The Sun House

I took a tour of the home of Frank and Liz Barningham’s off grid “Sun House” on the weekend near Durham. I learned a lot.

It was about -6 C and sunny outside. Inside was a comfortable 21 C, with no heating system operating. They had put on a small woodstove fire early in the morning to bring the temperature up, but it was no longer burning.

The walls are made of a double thickness of sand filled cinder blocks, which inside were covered in a sort of plaster or stucco, that was very pleasing to look at. Between the cinder blocks are two layers of insulation – some foam pieces, followed by 2 X 4 construction with more insulation. The walls are R40. The ceiling is R50, with blown insulation. The floor was coloured concrete, with some strategically placed rugs. Underneath the floor was more insulation. There are no thermal bridges from outside to inside – every inside material is separated from the outside by insulation or air. This is a key part of building an efficient house. The mass of the cinder block and sand, the concrete floor, even the stucco, gives the house a lot of thermal mass. That means it changes temperature only very slowly, retaining its heat or its cool, buffering it from the outside temperature swings. This is another very important design consideration.
The windows are triple glazed with fiberglass frames. I asked if they were hard to find, and Frank said they are widely available.

On the front of the house, mounted vertically on the walls, are ten 85 W BP solar panels. The vertical mounting keeps them clear of snow, and maximizes the solar gain from reflection off the snow. Each panel then feeds by its own wire to the control center and batteries. When the batteries are full, the panels just stop generating. Some systems have a “dump load” – basically a resistance heater – to use surplus energy, but this system doesn’t require it.
The house was run almost entirely on 12 V appliances and lights. Frank has a good collection of rechargeable appliances with their own batteries which are charged off of the system. It included a battery powered vacuum cleaner, which runs for 25 minutes without a charge. The lights, water pump, fan, refrigerator are all 12 V. The refrigerator is kept in an unheated part of the house, so of course in the winter, it uses almost no power. It is top loaded, so when it is opened, the heavy cold air does not escape. There is one 120 V appliance – the washing machine. Liz used an inverter to boost the voltage to 120 V to run this. Liz does laundry on sunny days, and of course uses a drying rack, or clothesline, not a dryer.

Frank is always trying out new things. One of the newest he had was a reading light that uses an LED, and consumes only 3 W. It wouldn’t take much sun to run that!

The home was extremely comfortable, with lots of natural light, and a real inviting character. The eaves are wide enough to allow the sun to shine inside during the winter, but to provide shade during the summer. The front of the house, and most of the windows, were on the south side.

Hot water and cooking are done on a wood stove. The wood stove has a 2 litre stainless steel cavity, that the water heats in, and it is circulated by convection to a 60 gallon hot water tank. The Barningham’s are retired, so taking a bit longer to cook on a wood stove is a pleasurable part of the day for Frank. A working couple might need to consider solar hot water, and some low power appliances to supplement the wood stove.

The Barningham’s do not get a bill from Hydro One. The original installation of the power line to the home would have cost more than $12,000, so of course they saved that. They use about 15 face cords of wood a year, which would cost about $1000. The buy no oil, no propane, and no natural gas. And their home would be as close to carbon neutral as you can get. They have no backup gasoline generator. It turns out the sun is more reliable than a generator is – they have never run out out of power.
Congratulations on your foresight Frank and Liz. You are showing the way. And if I was building a new home, I would certainly use many of the design principles you have implemented. This is not a “home of the future”. It is a home of today.

Leave a Reply