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Passive House – It‟s Here!By Stuart Fix
Acknowledgements
• Special Thanks:
2
About the Author
• Stuart Fix, EIT, CPHC, LEED AP
– Born & raised, Stettler, AB (1983-2001)
– Mechanical Engineering, UofA (2001-2006)
– Oilfield Machine Design, AB & Oman (2006-2008)
– MASc. Building Science, Ryerson (2008-2010)
– Drinking the Passivhaus Kool-Aid (2009-2010)
– Residential Mechanical Systems Design GTA (2009-2010)
– Director, Passive Buildings Canada (2010-2013)
– PHIUS Consultant‟s training (Summer 2010)
– Vital Engineering, sharing the PH Kool-Aid (2010 - present)
3
Presentation Summary
• Passive Building Design
• Examples of Passive Buildings
• Passivhaus
• Germans and Their Numbers
• How is this Achievable?
• Built Examples
• Passive House Planning Package (PHPP)
• Cost Implications
• PH Organizations in North America4
Questions?
• Please! Ask questions at any point during the presentation.
• If the answer is too long, it‟ll have to wait.
• If the answer is political, save it for the pub.
5
Passive Building Design
• Moderate Climate Passive Design
– Large south glazing
– Thermal mass
– Trombe walls
– Cross and stack ventilation
• Northern Passive Design
– Super Insulation
– Super Air Tightness
6
REF - Image 1
• The sun is our most abundant, most reliable source of energy
• „Passive‟ design → Winter solar energy can be captured and
retained in buildings, while Summer solar energy is not.
Moderate Climate Passive Design
7
• The Greek Philosopher, Aeschylus (525-456 BC):– “Only primitives & barbarians lack knowledge of houses turned to
face the Winter sun”
• Large south windows and thermal mass dominate Southern
Passive design.
REF – Image 2 REF – Image 3
Northern Passive Design
8
• Northern Passive design is more recent, dominated by
super insulation, air tightness, and balanced window size.
• Lo-Cal House
– Illinois, 1976, super insulated, triple pane windows
• Saskatchewan Conservation House
– Harold Orr, 1977, super insulation & 0.8ACH @50Pa
REF – Image 4 REF – Image 5
Passive Design Issues
• Too much southern glazing results in
radical indoor temperature swings,
which coupled with thermal mass leads
to overheating in the summer
• Improper use of super insulation
without attention to air tightness can
lead to condensation buildup within the
building envelope (leads to mold)
• Improper use of air tight construction
can lead to indoor air quality issues,
without proper ventilation systems
9
What is Passivhaus?
• Passivhaus → German Engineered Passive Design
• The Passivhaus Standard presents a highly transparent,
repeatable, & validated method for using Passive Design
ideas to deliver extremely energy efficient buildings
• The standard was founded in 1996 by Dr. Wolfgang Feist,
based upon 25 years of research as a building physicist
• The standard has remained largely unchanged, and still
produces the most energy efficient buildings in the world10
The First Passivhaus
• Dr. Feist built his first Passivhaus in 1991 in Darmstadt,
Germany
• A duplex, was built with optimized glazing ratios, R52
ceiling, R41 walls, R43 slab.
• Achieved 0.2ACH@50Pa air tightness11
Passivhaus Performance
• Relative Site energy consumption of EU Passivhaus buildings
12
Importance of Efficiency
• Passivhaus focuses on efficiency before renewable energy
13
Into North America
• The German „Passivhaus‟ translates directly to „Passive
Building‟ in English, but the name „Passive House‟ (PH)
has instead been adopted in North America.
• This has caused confusion…
• Don‟t mistake „Passive House‟ with traditional „Passive
Solar Design‟
• Passive House applies to all building types, even though
its name implies it‟s a residential-only method 14
PH Prescriptive Performance
• PH Buildings must satisfy 3 performance targets:
< 15 kWh/m2a Heating/Cooling Demand
< 0.6 ACH@50PA Air Tightness (pos & neg)
< 120 kWh/m2a Primary Energy Consumption
• These targets are constant for all climate zones
15
Germans and Their Numbers
• The PH performance targets have
been criticized for being arbitrary
and irrelevant for non-German
locations
• Since when is German
Engineering arbitrary?
• There is strong scientific,
economic, & environmental
reasoning behind these targets
16
Heating Demand Target
• The 15kWh/m2a target represents the amount of heat
that can be delivered through ventilation air, in Germany
• If heat demand is reduced to this level, one can „tunnel
through the capital cost barrier‟ to find savings17
REF – 1
Heating Target Explained
• Ventilation air flows can only carry about 10W/m2 peak heating load. In
Germany, limiting peak heat load to this will result in annual heat
demand under 15kWh/m2a. (Explain Heat Load vs. Demand?)
• Canadian climates are colder than German, but have more sunshine.
Result is higher night heat load, but lower day heat load, which actually
balances out nicely.
• Heating solely through ventilation in Canada would require lowering
annual heat demand to less than 10kWh/m2a.
• It‟s cheapest to add some electric heating to supplement ventilation heat
delivery, and stick with the German 15kWh/m2a demand target.
• Canadian Passive House buildings will have more insulation and slightly
larger heating plant, but still use the same annual heating energy as
German PH buildings.18
Air Tightness Target
• Moisture damage is dominated by air
leakage, not vapor diffusion. Vapor open
construction is even encouraged.
• 0.6 ACH@50Pa target is the level of air
tightness that removes nearly all danger of
moisture damage, even within a vapor
sandwich wall construction.
• Reduced infiltration also saves heating
energy. We are encouraged to push the
envelope, projects in Germany are hitting
<0.1ACH@50Pa!
19
Primary Energy Target
• The 120kWh/m2a primary energy consumption is based
upon the 1992 Earth Summit consensus
• It corresponds to the per capita annual carbon dioxide
production that allows a sustainable global environment
• It‟s the level under which we can afford the
unpredictable future costs of fossil fuels and therefore
maintain an economically feasibility long term society.
• Hence why it applies in all climate zones, Northern
climates don‟t get a free lunch.
20
Building Implications
• Designing to a Energy / Floor Area target penalizes small buildings.
• It takes higher insulation levels to get a 1000ft2 home to PH than a
2000ft2 home of the same shape.
• This is good as it encourages us to build larger, shared buildings, which
are inherently more energy efficient.
21
• This is bad, as one can cheat and
build larger single family homes.
• Designers must be aware of this!
PH ?
Achieving PH Performance
• The Typical Approach:– Double stud, Larson truss, or TJI envelope type
– Thermal Bridge Free construction - Typical construction TB‟s account for
15kWh/m2a, Super insulation & air tightness alone won‟t do it!
– Air barrier + Wind screen barrier approach for durability (double sheathing)
– Separate architectural drawings for continuous air, wind, vapor, & thermal
barriers (follow each around the building without lifting your pen)
– Efficient building shape, less than 1m2/m3 surface area to volume
– Optimized window design that gives more solar heat gain than transmission
loss throughout the heating season, without discomfort
– Efficient HRV‟s, above 92% heat recovery, and less than 0.7 W/CFM22
PH Wall Details 1
• Exterior walls are cantilevered over slab/foundation walls, NO break
in insulation, air barrier, vapor barrier, etc and simple construction.
• Details that have thermal bridging greater than 0.01 W/mk must be
modeled in THERM.
23
PH Wall Details 2
• Walls are
sheathed with
OSB on interior,
which forms the
main air & vapor
barrier (can add
poly behind too)
• Services are run
in interior cavity
• Fewer
penetrations
• Simple air sealing
details (taped
sheathing)
24
PH Wall Details 3
• Floor joists
screwed through
OSB into interior
studs of Larson
truss, double stud
wall, TJI, etc
• Also can be hung
with special
brackets
25
Wall Details 4
• Modified
Larson
Truss Style
• Prefab or
built on site
26
Wall Details 5
• Note the wind &
air barriers
• Small TB in the
corner
• Alternative to
service cavity is
to run baseboard
electric, and
keep plumbing to
interior walls.
27
Penetration Details 1
• Tapes &
Boots, no
Caulking or
sealant!!!
• SIGA, 3M,
VARIO,
manufacture
these
products,
order online
28
Penetration Details 2
29
• Air admittance valve to replace plumbing vents, allows venting
without envelope penetrations, and prevents cold air backflow
Air Sealing
• Air sealing is taken very seriously,
like the hull of a ship!
• Blower door testing before air barrier
is covered
30
Insulation Selection
• Natural, Low embodied energy insulations
are favored, typically cellulose or rock
wool. No flabby batt insulation. EPS for
foundation walls & sub-slab.
• No wet blown cellulose. Best practice
blowing uses ISOCELL Nozzle, into
sheathed walls. Achieves continuous 3.5
to 4 lb/ft3 in-wall density (Austrian Tech)
• No spray foam! Danny Harvey‟s research
[REF 2] shows that nearly all spray foam
blowing agents have huge global warming
potential (CFC‟s, HFC‟s, Pentane, etc).
• Spraying R40 Foam walls results in 60-
125yr global warming payback!31
Operational vs. Embodied Energy
• Op energy dominates lifetime balance, even of super insulated homes32
Insulation Embodied Energy
• Straw bale, cellulose,
and mineral wool have
least embodied energy
• Note carpet, linoleum
have more embodied
energy than recycled
steel & aluminum!
33
Continuous Insulation
• Small breaks in insulation have a large impact on heat
loss, wind tight exterior sheathing is important34
PH Mono-Slabs
• Slab is poured into
insulation formwork
• Basements
uncommon in Europe,
but same method can
apply.
• Pour foundation walls
on top of basement
mono-slab
35
Slab On Grade Examples
36
PH Windows - 1• Net heat gain window design
– Optimally sized windows with low Uvalue (<0.8 W/m2K) and high SHGC (>0.5) can capture
more heat than is lost in the heating season, even in Edmonton.
– Overall at least R7 window, requires Rglass between 8 to 11, and Rframe of 7 to 9
– North American windows have a tough time meeting this criteria
37
PH Windows - 2
38
• Windows should be
installed in the center
of the wall, to minimize
isotherm disruption
(which results in least
heat losses)
• Internal surfaces must
be kept warm for
occupant comfort
• max 2.5°C surface
temperature difference
within the building
PH Windows - 3• Lift & Slide Doors, R8 overall, very air tight. Double hung windows and normal
sliding doors are too leaky.
39
PH Windows - 4• “Shading has little influence on poorly insulated buildings, the sun heats right through the
façade” – Manfred Brausem
• External shading of summer solar gains is of utmost importance in Passive House buildings,
otherwise overheating will certainly occur
• Use overhangs, vertical slat elements, accordion type shades, integrated window shades,
deciduous trees, or any combination. These should be architecturally pleasant. 40
PH Mechanical Systems 1
• The simplest mechanical system delivers heat over ventilation system.
100% Fresh air delivered to habitable rooms, contaminated air extracted
in balanced fashion. Charcoal recirculation filter on kitchen range.
• Passive pre-heat from air or liquid source ground plumbing (HRV defrost)
41
PH Mechanical Systems 2
• The best HRV / ERV available in North America are the UltimateAir
RecoupAerator (Ohio) and the Zehnder ComfoAir (German import)
• Greater than 95% energy recovery, using less than 0.7W/CFM (70W for
typical home at 100CFM airflow)42
PH Mechanical Systems 3
• Passive House buildings can be heated by point source heaters, as long
as the output is low temperature. An easy supplement to ventilation or a
stand alone heat source in Canadian climates.
43
PH Mechanical Systems 4
• European technology goes a step further, integrates domestic hot water,
HRV, and space heating into a magic heat pump box. Incredible efficiency,
and No mechanical room required! (European products incoming, 3 yrs)
44
European Examples 1
• There are nearly 30 000
built PH examples in
Europe, of all building
types [Feist,2010]
45
• Currently, 10-12% of new
builds in Germany and
Austrian are PH [REF – 3]
European Examples 2
• Examples exist in
nearly all climate zones
(Abu Dhabi & Alps)
• Alaskan attempts,
getting closer with heat
storage.46
European Examples 3
• Summer shading control, with exterior shades, is incredibly important,
otherwise overheating will occur. But they can be well hidden.
47
High Rise Floor Plan
• High rise floor plans must give solar access to every unit
(no double loaded corridors)
48
[REF – 4]
US Examples 1
• Townhouses in Urbana, IL
• Rue/Evans Home, Portland, OR
• Biohaus School, Bemidji, MN
49
US Examples 2
• Isabella Lake, MN
• Martha‟s Vineyard, MA
50
• PH can be affordable or high end!
• There are 30 certified US buildings,
over 45 in the pipe.
The Canadian Example
• There is… ONE certified PH building in Canada, the
Austrian Athlete's House in Whistler, BC. This was donated
by the Austrian Government during the 2010 Olympics.
• There are at least 10 PH projects underway in Canada, in
Quebec, Halifax, Regina, Edmonton, Calgary, & Vancouver51
The PHPP - 1• The Passive House method uses an excel-based software package, the
Passive House Planning Package (PHPP)
• Simple to use, yet powerful tool for optimizing Passive Building Design
• Certification is based upon the PHPP predicted performance falling under
the heating and primary energy consumption targets, coupled with the
constructed building passing the air tightness test requirements.52
[REF – Image 7]
The PHPP - 2
53
• The software is highly validated, and accurately predicts building performance.
Verifying the building air tightness at <0.6 ACH@50 is important to this
predicted vs. measured performance.
[REF – Image 8]
PH Cost Implications - 1
• Experienced European builders have the
PH capital cost premium down to 5% of
total building cost. ($300k traditional
building or $315K PH building)
• American examples are showing that the
first try by a designer / builder will likely
be more like a 30% premium
• By the 2nd-5th, this will drop to a 10-15%
premium, and 5% is on the horizon
• Practice makes perfect!
54
PH Cost Implications - 2
55
• In Europe, a life cycle cost analysis with reasonable future
energy costs shows great logic behind the Passive House
approach.
[REF – 1]
PH Cost Implications
• To the cost spreadsheet!!!
56
Passive House Organizations
• Canadian Passive House Institute (CanPHI)– www.passivehouse.ca
– Circa 2009, offers training and building certification services through PHI
• Passive Buildings Canada (PBC)– www.passivebuildings.ca
– Circa 2009, offers information network for Canadian professionals, builders, and technology suppliers
• Passive House Institute United States (PHIUS)– www.passivehouse.us
– Circa 2002, offers training and building certification services
• Passive House Alliance (PHA)– www.phalliance.com
– Circa 2008, offers information network for US professionals, builders, and technology suppliers
• Passive House Institute (PHI)– www.passiv.de/07_eng/index_e.html
– Circa 1996, the origin of it all, provides training, building certification, and research
• International Passive House Association (iPHA)– www.passivehouse-international.org/
– International information network for professionals, builders, and technology suppliers 57
In Summary…
58
• Passive House buildings:
- Are based on the long term economical
sustainability of global society
- Take construction quality to a new level, resulting
in incredible performance and durability
- Provide fantastic indoor comfort and air quality
- Can provide a good return on investment if
implemented intelligently
- Are now in Canada!!!
References
59
• Image 1 - http://www.esru.strath.ac.uk/EandE/Web_sites/01-02/RE_info/passive_urban.htm
• Image 2 - http://www.thenaturalhome.com/htmexterior.htm
• Image 3 - http://www.desertearthandwood.com/
• Image 5 - http://www.indigogreenstore.com/green_building/index.php?option=com_content&view=article&id=270:solar-vs-
super-insulation&catid=38:blog&Itemid=1
• Image 6 - http://www.arch.uiuc.edu/programs/engagement/brc/publicationsforsale/brc/conservation/
• REF 1 – Lausten, Jens. Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings.
International Energy Agency, 2008.
• REF 2 – Harvey, Danny. Net Climatic Impact of solid foam insulation produced with halocarbon and non-halocarbon blowing
agents. Building and Environment Journal, 42 (2007) 2860-2879.
• REF 3 – Feist, Wolfgang. http://www.greenbuildingadvisor.com/blogs/dept/musings/conversation-wolfgang-feist
• REF 4 – Brausem, Manfred. PH Architect, Köln, Germany.
• Image 7 - http://www.passivhaustagung.de/Passive_House_E/PHPP.html
• Image 8 - http://www.passivhaustagung.de/Passive_House_E/measured/Vgl_PHPP_Verbrauchsmessung_big.png
60
Thank You!
Any Questions?
“The idea that an upgrade to a home might pay for itself is pretty exclusive to
Passive House! ”
- Randy Foster, The Artisan‟s Group, WA
Stuart Fix, EIT, LEED AP
Certified Passive House Consultant
MASc. Building Science
Mechanical Engineer
Vital Engineering Corporation
No. 223, 52 Sioux Road ● Sherwood Park, Alberta, T8A 4X1 ● P. 780.416.8336 Ext. 227 ● F. 780.416.8620 ● [email protected]