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The house with no furnace

Amazing heat in an amazing home By Steve Maxwell


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April 26, 2012 by Robert Koci

Reiner Hoyer is an award-winning Toronto contractor with 30 years experience, and he’s just completed his favourite project of all. Not surprisingly, it’s a house he built for himself and his wife Melanie, though this fact alone isn’t why Hoyer’s smiling these days. Energy performance and indoor air quality are the main reasons he’s so happy, and you can’t blame him. Hoyer’s house brings together enough leading edge construction technology that the structure requires no outside supplemental heat. Even when temps drop to -10ºC outdoors, the thermometer still reads a cozy +23ºC inside, thanks to nothing more than the incidental heat given off by high-efficiency lighting, small rooftop solar collectors, cooking and body heat. No furnace, baseboard heaters or gas fireplace necessary. Reiner’s house is gorgeous, too – no glass greenhouse look here. Indoor air quality is fresh and healthy, and anyone can build a house like this for five per cent to 10 per cent more than an ordinary custom home, says Reiner. All in all, it’s more than a good news story. Hoyer’s project proves how ultra-high efficiency housing is possible in the real world using real trades and materials that anyone can get.

Hoyer’s project began with an energy guzzling 1950s Toronto bungalow. The basement and one exterior wall was saved to meet zoning requirements to allow a rental suite in the basement. The end result is an elegant, three story home built following design parameters of the Passive House movement. (www.passivehouse.ca). Not to be confused with “passive solar” houses, Passive Houses use efficient building shape, solar exposure, superinsulation, advanced windows, leading-edge ventilation and subtle technical features that require little or no energy inputs from conventional heating or cooling systems. There are 30,000 Passive Houses in Europe right now, but the idea is new enough in Canada that Hoyer’s project was almost strangled by building department red tape before it ever got going. According to Hoyer, the inability of the building inspection department to efficiently recognize new-to-them construction technologies that are proven and used elsewhere was a bigger challenge than building a house that stays warm in Canadian winters without a furnace. To learn more about the bureaucratic challenges of Hoyer’s project, see “Old Dog Snarls at New Tricks” on page 47.

Super-Insulated, Super-Sealed

Retaining energy investments in heated and cooled air indoors is job one with any Passive House, and code-minimum levels of insulation will never do this job. That’s why Hoyer built exterior walls with roughly double the usual amount of insulation: R60 for south, east and west walls, R70 for north-facing walls and R90 in the attic. But R value alone isn’t the only issue when it comes to insulation. In fact, R values are not even the most important issue.

Almost all the insulation Hoyer used is some kind of foam – either spray or rigid sheets – and there’s a reason for it. Foam delivers consistent energy performance. It’s unaffected by drafts and air movement. By contrast, fiber-based batts are a different matter entirely. Real world batt insulation values are sometimes lower as air movement and drafts travel through wall frames. You simply cannot build a Passive House without foam.

Perhaps the most unusual part of Hoyer’s house is the approach he took to insulating the basement. He used a full coverage design that put sheets of extruded polystyrene foam on walls, sealed under a layer of soya-based spray foam insulation. Spray foam is also continuous over the entire surface of the existing concrete floor of the old bungalow, with floor insulation values topping out at R60. Four inches of reinforced concrete was poured on top of this floor foam, encasing radiant infloor heating pipes. Metal stud walls sit on top of this concrete floor, located just inside the foam sprayed on exterior walls. The end result is complete thermal isolation from the earth, with a basement floor that acts as a massive thermal flywheel.

The outside three walls of the house are finished in synthetic stucco, and it’s applied over a whopping six inches of expanded polystyrene foam that’s anchored to a wall retained from the old house. Ray-Core SIPs were used to create new exterior walls elsewhere.  The front of the house is finished with a stone veneer that’s applied over a two inch-thick layer of spray foam applied over the SIPs.

The attic is filled with 30” of blown-in cellulose insulation, amounting to a whopping R90 of heat retention. A laser level was used during installation to ensure even and complete attic insulation coverage.

Besides superior insulation performance, Hoyer’s heavy use of foam offers another big pay-off. Spray foam seals out drafts like nothing else can, and low air infiltration is key to meeting Passive House standards. Nothing more than 0.5 air changes per hour (ACH) is considered acceptable, and Hoyer’s house came in at an impressive 0.27 ACH, despite retention of an existing wall and basement from the old bungalow. That’s 11 times less air leakage than some of the tightest new building code standards coming into effect right now.

Hoyer chose triple pane Geneo windows delivering R9.5 centre-of-pane insulation values. The frames are made from a proprietary blend of fiberglass and PVC that’s strong enough to function without need for metal reinforcement. It’s the same material used to make the bumpers of German cars, and even the dark colours don’t expand and warp with the
sun’s heat.

Vacuum Tube Solar Collectors

Building code requirements forced Hoyer to install an air-to-air heat exchanger as a back-up heat source, but it’s mostly just for show. The small amount of energy required for space heating beyond what’s produced internally by cooking, lighting and human bodies is usually supplied by a rooftop vacuum tube solar collector. It provides domestic hot water, too. The vacuum tube design greatly boosts heat-gathering action during cold weather. One sunny day when it was -10ºC outdoors, for instance, the vacuum tube system heated Hoyer’s 500 litre water storage tank all the way up to 60ºC. Space heating is delivered through a Rehau hydronic infloor system that also extends out onto the concrete front porch for melting ice and snow.

 Fresh Indoor Air

Hoyer installed an HRV made by the European manufacturer Paul. The Novus 300 unit he chose extracts 99 per cent of outgoing heat in stale air, compared to 70% to 80% for typical HRVs. Part of this amazing performance comes from the ground loop intake air supply. Air drawn into the HRV first travels through 90 feet of eight inch diameter buried pipe. Even when it’s -15ºC outside, incoming air is a much friendlier 5ºC to 6ºC as it enters the HRV. In a sense, it’s like a mini ground source heat pump without any extra equipment. A humidity recovery coil in the HRV captures and recycles moisture from the outgoing air stream, eliminating the need for a humidifier. Hoyer’s currently working on plans to install a Geyser hot water heat pump to capture the heat lost by the HRV for supplemental heating on cloudy days. This heat pump will leverage the heat lost by the HRV, delivering an efficiency of about 300 per cent.

At first glance, Hoyer’s project is impressive for practical reasons. Any Canadian house that stays warm without a furnace deserves front-page coverage. But more important than this, Hoyer has advanced the definition of what’s practical and possible in the real world. Why would anyone settle for anything less?

 

The right trades

The building work itself also posed challenges beyond the usual ones. “On the construction site, I had to constantly coach every trade carefully at each step of the way, since so much of this house involved unique and crucial processes,” explains Reiner. “No one could understand, for instance, why basement insulation was going up on walls and floors before framing, wiring and pipes went in. In the end, when they saw how the approach created a perfect shell of insulation and air tightness, they understood. You’ve got to choose your trades carefully. Their willingness to learn and work differently—without killing your budget—is key.  From my experience, younger trades are more open minded and easier to teach than the guy who’s been God’s gift to the construction industry for the last 25 years.”

Does Hoyer consider all the trouble worth it? “Absolutely. Living in a house that cost me less than $20 a month to heat in the middle of winter is a great thing. My wife’s breathing problems are a thing of the past now, too. Anyone can build this way at a budget very close to any ordinary custom home.”

 

 


Robert Koci

Robert Koci

Rob Koci is the publisher of Canadian Contractor magazine. rkoci@canadiancontractor.ca Tel. 647-407-0754


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28 Comments » for The house with no furnace
  1. David Zwarych says:

    Why would concrete be required at all ON TOP of R50 floor insulation?

    Can’t a plywood sub-floor or engineered wood floor be installed directly on top of insulation sheets? There is no air infiltration from under the earth right?

    I suspect the “extra cost” of all that expensive technology in radiant heating isn’t justified or required at all when R50 insulation is added…since there isn’t any extra benefit of “heating” a surface when it is already at “room temperature” (my previous question “Can your toddler crawl around on your basement floor?” was unanswered)

    If super-insulation creates a passive house that eliminates the need for a furnace…doesn’t it follow that it also eliminates the need for a premium priced in-floor radiant heating system, geothermal heating or solar heating systems too? Or is the allure of using sexy renewable technology just too attractive to resist?

    DaveZ

  2. Bruce MacKinnon says:

    Truly impressive, but how much more did this cost really?

    • Horia Albu says:

      Hello Bruce MacKinnon, your answer is in the first paragraph of this page, and if my memory serves me, it is 5 to 10% more “than an ordinary custom home”… but more interesting will be the development of the heat recovery device, that Reiner Hoyer is working on, [ heat recovery from an HRV ?? (Heat Recovery Ventilator)] I would think that he is trying to increase the efficiency of his HRV.

  3. Helena Bales says:

    Hi,

    We are thinking about purchasing a home with out a basement. Yes, no furnace and no HVAC in the house. The house is two stories, sits in St. Catherines Ontario where temperatures do get as cold as minus 20.
    It has one gas fireplace and heated by electrical floor boards.

    Our goal was to push the two main floors 15 feet forward, add two gas fireplaces with a open stair case in the middle to allow heat to rise. I also wanted to heat the floors on the main level.
    I will add duct work for a central vac if allowable.

    Is this a good idea or do you recommend that we dig underground and put a furnace in place.
    The house is roughly 50years old. My father stated, the house has rotted below, and you should be careful what you purchase.

    The land is located just behind Lake Ontario. It is a prestigious ravine lot overlooking the lake.

    Your thoughts are appreciated.

    Thanks Helena

    • Robert Koci says:

      Helena: There is simply not enough information here to help you. I think you’ll need to find a contractor in your region to physically look at the house to evaluate the situation and judge whether your idea will work.

    • Richard McPhee says:

      sounds interesting if you are still considering this project let me know and I may be able to have a look at it with you. Thanks Richard

  4. The article states that the air to air heat exchanger was required by the local authorities as a back up heat source but is mostly for show. This statement is completely wrong. The air to air heat exchanger is the equipment that makes this concept work, it is for ventilation and absolutely necessary.

    • Robert Koci says:

      You are right. It was the infloor heating that was installed to satisfy the authorities and was for show. Not sure how that got in there. Thanks for clearing that up.

  5. Adam Balicki says:

    The article states that the HRV has a “A humidity recovery coil”. This would make it an energy recovery ventilator (ERV) not a heat recovery ventilator (HRV). HRVs do not recover any of the latent heat from the moisture in the air, while ERVs do.

    • Steve says:

      Hi Adam,
      The equipment that Reiner used on his project is specialized and isn’t exactly like what’s commonly used here in Canada. He sourced different things from Europe and it’s a little different than what we see here. His project continues to do really well, cost just pocket change to heat each winter month. Do you work anything unusual into the projects you build? What would you like to see us cover more often in CanCon?
      Bye for now,
      Steve

  6. Hans Eich says:

    Just a minor correction. You said “Nothing more than 0.5 air changes per hour (ACH) is considered acceptable”, Passive House requirement is max 0.6 ACH (@ 50 Pa).

    And BTW, foam is almost portrayed as being the be-all and end-all, it certainly isn’t. Plenty of controversy about that. You can build perfectly fine with other products as well.

    • Steve Maxwell says:

      Hi Hans,

      Thanks for your note. That 0.5 ACH came from Reiner and my research with Active House, but it might be 0.6.

      You mentioned that it’s possible to build “perfectly fine” with other products and I agree that it’s possible to build comfortable homes without any foam at all. But from everything I’ve seen, foam is the only way to build an optimal home.

      Tests by various research organizations (like the Oak Ridge National Lab for instance) show that conventional fiber insulations have much lower real-world R values in cold weather than their stated values. This is caused by internal convection currents that cause effective R values to drop with lower temperatures.

      Perhaps I’m missing something, though. I’d like to learn about non-foam options that work as well as foam when a client is looking for ultimate performance.

      Thanks for your help,

      Steve

      • Hans says:

        Hi Steve,

        first of, I have huge respect for what you do, I’ve watched many of your videos and knew of your work long before this discussion here.

        In my opinion, foam offers a very quick and easy way to build high r-value walls, but it appears to have a bad track record for longevity of the building, embedded energy and depending in which foams, maybe even bad effects on health.

        I don’t want to highjack this post here, but would welcome an open discussion with you. I’ve got some alternative systems that I think you’d find very interesting.

  7. Steve Maxwell says:

    Hi Hans,
    Thanks very much for your kind words. I’d love to learn about alternative systems. Learning from others is the main way I get alerted to new and better ways to do things. Would you like to fill me in here, or by email?
    Take care, Hans!
    Steve

  8. Eva says:

    Hi Steve,
    I’m thinking of building a passive house in Ontario north.
    I already have a passive house plan, which is instructed to be insulated by foam, however I’ve been researching SIP and I’m confused which is better option. Is it good idea to switch from foam to SIP system. I am also worried about bureaucratic challenges.
    Thanks

  9. Hans Eich says:

    Hi Eva,

    Many SIPs that we use here, use foam as well. A SIP would just be a prefab’ed wall unit with structural integrity. Are you looking at SIPs that don’t use foam?

    The following is my opinion: if I have to chose the lesser of two evil (I’m going to get a lot of flack for saying that), I would pick foam that is made in a controlled factory environment, and not the one made on site (read: spray foam). Spray foam may have its place in certain retrofit applications, but for new builds I’d always use factory made foam, (to reduce off-gassing, and possible dilemmas from wrongfully installing it. It also loses some of its effectiveness over time and may not be 100% airtight over its life)

    • Eva says:

      Thank you Hans,
      yes, that’s exactly what i meant spray foam vs perfab SIP

      • Steve says:

        Hi Eva,

        I’ve built with SIPs (7/16″ OSB sandwiching expanded polystyrene foam in between) and spray foam applied to stud frame construction, and there’s no comparison. The SIPs are faster to build with, they have much less thermal bridging, they’re easier to build for low air infiltration and they yield a substantially stronger structure than studs.

        Spray foam is great in many applications, but I’m not aware of any better way to make walls, gables and even roofs than with SIPs.

        These are my experiences for whatever they’re worth.

        Take care,

        Steve

  10. Nick says:

    As a concrete contractor and architectural draftsman who has spent 40+ years on construction sites, I’m thinking that if you need a 5% – 10% larger budget for this construction compared to more conventional work, the initial cost of the project would have to achieve a critical mass before this would be true. That is, I doubt you could get these results by spending $15,000.00 – $30,000.00 more on a $300,000.00 house. The extra labour and materials described in this project are expensive. Conversely, the higher the initial cost of the project, the lower the percentage additional costs would be…..you may be able to do the same treatment to a $5,000,000.00 house for an increase in cost of just 2%…….a not insignificant sum of $100,00.00.
    This article needs to have numbers attached to it to be able to be considered as having any value to anybody, other than a good read. What was the total cost of construction? How much more did the Passive House component cost?
    I am happy for Mr. Hoyer, as he has obviously built a super energy efficient house of outstanding quality, something he can be very proud of.
    I was attracted to this article because I plan on building a 1400 sq. ft. one level slab on grade retirement house, using Passive House principles. Super-insulated, with a Steffes ETS unit to keep the slab warm (not the house) and a ductless mini-split to heat and cool the house, heating costs will be similar to geothermal, at 30% of the installation cost. Provided of course that we use the power utility’s time of day usage rates.
    Mr. Hoyer’s house is marginally less costly to heat than mine will be, and is far less dependent on electricity, but I believe the cost to arrive at this point would put the cost recovery period many generations down the road.
    My goal is to build for $150.00 per sq. ft. Allowing for a 5% – 10% increase over conventional costs may allow me to achieve my goal, but I wont be able to use the methods Mr. Hoyer used.
    This country desperately needs somebody to promote Passive House principals in a big way, maybe even legislate it, but solutions need to be affordable for average house owners. Indeed, they already are affordable for average house owners, but if I was to use Mr. Hoyer’s project as an example all arguments would be lost.

    • Hans Eich says:

      Hi Nick,

      I agree that we need to promote Passive House a lot more here in Canada. CanPHI (Canadian Passive House Institute) and Passive Buildings Canada do their best to promote the standard.

      You are correct that we need more numbers. To this day, there are very few good projects with real numbers for comparison.

      What I see as the main challenges are a drastically different construction culture than in Europe where the standard comes from and of course: cheap energy. Pair this with prescriptive codes that to this day did not encourage efficient construction and you have many builders that just build to minimum code that squeeze the last dime out of their projects, to the disadvantage of the long term owners of these buildings.

      There are quite a few certified PH designers/consultants in Canada now, and they should be able to very clearly lay out how the extra cost are justified by future energy savings (BTW, these house are also very comfortable, which is the main driver for it). The designers certified by PHI (Passive House Institute) – I can only speak for PHI since that’s the only exam I took – had a large economic section that they needed to pass on the exam, which should have given them to tools to layout the economies of PH to a builder.

      Nick, if you want you can get in touch with me 905-321-3905 if you ever need any help with PH. I started dealing with some components required for long lasting and energy efficient construction, because I also recognized a lack of support for these kind of standards.

    • Richard McPhee says:

      Nick you should be able to build your retirement home as planned for that price . I have built quite a few passive solar houses and buildings since 1980. Ive been building for the last 15 years using a fully insulated slab of EPS with no frost wall. Just a deepened edge slab on grade with EPS as both form and insulation. Put block or stone or standard frame on top of slab. Give me a call some evening if you would like to discuss. 705-749-3721 Thanks Richard

  11. Steve says:

    Hi Nick,

    Thanks for your note and insights. I’d love to hear what you’ve discovered about building super-efficiently for $150/square foot. You’re right in that we need efficient buildings that are also as affordable as possible. Reiner’s building cost about the same as high-end custom jobs of a regular sort, but that’s still too expensive for most folks.

    I’m all ears and would love to tell your story in my articles.

    You can contact me directly if you want on my main website http://www.realrurallife.com

    Take care, Nick. And thanks again.

    Steve

    • Richard McPhee says:

      I suspect Nick should be able to build for $150 a sq ft as he is a contractor. I built my parents a new 1500 sq ft house insulated slab on grade ( hydronic) Heat source was an inexpensive 33 gallon direct vent hot water heater. All domestic heat and hot water was $36 a month on equal billing ( natural gas) ( gas company changed the meter twice thinking it was broken).That was about 15 years ago and house cost $160,000. Ive built many passive solar buildings since 1980 of heavy and light weight construction with moderate amounts of glass and expansive amounts of glass. Pros and cons to both.I use deepened edge insulated slab on grade whenever I can ( no frost wall just EPS foam). I believe we can build cost effective homes by this method that will compete with conventional. Call me some evening if you want to discuss Thanks Richard
      705-749-3721

  12. Gordon Howell says:

    I find the title of this article to be a bit mis-leading… The use of “no furnace” seems to be just semantics to cause some notoriety… The house **does** have a heating system (look at all the heating technology that he was describing in this article: ETC thermal system, pre-heat air tubes, “HRV provides small amount of back-up heat” and $20 per month in the winter)… **if** the house truly had no “furnace” (i.e., no heating system) then from where does he get his “backup heat” (doesn’t such heat come from a heating system?) and what is causing him to spend $20 per month to heat it?

    I welcome peoples’ comments and discussion.

  13. steve.b says:

    Hello,
    While I read with keen interest, I have to agree with Nick above, without any actual dollar values included in the article, it makes it difficult to digest the fact that Mr. Homer is shown to be a “contractor”. As such is likely paying contractor prices for much of his building products, thus skewing the true costs paid at the contractor level. Typically a discounted value of 10-15% less, so in reality, making his home more suspect at 18-22% higher than a similar “custom” home.
    It makes it un-reachable by most home buyers and this is the true bane of building a net zero home in Canada. Traditional home builders either don’t know, or don’t care about the value they could bring en masse to home owners, in fact they know the average home owner will only stay in a home for 5-7 years, providing a “move-up” model to that same owner as well.
    I’ve chosen Titan Wall Inc in southern AB to supply my entire home in SIP form, importing my own windows and doors from Germany and going with Mitsubishi mini-split ductless system in conjunction with heated concrete floors with interior portico both front and rear of t he home to minimize heat loss upon entry and exit. All while achieving a build cost of $125/sq ft on 1250sq/ft bungalow. I would be remiss if I didn’t say that the pricing needs to be more attractive to all so even home builders get it (wishful thoughts).

  14. Wow, very interesting. I was researching whether I could build in the Victoria, BC, area, with a four foot frost wall, and not have a basement, and put the furnace room in the garage, but I hadn’t even thought of not needing a furnace room… we used to have radiant heat for our basement floor, and any area with ceramic tile… wonder if that whole thing can be side-stepped, out here, where it is very mild, year-round.

    I would love to know more about your process, how hard it really was to get the inspections done… sounds like a lot of hassles, but would be worth it, and a new kind of home for Canadians. : )

    Thanks for the great article, and really informative comments. Ailsa http://www.buildyourownhouse.ca, http://buildyourownhousebodylife.blogspot.com

  15. kabiss says:

    Hello,

    Very interesting project. However, why not use ICF Integrated Concrete Form instead of all the spraying. Everything else from radiant heating to other systems could be used. That’s what we are planning for our construction project.

    thanks,
    /k

  16. Paul says:

    My one level non-basement home is heated with infloor hydronic radiant heat, its an open system with 2 zones. Not too costly to heat the 1100 sq foot space, highest bill for heating in the last 5 years of living their was $135 one month, but it was bitter cold for a couple of weeks. This year has been a pretty good winter for southern Ontario.