ODYSSEY PART 21 - II: How a solar house is born – Part II

by Lisa Paulson

Q. You designed and built your solar home at High Wind back in the mid-1980s. Can you tell us how that project was developed, both from a technological and philosophical standpoint?

A. Last week I described the process of creating such a home. Here is how it worked out for us.

How passive solar works: The purpose of the concrete and masonry floors is to soak up the sun’s heat by day and release it slowly during the night. If we’ve had several bright days to charge up this “storage battery,” the effects are enjoyed for a period of cloud cover. The low angle of the winter sun penetrates 15 feet into the living room and hits the massive fieldstone hearth where more heat is absorbed.

Woodstoves: Backup for the solar system consists of two woodstoves, a Jotul #8 in the living room and Kent downstairs. On the advice of the seller, these do not have catalytic converters (which are tricky and can break easily); ours do well on “garbage” or soft woods. I should emphasize that for the first 11 years we had no central heating – and (I told people proudly) almost zero fuel bill (we mostly picked up dead wood from our forest). But then Bel and I began to worry about our ability to haul and chop wood as we got older. I researched somewhat environmentally friendly alternatives and came up with the Lenox Complete Heat system – a gas water heater that vents some of the excess heat around the house. It felt almost sinful; I could flip a switch and get almost immediate warmth! Remember, however, that we still needed to resort to propane only when there was a cloudy spell. Just recently (when the Complete Heat failed after many faithful years), we installed a new energy efficient boiler – but again, it’s only used when there’s been no sun for a while. The woodstoves are still employed but less often.

Other energy-saving technologies: Having gone to great lengths to make the house tight to retain the heat, we had to deal with stale, possibly toxic, air – so we installed an air-to-air heat exchanger that makes for five complete air changes in the whole house every hour (using the outgoing, warm stale air to heat the incoming, fresh cold air).

An active solar domestic hot water system provides nearly 100 percent of our hot water when the sun is shining; on cloudy days, it’s now backed up by the boiler.

To protect against further heat loss – from the “glass holes” in the house – the east bedrooms have pocket windows (hollow-core doors cut down) that slide out of the walls to cover the glazing. For years we also used foam board pop-ins.

When we first moved in, we waited to decide on coverings for the large dining and living room windows; we wanted to experience every kind of weather before buying. Actually, we found the need was more to protect ourselves in winter from overheating and glare than from the cold. Especially with the low sun penetrating, we found it difficult to sit comfortably next to the windows – temperatures could shoot up over 85 degrees at Thanksgiving with no back-up heat going. We opted for accordion-pleated blinds that let in a lovely filtered light and stored at the top in only 1½ inches. There is a small R-factor as well when deployed for winter coziness.

There were other energy decisions: We have no dishwasher. Until last year we had no clothes dryer (succumbed to a dryer when our 30-year-old washer quit, but still hang out 95 percent of the time).

Coming out of our 24th year here, I continue to be amazed at how we have to strip down to T-shirts when the sun blazes through our Heat Mirror windows, even in the coldest weather. One of the really satisfying things about living in a passive solar house is looking out at mountains of snow glinting under a brilliant sky; it may be February and below zero out there, but in my living room it’s 80 degrees. It’s also satisfying to know that I’m not using any wood or propane backup. I won’t have to light fires later, either, because heat is being stored in the slate floors and hearthstones, and will slowly release during the night. There are no fans or machines to make this happen; the house just sits there and performs its silent magic. And it’s gorgeous!

Living in Hawthorne House has been extraordinarily pleasant from nearly every standpoint. I enjoy the opportunity to be sensitive to what’s happening outside, fine-tuning the building to work with the natural elements that allow it to take its place among them. And I like sharing information about the house with frequent visitors; High Wind is always on the annual National Solar Homes Tour.

As I said at the beginning, our house was cutting-edge when we built it, but now the advances have galloped way past our modest, pioneering (and relatively cheap to build) experiment. Though we’ve saved a huge amount on fuel bills, there still is some cost (especially now that we’ve “given in” to a conventional, though very efficient, boiler).

I invite you to check again The Review column of March 23, “Net Zero Energy House Possible.” Our next-door neighbor, David Lagerman, discusses their combining two very efficient approaches: a “high mass” system that, with exterior active solar panels, stores heat in 2 feet of sand under the house foundation; and a “downsized geothermal” system that takes heat from the ground in winter, concentrates it and delivers the heat indoors (in summer, working in reverse, heat is pumped out of the house and dumped underground). Installation and operating costs are not trivial, but the outlay may be justified compared to the energy required to run conventional systems.

I’ll end with a favorite quote from Christopher Alexander: [There is] “a fundamental view of the world; when you build a thing you cannot merely build that thing in isolation, but must also repair the world around it, and within it, so that the larger world at that one place becomes more coherent and more whole, and the thing that you make takes its place in the web of nature, as you make it.”

We did our best to follow this guideline in the adventure of building our house.