Along with its unprecedented achievements, the Kenogami House continues to act as a laboratory for resilient, cold climate building practices. Through software energy modeling it was determined that the Kenogami House would likely require 14.6 kWh of heat per square metre per year, but its actual performance seems to be even better.
What we have learned this first winter is that 4 hours of heat captured from the sun can provide approximately two days of comfort. Regardless of outdoor Celsius temperatures in the minus twenties and no supplementary heat, with a day of full sun the Kenogami House has achieved interior temperatures as high as 26.9 °C (80.5 ºF), a temperature where many people will have already turned on their air conditioners.
During average winter conditions of temperature and cloud coverage for the Saguenay region of Quebec, the Kenogami House had its heating system turned off for a 10 day stretch in February, yet maintained indoor temperatures in the mid 20s (°C) and dropped only to 20.4 °C after consecutive overcast days.
To balance temperatures through the home, unheated water is pumped through the concrete slab floor to help transfer the warmth of the sun from the southern exposure to the north end of the house, also making sure rooms exposed to the sun do not overheat.
The following table charts the temperatures over the course of a 4 day period with variable temperatures and sun exposure.
|Date||Time||Ext. Temp °C||Int. Temp °C||Slab °C|
|Feb 17 (full sun)||8:00 AM||-20.9||22.2||19.5|
|Feb 18 (mix of sun &cloud)||7:00 AM||-24||22.6||20|
|Feb 19 (80% overcast)||6:30 AM||-3.1||20.8||19|
|Feb 20||6:00 AM||-12.3||20.4||18.5|
While Ecohome's Passive Solar Index program (PSI) of energy modelling designs from the benchmark of complete passive solar heating, this is not a rigid target. Depending on climate and other considerations (such as with the Kenogami House), achieving zero heat demand is not always the best use of resources.
Regardless of your building envelope, in terms of resiliency we would always recommend an additional heat source to ensure comfort in even prolonged overcast conditions.
However, at levels of thermal performance like that of the Kenogami House, a centrally located single heater of approximately 2100 w (similar to a powerful hairdryer) would likely be more than sufficient during the most extreme cold, and for the most part not be used at all.
The building envelope:
- 91% of glazing is south facing
- Triple paned argon filled fiberglass framed windows > R4.5
- Ceiling: 3" Polyisocyanurate and 36" of cellulose > R151
- Wall insulation: 14" of EPS foam and 7.5" of mineral wool > R 80
- Slab on grade insulation: EPS foam and polyurethane > R60
- 0,57 ACH @ 50 Pa ( Air Changes per Hour at 50 Pascals of pressure)
- 5400 w photovoltaic solar panels with battery backup
- Radiant floor heat powered by a high efficiency gas boiler
- 84% efficient Zehnder Novus 300 ERV (Energy Recovery Ventilator)
While similar in concept, an ERV (Energy Recovery Ventilator) was chosen over an HRV (Heat Recovery Ventilator), as they are particularly well suited to extreme northern climates.
Air is able to support less and less water vapour the colder it gets, and an ERV extracts that energy rich moisture from interior exhaust air before it is ejected. This helps keep indoor humidity at more comfortable levels, along with retaining the added heat energy (known as 'latent heat' that is contained in vapour compared to dry air.
The ERV system will continue to offer energy savings in summer months, as removing moisture from exterior air before it is injected into the home makes high temperatures more bearable, while also reducing the load on air conditioning systems. In this case, the ERV in conjunction with the high R value building envelope and passive cooling design will likely make air conditioning unnecessary except in extended heat waves with high night time humidity levels.
Life in the Kenogami House
As homeowner and part of the Ecohome design team, Alain Hamel will continue to experiment with the latest energy systems to further enhance the performance and thermal comfort of his home. The next system to be installed will be an air-to-water heat pump which will serve as an air conditioner. In effect this will prevent the home from overheating during consecutive sunny days in winter, while producing hot water essentially for free.
Heat extracted from indoor air will be transferred to the existing hot water tank, allowing excess daytime heat to be used for domestic hot water use or released into the slab floor to balance temperatures through the night.
Being considered for the future is the addition of a phase change thermal battery that will work in conjunction with the air-to-water heat pump, which can store approximately 10 times the heat by volume as water.
As this home was designed for resiliency, among other notable features it includes an underground 2000 gallon rainwater harvesting system which feeds showers and toilets during all seasons, being charged in winter by melt runoff on warm days.
Durable, low maintenance design:
The true cost of a home can only be determined when factoring in its expected lifespan and the maintenance that will be required along the way. To that end, both interior and exterior surfaces have been designed to endure. The polished concrete floors will require little maintenance, as will exterior surfaces of metal, stone and cedar.
The goal during the design of this home was to make it as durable, efficient and autonomous as possible. Many of the design features are original, and these technologies very new to the market. It is for these reasons that we consider the Kenogami House a living laboratory of resilient building technologies that will continue to be fine tuned, and hopefully offer insight and inspiration to others.
How much would a house like this cost? In Saskatchewan
There are a lot of factors to consider, but our best overall guess is that it takes somewhere around 10-15% more on the total building cost to super-insulate your home so you need practically nothing in the way of heat generation. In this case it took approximately $30,000 extra. In most cases, the added annual cost on a twenty five year mortgage ends up being around the same amount you would have been paying for heat every winter, so it can actually cost you the same and sometimes even less per month than had you build a house just to meet code.
Sounds an awful lot like a Passive House; give credit where credit is due.....?
Hi, thanks for the comment. I think yours might be a common thought, where a brand name starts to take on meaning for a concept or product, such as 'Kleenex' or 'Windsurfer' for example.
Passive heating and cooling as a concept is not new, it dates back thousands of years. 'Passive House' is a recent North American adaptation of 'Passivhaus', a 25 year old German building rating system which itself was inspired by a 37 year old house in Saskatchewan called the Conservation House.
The Net Zero Heat program is a design service and challenge where we acknowledge homes that match or beat the performance of the Conservation House, so if you read our Net Zero Heat pages I think you will find we have given credit where it is due.
The design philosophy of passive heating and cooling took far too long a break until it was revived by a group of Canadian designers led by Harold Orr.
We did consider Passive House certification for this project, but in the end found it wasn't in our interest. So implying involvement with the Passive House brand wouldn't be fair to them, nor have we paid for that privilege. And the Passive House Institute didn't contribute to this project so it also wouldn't be fair to our design team.
That said, I highly recommend reading Harold Orr's own reflections on his passive house design that changed the construction industry. What his team did for cold climate housing is similar to what the Wright brothers did for aviation. These were pioneers that brought us the HRV, the blower door test, and arguably the 'air barrier'. No amount of credit given to them seems enough. Best regards.
Sounds great, how soon until you are building and selling them in Victoria, B.C.?
All we do from out end is building envelope optimization, building it is up to you. This first one was built by Alain Hamel of Ecohome, but only because it was his own. But location does not impact at all our ability to set you on the right course.
If you are looking at building your own home, send us your plans and we run them through software energy modelling programs along with your specific climate data (temperatures / sun hours) to find out what your ideal building envelope is for your location.
Keep in mind, the Net Zero Heat program is not an 'all or nothing' deal, we help you find where the weakest parts of your thermal envelope are in order to give you a chance to redesign. In the absence of energy modelling such as this it often ends up being the case that we over insulate in some areas and under insulate others. NZH is about adjusting that so you get the most bang for your insulation buck. Drop me a line if you want more info. [email protected]
Congratulations! It is a wonderful design.