic zones.
sons learned through trial and error and research. tw u! T 'S t0 ^now ab°ut their inventory, it is important ing to use, what type of mechanical systems to The intent was to put together a set of guide­
Over the years we have highlighted some of these new prod­ ia ey e: aware of their products, how they are used, and use, etc. And perhaps most importantly, know­ lines of the energy-related design features for a
ucts, as well as passed on lessons that research has uncovered. e PrePare jo deal with new products or processes. ing when to stop using conventional energy and NZEH house that can be refined and applied to
Living in the big city, where most of the new products have win 'Sf °U j y di^cu,t for those in smaller communities when to switch to renewable energy sources to actual houses, with their unique architectural de­
been developed and are marketed, we take for granted the avail­ without ready access to mainstream suppliers. As we move supply the balance of energy. tails and geographic location. In addition, a pro­
ability of a wide range of products to meet any requirements hniTfrad! ^U,ldmg Performance, and toward net zero energy Although there are no major technical or cedure was developed that allows one to identify
needed. Given the ‘just-in-time’ distribution for many distribu­ the ! ^cornes esPecially important that everyone in design issues to building Zero Energy houses, it is at what point renewable energy sources should be
tors, there may be only an occasional delay in accessing what­ that r3S Ul* access t0 a broad selection of products unclear how to reach this goal without incurring used in lieu of further conservation upgrades.
ever product is needed. buildings^1 ^ economical construction of efficient significant and (for most consumers) prohibitive Because almost any house can theoreti­
Since many manufacturers and distributors have become na­ costs. One analysis of a proposed Net Zero Energy cally achieve near-NZEH status as long as the
tional behemoth chains, one would assume that products avail­ 3 trfnd t0 more riS°r°us demands for training House for the Prairies found that the incremental occupants are prepared to forgo the comfort,
able in one location would be available in all locations, whether dem „d t °f rriOUS trades- P^aps it’s time that we cost, beyond that required to construct the house health and safety benefits of modern housing,
they are company owned or franchise outlets. Recently it came demand the same of those in the supply industry. to the R-2000 Standard, could be as much as 50 to an implicit caveat of the project was that the oc­
as a surprise to find out that is not the case. 75% of the selling price (exclusive of land). cupants should not have to live “cold, dark and
We were contacted by a subscriber from a small remote com­ Almost all of our understanding about the unwashed”.
munity on Vancouver Island. He was lamenting the hard time energy performance of buildings has been de­
Cost Optimization Of NZEH Houses
he was having getting access to a rigid insulation product that is Richard Kadulski, veloped using conventional and energy efficient
Editor structures, especially houses built to the R-2000 Conservation measures are well understood,
Standard. generally have an established track record of per­
/olplan review PPousbtliacgaeti opnasid M ina iVl Aangcreoeumveern, tB NCo.. 40013363 CHANGE OF ADDRESS: include a mailing label The current state of the art in Net Zero Energy formance, are relatively economic and are, for the
Return undeliverable Canadian addresses to or copy all information off label for faster, accurate House design focuses on minimizing the building most part, durable. They can also be applied to
processing.
Editor-Publisher: Richard Kadulski PO Box 86627, North Vancouver, BC V7L 4L2 CONTRIBUTIONS: Unsolicited contributions and enclosure heat loss by using a simple architec­ virtually any house without major modifications
COPYRIGHT 2010 by The Drawing-Room Graphic
Illustrations: Terry Lyster Services Ltd. All rights reserved. manuscripts welcome. Include self-addressed tural layout, adding massive amounts of insula­ to the design or impact on the occupant’s lifestyle.
Contributors: Rob Dumont, Janet Ansell, Frank Reproduction without written permission of the pre-stamped mailer if return requested. Publisher tion and achieving extremely airtight enclosures. Adding moderate levels of conservation meas­
Lohman, Gary Proskiw, Anil Parehk not responsible for loss or damage of same.
ISSN: 0828-6574 publisher is strictly forbidden. Transgressors who While every effort is made to provide accurate Then the most efficient space heating, water ures tends to initially produce significant savings
don’t take heed note: The shadows will be full of
Date of Issue: February 2011 and complete information, we do not warrant or heating and ventilation systems are installed, at modest incremental cost. However, as the level
surprises - and won't be what you think. A license
SthOe LdPraLwAiNn gR-EroVoImEW gr ias pphuibcl issehrevdic 6e tsim lteds. peryear by: for photocopying or other reprographic copying gsuucahra inntfeoerm tahteio na.ccuracy and completeness of along with energy efficient lighting and appli­ of conservation increases, the rate of further sav­
PO Box 86627, North Vancouver, BC V7L 4L2 can be also be obtained from Access Copyright ADVERTISING POLICY: Publisher’s discretion ances. The designs are adjusted to maximize ings declines and the costs increase. This trend
Tel: [phone] Fax: [phone] (Canadian Copyright Licensing Agency, 1 Yonge in the acceptance of any advertisement. No passive solar gains (but avoid excessive glass continues until a point is reached at which the
St., Suite 800, Toronto, ON M5E 1E5). endorsement is stated or implied by the publisher.
e-mail: [email protected] SUBSCRIPTIONS: In Canada 1 year $56.00 (incl PRINTED IN CANADA areas - typically not greater than about 6% south cost of saving energy using conservation is great­
Street address:
#204 - 1037 West Broadway HST) (NB, NS, NF $56.50 includes HST); 2 years GST Registration: R105208805 facing glass to floor area), and renewable energy er than the cost of producing new energy from
$100.80 (incl HST) (NB, NS, NF$101.13 includes SOLPLAN is a registered trademark of the
Vancouver, BC V6H 1E3 renewables. At this point, the designer should
HST). USA and other foreign payable in US $ 1 Drawing-Room Graphic Services Ltd.
year $57.00, 2 years $103.50.
4 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 5
Vancouver Winnipeg Toronto Yellowknife
Architectural features
direct further energy investments into renewable fined as the process of selecting energy conserva­
energy sources, even though their cost may be tion measures and renewable options based on both Light weight
Thermal mass Light or medium weight framing or heavy masonry
high since they are still less expensive than the their costs and energy performance, so that the framing
competing conservation alternatives. incremental cost of upgrading the house to achieve
Orientation South
Cost optimization of NZEH houses can be de- NZEH performance is as small as possible.
South-facing glass
Proskiw developed the “ Value Index" as a tool 6% of floor area
area
to make it easier to compare options. It provides
Example of Value Index calculation
an incremental cost of energy conservation meas­ Building Enclosure
ures and allows one to compare the cost-effec­
The most common renewable energy source used in NZEH houses is Airtightness 0.50 ac/hr or as tight as possible
tiveness of various Energy Conservation Meas­
photovoltaic. Currently, photovoltaic arrays cost about $7 to $8 per Watt
of rated capacity, while the complete system (which includes the array, ures (ECM) against renewable energy options. Main walls R-30 (RSI 5.28) R-60 (RSI 10.57) R-60 (RSI 10.57) R-60+ (RSI
10.57+)
inverter, controls, wiring and other components) averages approximately ECM Value Index =
$8/W to S10/W. In southern Canadian locations these systems will cur­ (incremental cost of the measure) Attic R-70 (RSI 12.33) R-80 (RSI 14.09) R-80 (RSI 14.09) R-80+ (RSI
14.09+)
rently produce about 1000 to 1200 Wh/yr per Watt of rated capacity. (annual energy savings)
Basement walls R-24 (RSI 4.23) R-24 (RSI 4.23) R-24 (RSI 4.23) R-50 (RSI 8.81)
PV Value Index = PV system cost
Energy Conservation Measures
annual energy production R-10 (RSI 1.76) R-10 (RSI 1.76)
Basement floor Uninsulated Uninsulated
= _$_ For NZEH perimeter perimeter
kWh/yr
Three typical merchant-built houses with full Windows High ER units (see text)
For example, the current average cost for a PV system cost is about
basements and ranging in size from 1200 ft2 to
Mechanical systems
$9/W and it will provide about 1100 Wh/yr per W. If the numbers are put
3000 ft2 houses were modeled using HOT2000.
into the equation, we get the cost to generate 1.0 kWh per year: Initial insulation and airlightness levels, mechan­ Electric baseboards or Ground source Electric
Heating Electric baseboard heat pump (GSHP), COP = 3.0 baseboards or
= 9 S/W ical system details, etc. were typical of levels that
Electric baseboards or GSHP, COP = 3.0 GSHP, COP = 4.0
1100 Wh/yrxW would be used for a NZEH house in four repre­
= $8 per- kWh/yr (Current (2008) PV Value Index) sentative Canadian climate locations: Vancouver, a) Conservation package &
Winnipeg, Toronto and Yellowknife. Domestic hot water b) Grey water heat recovery
c) Thermal solar
In other words, the cost of a installing a PV system capable of producing A variety of ECM’s were analyzed by mod­
d) Domestic hot water heat pump system (possibly)
1.0 KWh/yr would be about $8 (using 2008 prices). Thus, any conservation eling every house/location combination with and
without the measure. Energy savings were calcu­ Ventilation system Ultra high-efficiency HRV
measure that saves 1.0 kW/yr can be economically justified, relative to the
PV option, as long as its cost does not exceed $8. lated and upgrade costs estimated to produce the Base loads 40% of R-2000 defaults or lower
If the conservation measure’s cost is greater than $8, then the PV option Value Indices. This permitted design decisions to
be made based on cost-effectiveness, rather than Cooling system A/C, SEER=18
is more economic. Since the goal of a NZEH house is to consume zero net
energy, the Value Index becomes the only economic tool required. No in­ on historical precedent or an intuitive sense of
what should be done.
formation is required (or needed) on the usual economic variables typically
Using these, a variety of features can be se­ Coefficient - while most other envelope or me­
associated with life-cycle costing such as interest rates, energy escalation The most cost-effective architectural, building
lected and modeled in HOT2000 and the design chanical system measures generally depend on
rates, inflation rates, amortization periods, etc. These factors will determine envelope and mechanical system options were
fine -tuned. This should help expedite the design only one variable, usually the thermal resistance
selected. We summarize the design guidelines
how long it takes the NZEH house to pay back its investment, but have no
process and help arrive at a design that is closer or the mechanical system efficiency.
effect on what measures, or how much of them, should be incorporated into or a medium-sized house in the four climate
to the economic optimum - thus reducing the The Energy Rating (ER) concept was devel­
zones. Each ECM (for insulation levels, types of
the design.
overall cost of the building. oped for windows to address this complexity.
mechanical systems, etc.) was selected to give
Thus, the Value Index has two applications: comparing the cost-effec­
The Value Indices were calculated using a The ER is a single-value number that describes
the lowest energy use while still having a Value
tiveness of competing Energy Conservation Measures and comparing the
costing database created using Winnipeg data ef­ the net energy performance of the window over
Index that was less than the PV Value Index. As
cost-effectiveness of ECM’s against renewal energy options.
fective March 2008. Although the differences in in­ the heating season taking into account the effects
such, each represents the optimum measure for
that component. cremental costs of conservation measures are much of the thermal resistance, Solar Heat Gain Coef­
Advantages Of Using The Energy Conservation Measure and These design guidelines provide a starting less dependent on geographic location than the cost ficient and air leakage.
Value Indices Approach point for the energy-related, design features of new houses, there will be some differences. The study found that the Energy Rating (ER)
including the architectural design features, pre­ number was a valid tool for comparing the ther­
Both have equivalent environmental advantages and disadvantages. Windows
liminary R-values for the major envelope com­ mal performance of windows in NZEH houses,
No knowledge is required of future conditions such as:
- Interest rates ponents and performance characteristics of the Development of guidelines for windows is even though the ER concept had been developed
-Amortization periods mechanical systems needed to achieve NZEH. a more complicated process because window for conventional houses. Basically, the window
- Energy escalation rates. These are summarized in the attached table. performance mainly depends on two variables with the best (highest) ER number had the lowest
- thermal resistance and the Solar Heat Gain energy consumption, although this does not neces­
6 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 7
sarily mean it was the most cost-effective choice. amount of energy. Therefore, provided the utility Basement Walls - Contrary to expectations, drain water heat recovery unit and a thermal solar
A simple method was developed that permit­ will purchase energy> at the same rate as it sells it basement wall upgrades routinely displayed high energy system was recommended. It was also
ted the cost-effectiveness of various window to the house, the net energy’ bill will be zero and Value Indices and hence poor cost-effectiveness. found a self-contained heat pump that extracts
designs to be quickly compared using only their therefore the cost of energy (the utility rates) has In all locations, the most economical basement heat from the indoor air and uses it to preheat
respective costs and ER numbers. Finally, it was no impact on the design or operation of a NZEH. wall insulation scheme was only R-24 (RSI the DHW could be effective. A minimum COP
found that this method could also be used to 4.23). This was due to the beneficial effects of of 1.50 was recommended. This system may
Thermal Mass - The impact of increasing the
compare the cost-effectiveness of window op­ the surrounding soil and the high relative cost of also provide a supplemental benefit of helping to
thermal mass on the overall energy performance
tions to that of the photovoltaic option. exterior insulation used in some of the options. dehumidify the indoor air and thereby improve
was found to be modest, typically producing
Orientation - Perhaps the most interesting Basement Floor Slab - Surprisingly, the comfort during the cooling season.
savings of 100 to 700 kWh/yr, although the
observation regarding house orientation (the benefits of insulating the basement floor slab Space Cooling - Although the cooling load
latter would only be achieved if the house were
direction where the majority of the glazing faces) were not as significant as had been anticipated. in NZEH houses represents a small part of the
upgraded from lightweight framing (which prob­
was that the percentage savings were surprisingly In milder climates the recommended treatment overall energy budget in Canadian locations,
ably describes most new Canadian houses) to
consistent regardless of geographic location. was to leave the slab uninsulated while in colder overheating can cause serious comfort issues. If
very heavy concrete construction. These savings
Changing the home’s orientation from south to climates, such as on the Prairies or in the North, a space cooling system is included in the design,
represent about 1% to 2% of the total, annual en­
southeast or southwest increased total energy a perimeter skirt of R-10 (RSI 1.76) insulation then for most houses a relatively conventional,
ergy consumption of the house and is relatively
consumption only by about 1 % to 2% regard­ was recommended. In part, this could also be a mechanical air-conditioning system is recom­
unaffected by house size.
less of size or location. Significant performance result of current understanding and calculation mended with as high a SEER value as possible.
Airtightness - Improved airtightness was
reductions did not occur until the orientation tools for heat flows below grade. If the house uses a GSHP, then it can be used to
found to be one of the most cost-effective
exceeded 90% off south. This means that energy Space Heating Systems - the optimum space provide the cooling
methods to improve the overall energy efficiency
consumption is not overtly affected by small heating system is very location dependent. In Base Loads - Base loads were one of the most
of NZEH houses, even though the base case
changes in orientation. mild climates, electric baseboard heating was the cost-effective ways of reducing energy use in
scenario used in the analysis assumed an airtight­
South-Facing Glazing Area - Although most cost-effective system identified. In Prairie a NZEH house. Any device or control strategy
ness of 1.50 ac/hr50, the maximum permitted by
increasing the amount of south-facing glazing and Northern climates, either electric baseboards that can reduce the amount of energy being used
the R-2000 Standard.
area is often touted as a practical method for or a Ground Source Heat Pump (GSHP), with a for lighting or appliances, inside or outside the
For example, reducing the leakage to half this
reducing energy use, the analysis found that the minimum rated COP of 4.0 is recommended. In house, should be aggressively explored and con­
value (0.75 ac/hr50) produced savings of over
cost-effectiveness of this practice was very poor Eastern Canadian locations results are similar to sidered for inclusion in the final design - even if
1000 kWhe/yr in six of the 12 house/location
if a high-quality window was used. Basically, the Prairies except the GSHP was only recom­ the costs are quite high. These conclusions were
combinations studied. In fact, a design goal for
the cost of purchasing an additional square foot mended for larger houses. most significant in wanner, rather than more ex­
NZEH houses of 0.50 ac/hr50 was recommended
of south-facing glass was less than the energy Domestic Hot Water Heating - Several of the treme, climates since there is less opportunity for
even though it may be difficult for some build­
savings that would result or which could be pro­ domestic hot water options were cost-effective heat losses from lights and appliances to offset
ers to achieve, at least initially. Not only will an
vided by other conservation measures. This study compared to the photovoltaic option. In all cases, the space-heating load.O
airtight envelope save significant amounts of en­
assumed full solar access. If there is any shading a high-efficiency electric tank coupled with a
ergy but it will improve the structure’s durability
due to adjacent buildings, vegetation or from the
and comfort, reduce the transmission of outdoor
house itself, then the benefits of south-facing
NZEH Design Principles: Current
noise, and provide other benefits. This becomes
glazing would be less. Although only a handful of NZEH houses
more pronounced in colder climates. have been designed or built in Canada, there is State-Of-The-Art
Exterior Walls - The economics of upgrading
Some Additional Findings general agreement about the overall approach
exterior wall systems is heavily dependent on the
and features to be included in the building.
Cost Of Energy - It is commonly believed climate. Relative to the photovoltaic option, the Minimize heat loss through the building enclo­ urban applications, this can include photovol­
that the cost of energy has a direct bearing on the optimum insulation level for milder climates was sure by using a simple architectural layout, high taic (solar electricity) and solar thermal sys­
design of Net Zero Energy Houses, with addi­ about R-30 (RSI 5.28). In colder climates, such levels of insulation and a very airtight enclosure. tems while in rural areas wind power and other
tional conservation or renewable energy sources as the Prairies or far north, the optimum level Select the most efficient space heating, water sources of energy may also be considered.
being justified in areas with very expensive would about R-50 (RSI 8.81). However, the eco­ heating and ventilation systems available. These five design principles are listed based
energy. This is untrue. nomics of wall upgrades must also be compared Use energy efficient lighting and appliances on their relative cost-effectiveness. This is im­
Utility rates (i.e. the cost of purchased en­ to the other conservation alternatives. and minimize exterior energy use, thus reducing portant as it defines for the designer the order in
ergy) have no impact on the design of a Net Zero Attics - Upgrading attic insulation is a surpris­ the base loads as much as possible. which various measures should be implemented.
Energy House, provided one caveat is satisfied. ingly cost-effective measure even though the Maximize passive solar gains by using as Low cost measures that provide significant en­
By definition, the house will produce as much assumed base case attic insulation level was much south-facing glazing as possible while still ergy savings (such as most energy conservation
energy as it consumes. Therefore, while the already high (R-62.5 - RSI 11.01). Value indices maintaining the so-called “6%” rule for glazing options) should be implemented first followed
utility rates will affect the gross energy bill (the for higher insulation levels were less than the PV (limiting the area of south-facing glazing to no by the remaining measures. Renewable energy,
energy purchased from the utility) it will have no Value Index for most of the location/house size more than 6% of the floor area). despite their philosophical purity, should only be
impact on the net energy bill since the house will combinations studied. The only exception was Use renewable sources of energy to provide used after other measures have been exhausted
produce and sell back the utility exactly the same for a small house located in a mild climate. the balance of the energy requirements. For because they are usually expensive sources of
energy relative to conservation alternatives.
8 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 9
Air-Source Heat Pump For Hot Water the use of CO, as a refrigerant, the environmental You Asked Us:
impacts are significantly smaller.
About basement floor insulation
One of the byproducts of transferring the heat
Air-source heat pump water heater sys­
from air is cold dry air. In some commercial ap­
tems use heat extracted from the air to produce
plications, this cold dry air is utilized for cooling
hot water very efficiently. Typical air-source We have a whole house renovation underway in North Vancouver and the client wants in-floor heat­
purposes, further increasing their efficiencies.
heat pumps we see in Canada are the “air-air” The mini-split air source heat pumps are very ing in the basement. Originally, the house was heated by forced warm air.
variety utilizing an outdoor coil/compressor sys­ attractive because they can provide both heating Heating ducts in the basement were in the floor slab. We would like to place the new heat­
tem matched with an indoor coil in an air handler and cooling. When the heat pump is run in re­ ing tubing on the existing slab, and pour a concrete topping on top. However, the building
(furnace). In this configuration, the heat extracted
verse, it effectively becomes a refrigerator. This inspector insists that we need to place insulation under the floor, as per the current BC Build­
from the outdoor air is used to heat air passing
solves a problem for hydronic systems in cooling ing Code requirement that heated floor slabs must be fully insulated with R-12 insulation.
by the heating coils. An alternate, arguably more
seasons. When the outdoor system is coupled
Installing this insulation will entail a lot of cost to raise doors heights, change the staircase,
efficient method to transfer heat is by capturing
with strategically placed indoor cooling units,
move plumbing clean-outs up, etc.
the heat in the air and storing it in water.
performance can rival and exceed that of central
This is the premise for the emerging technology I am not really sold on this insulation in any case (even new construction) as the reasoning
air conditioning systems. Applications of air-
of air-source heat pump hot water appliances. Air is strictly to direct the heat upwards and prevent heating of the soil below. Is heating the soil
water heat pumps are most conducive to in-floor
source heat pumps for hot water have been around mass below really an issue? Is it not actually a benefit as you would have smaller swings in
hydronic heating systems coupled with hot water
for quite a while; however, Canadians have more tanks for domestic hot water. temperature? Doesn’t the existing slab below actually help with the heat sink as well?
readily adopted the indoor combined units. Re­
Studies are currently under way at National
cent advancements in the “min-split” variety (uti­ Resources Canada to qualify the real world per­ The insulation under a heated slab is impor­ is slower below ground the amount of insulation
lizing an outdoor unit and an indoor unit) allow formance of these units in the Canadian climate. tant. The deep ground temperature is always required would not be as much as for building
these appliances to work down to -30°C, making One primary concern in cold climates is that the cooler (although not as extreme as above grade enclosure components above grade.
them more palatable to the Canadian appetite. outdoor units can become frosted, thereby reduc­ - in Vancouver the average deep ground tem­ In your case, you are also dealing with an
The vast majority of the advancements have ing their efficiency. Though appliances typically perature is 11°C). This means that there will interpretation issue. Usually, some leeway needs
come from the Japanese EcoCute, Eco for Ecol­ have built in defrost mechanisms to deal with this always be heat flow outward from the house into to be given when renovating existing houses.
ogy/Economic and Cute from the Japanese word problem, the defrost cycles reduce their efficiency. the ground, albeit not as great as through the Unfortunately, you seem to be caught into an
kyiitd ‘‘supply hot water”. Derived from novel In efforts to mitigate this and artificially increase exterior walls or ceiling above grade. The table application of new construction standards to a
solutions to air conditioners for cars, the Eco- their efficiency, systems can leverage some the (p.10) shows typical deep ground temperatures in renovation. This can be tough because to get
Cute’s utilize natural refrigerant CO, in place of hot air leaving the home by installing the heat various Canadian locations, compared to winter R-12 with extruded polystyrene insulation plus
the more common Freon, further reducing their pump close to furnace or HRV exhausts. This is design temperatures for those locations. the 1 W' concrete topping, you’re going to lose
holistic ecologic profile. somewhat akin to preheating water going into a The ground is not a good heat storage me­ a minimum of 4 !4” of headroom. There really
Given that the heat pumps are transferring hot water tank, so that the heating element doesn’t dium - it is a heat sink, as in heat thrown down a is no alternative insulation option for underslab
heat energy rather than converting it, their ef­ have to work as hard. Furthermore, studies are sink drain. In addition, there is always a certain insulation. There are a couple of manufacturers
ficiencies can be upwards of 300%, whereas also under way concerning the indoor air quality amount of moisture in the soil. Very few places of foil-faced bubble wrap that claim ridiculous
electric resistive heating is 100% and gas com­ when the standalone indoor units are installed. can legitimately say that the soil is dry with mini­ insulation values of up to R-12, but that simply is
bustion around 96%. Commercial sectors prefer Air-water systems are currently not regulated mum moisture. This is important to understand nonsense. O
to use the coefficient of performance (COP) for efficiency in Canada and are not likely candi­ because water is an excellent conductor of heat
when specifying efficiencies, whereas residential dates to be regulated as there are so few of them, and has a high thermal capacity - much better Basement heat loss
applications tend to use energy factor (EF). In and the ones that are available typically have than air (which is why forced warm air heating
the air-water configuration, efficiencies are also very high efficiency ratings already. system ducts are so large, while pipes for hydron­
dependant upon the temperature of the incoming ic heating systems are quite small). Heat loss though the basement is dependent on
water being heated as well as the temperature of Information: The moisture in the soil is an excellent con­ a number of factors, including the deep ground
the air used for heat extraction. http://www.energysavers.gov/your_home/water_heat- ductor, and will pull out heat from the house. temperature, the moisture content of the soil, how
The economics of installing any type of air- ing/index. cftn/mytopic=12840 There may be a debate about how much insula­ the basement is constructed, and the time of year.
source heat pump come down to a delicate balance http://www.energysavers.gov/your_home/space_heat- tion is appropriate, and not too much research Heat transmission from the below-grade
of gas prices/availability and electrical prices. ing_cooling/index.cfm/mytopic=12620 work being done on this that I am aware of. portion of a basement cannot be calculated by
For information on Figures from BC Hydro (http://www.bchydro. http://www.squidoo.com/air-source-heat-pumps-for- The BC Building Code requirement for insula­ simple one-dimensional calculations, as is done
the R-2000 Program, com/powersmart/technologyJips/buying_guides/ cold-weather tion under heated floor slabs is sound and logical. for above-grade walls and ceilings, because the
http://en. wikipedia. org/wiki/EcoCute
contact your local water_hea ting/heat _pump water heaters, html) This applies equally to heated floors as well as soil temperatures differ across the basement wall
program office, or call show that for larger systems, payback can be as Interesting calculations using NRCAN calculator unheated floors in houses with forced warm air and floor.
1-800-387-2000 little as 0.6 years, whereas when gas is relatively http.V/www.shecco. com/inside_pages/shecco.php or baseboards. Obviously, because the heat flow As homes become more airtight and insulated,
www.R-2000.ca inexpensive and electricity is high, the systems http://oee. nrccm.gc. ca/residertial/personal/tools/cal- uninsulated or poorly insulated foundations may
may never payback. From an ecological standpoint culators/heatingcalc/compare-new-heating.cfm
though, there is no combustion involved and with
10 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 11
You Asked Us About:
Vapour Barriers
account for up to 50% of the heat used by a
I recently became a subscriber to Solplan
Canadian house. As a bonus, insulated basements Location Average Deep Winter Design
Ground Temperature Review. I was reading the article “What is yond which the moisture accumulation decreased
create a more comfortable liveable space at a
Temperature a Vapour Barrier ” in a back issue (Solplan and then became insignificant.
relatively low cost.
Because below-grade the heat flows follow Vancouver 11.3’C (52T) -9'C (16*F) Review 148, October 2009) and am some­ The reason why moisture accumulation
Calgary 6.4'C (43'F) -33"C (-27’F) decreases at a certain point is because of the heat
radial isotherms - which are generally influenced what confused. The article states that vapour
Edmonton 5.2 ‘C (41‘F) -34°C (-29T) loss - the temperature within the cavity increases
by the distance from the finished grade - codes barriers need not be continuous or airtight.
Winnipeg 6.1 *C (43’F) -35°C (-31T) with increased airflow. At a certain point, the
generally require more insulation near the grade So why then do we make such an effort to
cavity gets warmer and the conditions for con­
Toronto 11.1 ’C (52'F) -20'C (-4T)
line, and on the perimeter of a floor slab, than caulk and tape joints and punctures? Why densation cease to exist. That is why many old
Ottawa 8.9 *C (48’F) -27°C (-17T)
further in-ground and near the centre of the slab.
do we need to seal the electrical boxes at buildings without air barriers have few moisture
There is a common perception that the ground Montreal 6.4 “C (43'F) -26°C (-15T)
perimeter walls and ceilings with vapour problems — the walls are so warm that conden­
is an insulator, a heat sink, so that it is not Halifax 8.5 "C (47‘F) -18*C (-1 *F)
barrier and caulking? The article also sation cannot occur, or if there is a bit of conden­
important to insulate basements floors, or slabs- Whitehorse 2 -C (35'F) -43"C (-45T)
noted that vapour barriers should cover the sation, it quickly dries because of the addition
on-grade. However, as long as the basement is
Table shows average deep ground temperatures, of more heat. With today’s energy prices and
entire exterior surface but don’t need to be
heated, there will always a flow of energy from
compared to winter design temperatures. Basement occupant expectations, leaky, energy inefficient
the house into the ground. The rate of heat flow indoor temperatures are typically 18-20°C, while main continuous. Could you provide some more walls are not a practical solution.
may be much reduced, compared to that in the floor will be 22 °C. clarity on this issue of vapour barriers and
Although air sealing is the primary moisture
above-grade components, but it will still be there. air barriers?
driver, diffusion is also important, even though it
Water is an excellent conductor of heat, so that heat flows, modelling tools have not done a
is a lesser and more subtle driver, so vapour bar­
the amount of moisture in the soil, and whether good job of dealing with below-grade heat loses. You ask good questions about something
riers are still necessary. Thus to reduce air leak­
Software tools generally need to generalize and that continues to be a source of much confusion
it is static of flowing (as in an underground water
age, more emphasis was placed on air sealing.
average the heat loss across the foundation as­ throughout the industry.
course) will affect the heat flow. And there are
Polyethylene was found to be a simple (for
semblies. The way we build has changed to accommo­
few locations anywhere that can legitimately
many) way to provide an airtight building enclo­
HOT-2000, which is the most widely used date changing requirements and expectations in
claim that their soils are dry.
sure and also vapour barrier. So the airtight poly­
Soil temperature is important, as the greater software in Canada for housing energy analysis buildings. The use of vapour barriers was intro­
ethylene has become the norm in construction. It
the temperature difference between inside (used by R-2000, the EnerGuide Rating Service, duced in the 1930s to control vapour diffusion
is because it is being used as an air barrier that
conditioned space and the ground will affect the and others) bases foundation heat loss model­ into walls and attics. When humidification was
we see so much attention to caulking and sealing
amount of heat loss from the building. This is ling on the BASECALC program, which models introduced into houses in the 1950s, moisture
of the poly at all laps, splices and penetrations.
further complicated when one realizes that soil residential basement and slab-on-grade heat accumulation in walls and attics again became a
However, caulked and sealed poly is not the
temperatures vary across the year - the sun’s heat loss. It is based on more than 33,000 simulations problem in many homes.
only way to achieve an airtight building enclo­
works its way into the soil in the summer, to be of differing foundation conditions, including Researchers determined that most of the mois­
sure. Building scientists have realized that stop­
lost over the winter. However, the soil tempera­ insulation, height, depth, width, length and site ture was being transported into these locations
ping all moisture flows is not possible, so that
ture does not follow the season directly, so the conditions (soil conductivity, water-table depth by air leakage rather than by vapour diffusion.
in some cases extremely vapour tight enclosures
and weather). Air leakage can be a significant problem when
soil temperatures are not in sync with the outdoor
can be detrimental to the long-term durability of
air temperature. However, even these are based on averag­ the various materials in the building envelope
buildings. Very small vapour movements permit
Because of the complexity of below-grade ing the simulation results, and probably should are not installed as seamless components. There
building assemblies to dry out, and prevent mois­
be updated and reviewed as they lead to results are many holes in a building that will allow air to
ture accumulation.
that conceptually do not seem appropriate. flow into the walls and roof spaces.
With proper attention to materials selection
Many HOT-2000 simulation results suggest that Since the 1970s, the demand for energy-effi­
ciency led to the construction of better-insulated and application of details, there are other ways of
un-insulated basements or slab-on-grade floors
Building Energy Engineering houses and more airtight structures. This changed getting a tight enclosure than to rely on poly.
will be more efficient than fully insulated floors.
Remember that it is air sealing that is most
Division of N.A. Anthonsen Engineering Ltd. However, that is counter to what we know from the dynamics of wall performance.
important - so if you are achieving air tightness by
A National Research Council study looked at
Homes practice and experience.
the relationship between air leakage out of the the detailing of other materials, some of which may
MURBs The table summarizes the average deep
Niels Anthonsen, commercial building (exfiltration), heat transfer and moisture be permeable to water vapour (such as the house-
ground temperature in a number of Canadian
p£ng EnerGuide*EE4 accumulation in a standard wood frame wall. wraps), then the vapour diffusion retarder (i.e.
locations. It shows clearly that there will be
Certified Energy Advisor, LEED AP Energy Stai Using computer modelling, it was determined vapour barrier) need not be completely airtight.
Built Green some heat loss between the house and the ground that the heat flux (the rate of heat flow per unit So since the vapour diffusion is responsible
BUILDING SCIENCE* NET ZERO LEED below it, although it will not be as drastic as area through the wall) increased as the airflow for a small part of moisture movement, as long as
through the assemblies above grade.O
Victoria B.C. [email protected] 250.8X6.3142 rate increased, and the moisture accumulation most of the surface has a vapour diffusion barrier,
also increased but only up to a certain point, be- vapour transmission will be minimized, even if
it’s not perfect. O
12 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 13
Technical Reearch Committee
to the requirement that garage floors be sloped to Although the radon levels in the vast majority
News the exterior to limit heavier-than-air gas inflow of Canadian homes are below the current Cana­
into habitable spaces below the garage floor dian guideline of 200 Bq/m3, first-year results
provincial government as a result of recommen­ level. indicate that approximately 7% of Canadian
dations provided by an industry task group. It Spatial Separation between Buildings. Addi­ homes have elevated radon levels. The results
Online Building Science Research was created as an independent body comprised tional fire protection requirements were intro­ from the first year of this study demonstrate that
of broad representation from the residential con­ duced relating to the construction of all buildings radon levels vary widely across the country and
Anyone who wants to find out more about struction industry. and houses in proximity to one another or to the that there are areas where indoor radon is more
building science and building research now has The PBI will provide services related to the property line. prevalent than in others.
easy access to more than 1,400 articles, books expected introduction of minimum qualifications Penetrations Through Fire Separations. Defi­ Manitoba (24.8%), New Brunswick (21.7%),
and research reports thanks to the combined ef­ for licensed residential builders constructing or nitions for “fire stops” and “fire blocks" have Saskatchewan (16.4%), and the Yukon (15.9%)
forts of the Homeowner Protection Office of BC selling one- to four-unit residential buildings and been added, as were several changes addressing had the highest percentage of participant homes
(HPO) and the BC Institute of Technology. In will include evaluating applications for accredi­ penetrations through fire separations. Require­ where the radon levels were above the radon
collaboration with BCIT, the HPO has expanded tation of education and training providers and ments involving attics that don’t have sprinklers guidelines. Nunavut (0%), Northwest Territories
its Online Research Database which focuses on programs by accredited providers, the currency were clarified. (3.9%), and Prince Edward Island (4.5%) were
the design, construction, performance and main­ of standards, educational benchmarks and con­ Windows, Doors and Skylights. A new har­ lowest. In some regions, there are regional ‘hot
tenance of the building envelope. tinuing professional development requirements. monized North American standard for windows, spots’. For example, while BC has a low overall
The database was designed as a central online Start-up funding for the PBI will come from the doors and skylights is now referenced in the number, some regions (especially the Kootenay
resource that would be accessible to builders and HPO, with ongoing operations funded through NBC. This resulted in a substantial reorganiza­ and Okanagan valleys, and the northern interior)
others in the residential construction industry as PBI’s accreditation fees. tion of Sections 9.6 and 9.7. have quite high radon levels. However, these data
well as researchers and consumers. The database Radon. The new Health Canada guideline of are preliminary and the numbers may change
lists references as well as web links that direct 2010 National Building Code 200 Bq/m3 for indoor radon concentration has once the second year of the survey is completed.
users to sites where they can obtain the full been referenced in the Appendix. Parts 5 and 6 Health Canada is working with a number
documents. The recently published 2010 National Model now require that engineers and designers con­ of organizations, including the Canadian Lung
Since its inception in 2001, the online data­ Construction Codes contain close to 800 techni­ sider radon protection in their designs. Air barrier Association, Canadian Cancer Society and the
base has grown to a comprehensive collection cal changes. Free online presentations providing requirements in Part 9 were consolidated and Canadian Medical Association, to raise aware­
of more than 1,400 books, reports and research more detailed overviews of these changes will be prescriptive measures on providing a rough-in ness about the risks from radon..
articles that users can search at the click of a available in February 2011 on the national codes for a future radon mitigation system added. They have developed brochures, fact sheets
button. Locations where the documents can be web site (www.nationalcodes.ca). They will re­ and guides about radon and how to test and
found are primarily BC libraries, but there is place the cross-country seminars that have been Cross-Canada Radon Survey reduce radon levels if necessary.
sufficient information that anyone from other traditionally offered during past code launches. For more information:
Health Canada recently completed analysis of
regions searching for material will still find this a Some of the most significant technical chang­ www. healthcanada.gc. ca/radon
the data from the first year of a two-year study of
useful source of information. es are summarized here.
a cross-Canada survey of radon concentrations
The most recent expansion was completed
Part 9: Housing and Small Buildings in homes. The intent of the project is to gather
earlier this year as part of a long-standing part­
long-term (3-month or longer) indoor radon
nership with BCIT’s Building Science Centre Secondary Suites in Houses. Changes in
measurement results from about 18,000 homes
of Excellence within the School of Construction requirements include limiting their size, making
across Canada to get a better understanding of
and the Environment. The database, which links “secondary suite” a defined term and inserting
radon levels.
The Technical Research directly to the BCIT host site, is accessible from “house” into many requirements that previously In the first year, 9,000 homes were randomly
Committee (TRC) is the the HPO’s website: www.hpo.bc.ca. Look for only applied to dwelling units.
selected in all provinces and territories and a Solplan Review Back issues
industry’s forum for the ‘Research database’ under the Research & Edu­ Lateral Loads. New requirements for dealing
exchange of information long-term radon test was conducted during the
cation tab for a direct link. with high wind and seismic forces were added. A A limited number of back issues are avail­
on research and devel­ 2009/2010 fall and winter heating season. The
opment in the housing Professional Builders’ Institute new concept of braced wall panels was intro­ second year of the survey is underway and par­ able, at a special price of $5.75 each (plus
sector. duced (which recognizes that intersecting walls 12% HST).
ACsasnoacdiiaatni oHno, mSeu Biteu ild5e0r0s,’ The Professional Builders’ Institute (PBI) has contribute to bracing the structure). twiciniptaenr to hfo 2m01e0s /2w0i1ll1 b.e tested during the fall and issBueusn d(mlei nspimecuimal :2 a2 r caonpdioems) s aerlee catvioanila obfl bea fcokr
150 Laurier Ave. West, been established in BC to raise the bar of profes­ Low Permeance Materials in the Building All participants from year 1 of the study have only $65.00 (plus 12% HST)
Ottawa, Ont. K1P5J4 sionalism in the residential construction industry Envelope. A simplified approach to requiring the been informed of the specific radon results for Solplan Review
Tel: [phone] and protect consumers in British Columbia. correct position and properties for low air and their household and information on radon reme­ Box 86627
Fax: [phone] The PBI was formed by the residential vapour permeance materials in building enve­ diation was provided to those households with North Vancouver, BC V7L 4L2
e-mail: [email protected]
www.chba.ca construction industry in collaboration with the lopes was introduced. elevated levels. e-mail: [email protected]
Garage Floors. Inconsistencies were resolved
14 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 15
The speedi-sleeve® - a fitting solution for4"0 HRV
Ceiling Grilles and Diffusers and 2"0 Hi-Velocity Diffusers
Update: Great Canadian Reno Demo v 2.0
In the last issue we mentioned the start of work the main portion of the house is forced warm air.
on the renovation of this early 20th century North Both suites are supplied with domestic hot water
and heating by the same water heater.
Vancouver home. As seems inevitable with reno­
vations, progress is slow - winter weather and the Conceptually, the Completeheat was an in­
novative step to incorporate a combined heating
mid-winter break at Christmas when everyone
seems to take a couple of weeks off, have led to and hot water system in a single off-the-shelf
slow progress, much to the chagrin of the occu­ package that provided high system efficiency.
However, it seems that there were flaws with
pants living through the renovation.
It doesn’t help the design. The equipment was pulled from the ... for retrofit
that the owners market a few years ago, and Lennox stopped applications,
providing support.
decided in the try adding a
course of con­ As the mechanical contractor started work­ clamping ring
struction that a ing on the heating system, he discovered that the
few changes were Lennox Completeheat unit had rust at its base
in order - moving and appeared to be on its last legs, requiring
a few walls and new heating equipment. It appears that the unit
windows around - had been leaking for some time, but the leak had ENEREADY PRODUCTS LTD. ££
but that’s some­ gone unnoticed. The problem is that the unit was #4 - 6420 Beresford Street • Burnaby • British Columbia CANADA • V5E 1 B6
thing renovators installed only 10 years ago - in January 2001. It Telephone: [phone] • Fax: [phone] • www.enereadyproducts.com
understand well. turns out that Lennox had abandoned the unit a
The roof has few years ago and no longer even has spare parts.
We’ve been told that getting 10 years of ser­
finally been re­
placed, and struc­ vice was better than many got. We’ve also since
heard that there are rumblings of class action
tural upgrades
House under protective tarps have been made, lawsuits in the US.
A 10-year service life for a not inexpensive
so that work can
proceed - shoehoming contemporary mechanical mechanical system is simply not right. We know
POWERHOUSE BUILDING SOLUTIONS INC.
that mechanical equipment is made by people
systems into a hundred-year old house.
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The heating system in the house was a and is subject to require periodic maintenance.
combined heating and hot water system. A solar But equipment that the manufacturer abandons
thermal system preheated city water, which was after a few years on the market, and doesn’t even
then heated by a Lennox Completeheat high effi­ provide replacement parts for is scandalous.
ciency condensing water heater. The ground level The challenge is that, as we move to improve
suite is heated by in-floor radiant heating, while the efficiency of our buildings, codes and stand­ MetroWrap
ards are pushing for ever more efficient systems. Perm-A-Barrier VPS
\ Consumers need to be sure that the equipment Commercial-Grade Building Wrap Breathable Peel & Stick”
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16 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 17
Energy Answers
tiles. The floor tiles are prefabricated concrete The house has a 4.4 kW peak PV system tilted
Can you tell us more about the VerEco Net
tiles 1.25 inches thick. The tiles serve three pur­ at an angle of 62 degrees from the horizontal.
Zero Energy Home in Saskatoon? poses—they provide a finished floor, they help Note that between January 14 and 16 the PV
moderate temperature swings from solar gains production was minimal—this was caused by a
The VerEco Net Zero Home in Saskatoon was during the heating season and they also help combination of cloudy days and heavy snowfall
opened in October 2010. The house is on display moderate temperature swings in the summer. that radically reduced the PV output. On January
at a local museum until August 2011, and then The house was pre-fabricated off site and 17 the panels were cleared off with a roof rake
Figure 4. Meter showing the instantaneous
it will be moved to its final site and placed on a moved in one piece to the exhibit area. Sas­ and the PV production resumed.
basement. The house is a modest bungalow in katchewan has quite generous rules as to the size The TED 5002 G greatly helps in tracking the
size, with 1,440 square feet on the main floor. of new homes that can be transported, and this energy performance.
1,440 square foot house was readily moved. For The house sits on a crawl space, and during
a short video showing the move, have a look at the open house there is no insulation in the floor.
Rob Dumont, Ph.D.
http://www.youtube.com/watch?v=cp34vBuRshQ Thus, roughly 2/3 of the heat loss from the house
The house is open six days a week for 10 is into the crawl space. As can be seen from Fig­
months at a popular museum site. Especially im­ ure 5, the total energy consumption of the house
portant are the elementary school tours, as kids (there are no sources of heat such as a natural gas
in Grade 7 science are taking material on energy, furnace or boiler) is very modest. (1 kilowatt =
and the house tours will help a lot in explaining 3,413 BTU/h).
principles of energy and water efficient design.
(We haven't had all that much success educating The key to the outstanding performance of
Figure 1. VerEco Net Zero Home Exhibit in adults in North America about sustainable hous­ the house is the outstanding energy conservation
Saskatoon ing, so perhaps getting people at an earlier age design. With the greatly decreased loads, the re­
will help.) electrical energy> consumption of the house. newable energy sources - passive solar gain, the
What are some notable features of the Net
A weekly series of lectures given at the house active solar thermal and the photovoltaic panels -
The TED unit will also graph the energy con­
Zero Home?
are being videotaped and available on Youtube. are projected to generate enough energy to make
sumption and production for the house. In Figure
The Net Zero home is likely the coldest Go to http://www.verecohome.com/expertseries/ the house Net Zero in annual energy consump­
5 a graph of a 7-day interval is shown.
NZEH home in the world (in location, not in for a listing of the talks that are available. tion once the house is moved onto a basement.
interior temperature). To my knowledge, no one A relatively inexpensive device (about $280
in a colder climate has built such a house. Less plus shipping) called a TED 5002-G allows one
than 1% of the world’s population lives in as cold to monitor the house electrical consumption and
a climate as in Saskatoon. If it can be done in photovoltaic generation over the internet. An
Saskatoon, it can be done anywhere in the more electrician or experienced electrical person is
populated and warmer parts of the planet. needed to attach the TED unit to the main electri­
The home may have the best insulated cal panel. A view of the Dashboard output from
residential attic in the world. The attic has an the VerEco Home is shown on the wall mounted
R-value using cellulose of about 110 in English LED TV hooked to a computer in Figure 2. _____
units (RSI 19.5.) I used to think that my house, The TED unit collects historical data as well as Figure 5. Graph of hourly energy consumption
with R-80 in the attic, was at the outer limit. Not instantaneous. and PV production at the VerEco Home for
so any more. Figure 2. Interior View of the VerEco Home January 12 to 19, 2011.
The walls are double stud walls with about
R-60 blown-in cellulose insulation.
As can be seen from the graph, there is a
The flat plate solar thermal panels are mount­
period on January 15 and 16 when the energy
ed vertically on the south wall. (Saskatoon is
consumption increases dramatically. During
located at latitude 52 degrees north.) In addition
these periods, a worker was outside on the
some evacuated tube solar thermal panels are
temporarily hoarded front porch, and was using a
located vertically on the front of the deck on the
220-volt construction heater. The high consump­
west edge of the south side of the house. (These
tion for those periods is evident from the graph.
evacuated tube panels have not yet been con­
The light coloured bars below the 0 axis are the
nected to the heating system.) These locations
PV production.
for active solar panels give more design freedom,
although at a penalty in energy performance.
showing the wall-mounted LED TV with the TED
Additional thermal mass is present in the floor
Dashboard.
Figure 3. Dashboard for the TED-5002 G Unit
18 SOLPLAN REVIEW January 2011 SOLPLAN REVIEW January 2011 19
ARCCARC
contro of floor slab
Changes to the 2010 NBC for Radon
Two possible arrangements are shown in Figure
Protection in Dwelling Units 2.
The building should be retested for radon after
extraction of gas. An inlet needs to be provided
The 2010 National Building Code has revised that allows for effective depressurization of completion and activation of a depressurization
the requirements for protection from soil gas, in- the gas-permeable layer. An outlet needs to be system. For further information on how to meas­
ure and remediate existing houses please refer to
By Frank Lohmann eluding radon, intended to address the reduction provided that permits connection to depressuriza­
in Health Canada’s acceptable level of radon tion equipment sealed to maintain the integrity guides from CMHC and Health Canada: Radon:
from 800 to 200 Bq/ m3. of the air barrier system. The outlet should be A Guide for Canadian Homeowners', and Guide
clearly labelled to indicate that it is intended for for Radon Measurements in Residential Dwell­
Radon ings (Homes).
the removal of radon from below the floor-on-
Radon is a colourless, odourless, radioac­
ground. An example of this method would be a
tive gas that occurs naturally in the environ­
sump chamber that is sealed to the air barrier,
ment. Outdoors, its concentration is rendered
which can be connected and used to exhaust air
negligible. But when it is emitted into an en­
from beneath a floor-on-ground.
closed space, such as a building, it can accumu­
The second method is more specific and
late to high levels and be a carcinogen. Radon
requires a 100-mm layer of clean, granular mate­ contro of floor slab
can seep from the ground into buildings through
rial under the floor on ground and a pipe at least
cracks and unsealed penetrations in the floor and
100 mm in diameter through the floor. The lower
walls abutting the ground.
end of the pipe extends into the required granular
Measuring Radon in Canadian Buildings layer.The top of the pipe must be fitted with an
Although there are regions in Canada where air-tight cap. If the pipe rough-in is located close
high radon levels are known to occur, it cannot to an exterior wall or into the service area of a
Figure 2. Two types of sub-slabdepressurization
be concluded that radon will not be a problem at basement, normal plumbing pipe can be used Figure I. Acceptable inlet/outlet
systems.
other locations. . First, a reliable and comprehen­ to connect the vertical pipe to the center of the configurations for the rough-in of a future
sive radon map for Canada does not exist. Sec­ sub-floor. If the sub-floor space is interrupted by depressurization system.
ond, it is possible for high radon concentrations internal footings, it is important to ensure that the
to be present in one building while neighbouring collection system is capable of depressurizing
buildings might not have elevated concentra­ all areas. Possible configurations are shown in
tions. Last, it is very difficult to detect problem­ Figure 1. SPRAY FOAM INSULATION
atic radon concentrations during construction. Unheated (not conditioned) crawl spaces do
Because mitigating high radon concentrations not need to be protected against the ingress of
after construction is complete could be very radon because venting an unheated crawl space
expensive, providing provisional measures at can be used as an effective radon mitigation
the time of construction can increase safety system, should it become necessary. Heated FOUR SEASONS INSULATION LTD.
and reduce the cost of future mitigation. This crawl spaces are exempt from the requirement to
is the approach that was used for the 2010 provide a rough-in for a future radon extraction Serving the Building Community for 40 years!
code changes. system if the crawl space does not have a con­
crete floor slab and if it remains accessible such
Changes to the 2010 National Building Icynene Insulation and Air Barrier
that a person could easily install a connection to
Code for Radon Healthier, Quieter, More Energy Efficient®
the sub-air barrier space to be used for the radon
Protection from soil gas ingress is now Spraying foam for over 20 years
extraction system.
required in all buildings. This protection is Locations throughout B.C.
achieved by requiring a continuous air/soil gas Testing for Radon and Activating the
Centra! Okaaasan I
barrier. The 2010 NBC provides specific protec­ Depressurization System Call us for a FREE estimate &
tion against future radon ingress into conditioned Testing for radon after a building is occupied
Lower Mainland [phone]
. , . spaces in Part 9 buildings by requiring one of the is left to the building owner. If the results of the
Frank Lohmann is a senior fo'llowing, two meth od,s: test indicate an annual average radon concentra­ Toil Free [phone] Whistler [phone]
technical advisor at the
The first method is fairly generic and requires tion exceeding200 Bq/m3, the completion of the Naniamo [phone] Victoria [phone]
Canadian Codes Centre,
Institute for Research in a gas-permeable layer between the ground and subfloor depressurization system may be neces­ Kelowna (250) 861 -3626 Seachelt [phone]
Construction, National the air barrier that allows for depressurization of sary to reduce the radon concentration. Although Kamloops [phone] Vernon [phone]
Research Council of the space below the soil gas barrier. This layer not covered by code provisions, this requires that www.fourseasonsinsulation.com
BBB.
Canada. could be coarse sand, a dimpled membrane or the rough-in pipe be uncapped and connected to www.icynene.com
another product that allows the collection and a ventilation system exhausting to the outside.
1*1 National Research Conseil national
Council Canada de recherches Canada