Keeping Warm for (Almost) Free

Keeping Warm for (Almost) Free

October 19, 2008


While riding back from a kayaking trip with a friend this weekend, we were talking about people’s apparent inability to act in their best interests when it comes to home heating. Up here in chilly upstate New York, many people who really can’t afford it will spend $800 or more per month for heat. Indeed, I’ve heard that in our former upscale Connecticut suburb (in a milder climate), it was common to use about one gallon of heating oil per year per square foot. For 2500sf, that’s 2500 gallons * $4.00 (or whatever the price of heating oil is), or $10,000, working out to perhaps $2000 per month in winter plus a little for heating water. I don’t know if people understand how much 2,500 gallons is. It would power the Loremo automobile for 355,000 miles. I suspect nobody intends to use this much fuel, it just sort of happens. You make some money and decide to move somewhere with good schools, which tends to require a certain sort of house. The house comes with the standard central heating unit. You turn up the thermomstat to a cushy 70F (after all we aren’t penny pinchers) and then the big bills come. You try turning the thermostat down to 67F, and notice its quite a bit cooler and somewhat uncomfortable, but the bills are almost unchanged. What other option is there?

People just don’t know how to do it, or even that there is a choice, and that changes in behavior produce results. It takes a certain attention to throw out the old system and apply a new one. While in college, I spent several New Hampshire winters around a woodstove. Not only was this good fun, it was almost free.In those days, we paid about $125 per cord for wood. There were four of us living in the house. We burned three cords of wood in the winter. That’s 3x$125 or $375, or about $100 per person for a whole winter’s worth of heat. This was no great hardship — indeed, it was the centerpiece of many fond memories.

Today, I don’t have a woodstove. My 3000sf factory loft conversion is heated entirely with electricity, normally the most expensive means of heating. I mentioned last year that our main strategy, in this regard, was to simply leave most of the space (about 2350sf) unheated. We have a 500 sf “winter apartment” with insulated interior walls, and a 150sf office space.

This year, we’re tweaking our techniques to get our heating needs to about $100 per month, even with expensive electric heat. I’ve mentioned it before, but I feel that I have a duty to establish some precedent in these matters, and explain how to produce results.

1) Additional R-38 insulation above the “winter apartment.” There is already about R-26 in this space, so the total is raised to R-64 or so. That is not too much … I would probably go with an additional layer of R-38 (12″ of fiberglass insulation) in the future. Cost: $380.

2) “Kotatsu desk.” The office space is nearly unheatable. With 12′ ceilings and 9′ factory windows (facing north), it’s practically all glass. Double-pane glass has an R-value of 2. Last year, the solution was to turn off the baseboard space heater, which was locked into an eternal deathmatch with the window/space cooler, and use an 800W under-the-desk radiant heater. This worked just fine. Most of the time it was on the 400W setting. This year, a “kotatsu desk” is made by covering the desk with an old bed comforter, which hangs down to the floor. A piece of plywood is placed on top, to give a desk surface. The 800W heater is replaced by a 250W radiant infrared light bulb (the sort that keeps the roast beef warm at the Sunday brunch). I’m expecting good results from this. Just for pure overkill, I lined the underside of the desk with foam/foil insulation. Cost: $100 (plywood and light fixtures)

Wikipedia on “Kotatsu”

3) Pipe insulation. Last year, we had to keep one of the large “living rooms” at 40F to keep a water supply pipe from freezing. This year, we wrapped it in foam insulation and applied an electric pipe heater tape. The tape uses about 500W to heat 55 feet of pipe. There’s a thermostat so that the pipe tape heater is only on when it is quite cold. I have this on a separate electric meter which will measure how much power is used. It has been about 20F in the mornings here, but it hasn’t turned on yet. I’ll be intrigued to see how it does at minus 10F. I think it will hardly ever come on. Cost: $100 (heater tape and foam insulation).

4) Making windows disappear. Windows are huge heat losers. Double-paning doesn’t do all that much, going from about R-1 to R-2. The double paned, argon gas-filled windows do about R-4. The highest-tech triple-paned krypton gas-filled windows do R-10, and cost a couple fortunes. We have some windows that are not really useful. For example, there are large windows in the laundry room, which needs to be heated due to the plumbing. This room is really a utility room that is used for a couple hours a week. The windows will be filled in with 2″ rigid foam/foil insulation, cut to fit the window frame. This has an R-value of 10, and of course has the additional benefits of a radiant heat barrier. The bathroom will have 50% of windows filled, and there are some interior windows and sliding glass doors that will be filled in. Of course, all of this is removed in warmer weather. Besides, it’s dark most of the time in winter! I once talked to an Alaskan, up near the Arctic circle, whose bedroom had no windows. “In winter, you don’t need it, and in summer, you don’t want it,” he said. Total cost: 5 sheets (4’x8′) @ $32 each = $160.

5) Insulated curtains. Covers remaining windows at night, which is about 14 hours a day in winter. Cost: about $150.

6) Thermal paint. Recently, there have appeared “thermal paint” solutions which use reflective microspheres. This can be mixed with regular paint, and is about 90% reflective of infrared. Like aluminum foil, but it looks like regular paint. Some people have reported reductions in heating expenses of 30% or so by using these products. Cost: $60 for five gallons worth of microspheres, and $30 for two gallons of paint, plus some materials = $100.

Thermal paint additives from Hytech

Total cost: $840. Savings in typical winter: about $800. Return on capital: 95%. Probably my best investment idea this year.

My preliminary budgeting is:

“Kotatsu desk” heater 250W @ 12 hours/day (for two desks): 3.0 kwh/day. 90 kwh/month@$0.15 = $13.50

Minimal space heating: 1000W plug-in heater with thermostat set at 42F: 4 hours/day = 4.0kwh. 120kwh/month@$0.15 = $18

Additional space heating: 800W radiant heater. 6 hours/day @ 800W = 4.8 kwh/day. 144kwh/month@$0.15 = $21.60.

Pipe heater tape: 500W @ 2 hours/day. 1.0 kwh/day. 30 kwh/month@$0.15 = $4.50.

Total for heat: $57.60/month

I’m leaving some margin for error in my $100/month budgeting. I’ll let you know how it worked out. Everything is on separate electric meters, so I’ll be able to see exactly what’s going on.

Buy a Kill A Watt electric meter from

In practice, with our big south-facing windows, if the “winter apartment” is adequately insulated, we might be able to have no heating at all when the sun is shining. Also, at night, ambient heat generation (refrigerator, people, pets, water heater, thermal mass etc.) seems to keep things quite warm. Early last morning, for example, it was 20F outside and about 63F inside, with no heating whatsoever, and without the sun shining (and without a lot of things that haven’t been installed yet, like the curtains, foam/foil and thermal paint). If I can maintain a 43F degree thermal difference, without that stuff, then I should manage a 55F degree difference with it. That would mean outside temperatures of minus 13F before the backup heater kicked in at 42F. So, it’s possible that my estimates will be too high. If all this stuff works really well, I’ll be pretty close to kicking the heating habit altogether — with things kept around 45-55F at night from ambient heat, and 70F during the day from sunlight.

Observe, also, that all of this is quite cheap and simple. It is high tech (silicon microspheres and foam/foil insulation), but it does not involve big, expensive, complex contraptions. I haven’t mentioned solar hot water collectors ($12,000+), ground-source heat pumps ($25,000+), huge rewindowing projects ($15,000+), gutting and rebuilding exterior walls with more insulation ($50,000+), passive solar greenhouses ($20,000+), wood pellet furnaces ($3,000+) or all the other Green Baloney that seems to grab people’s attention these days. All of it, added together, won’t produce the results ($60/month bills) that I expect. Of course there are plenty of people ready to sell you tens or hundreds of thousands of dollars of new gadgets. Nobody’s going to sell you on an $8 infrared light bulb. A lot of this amounts to expensive, marginal improvements on existing systems which are inherently flawed. You get a lot more benefit from dumping the old system (central heat), and adopting a new one (kotatsu desk).

* * *

I’ve also set up a little “micro-solar” power system. It consists of:

1) Twelve watt (one amp) “briefcase” style solar panel. I paid about $100, but you can get one for $70 now. A slightly better solution would be a Sunforce 15 watt panel ($99.99 at

2) Xantrex Powerpack 400. This is a portable unit that contains a 20Ah SLA battery, 400 watt inverter, 12V outlet, and an AC charger. (It also has a light, and, bizarrely, an air compressor.) The solar panel can be connected to the AC charger port, or using a charge controller. $109.

3) Sunforce 7 amp charge controller. $24.99.

So, for $235, I have a battery backup that can be charged from wall power, solar, or even a car 12V port. 20Ah is not a whole lot, as that translates into 20*12 = 240 watt/hours or really 120 watt/hours usable. Nevertheless, that is enough for a few LED lights, a notebook computer, and my DSL modem/router. That’s really all I need electricity for, at a minimal level. I’ve established independence from the electrical grid, if the grid becomes unreliable. Plus, I can carry the whole thing, with the Xantrex in one hand and the solar panel in the other. I could use a car battery in a pinch. Once again, this solution is vastly cheaper, simpler, and more reliable than sinking $35,000 into a big solar system, with a roomful of batteries.

* * *

The “GlobalEurope Anticipation Bulletin,” a doomster-ish financial publication with a prescient track record, now says U.S. federal debt default and high/hyper-inflation by summer 2009. Funny, the webbot project ( says exactly the same thing. Generally speaking, it is quite unrewarding to make such doomy predictions. So, I won’t. But, I am prepared for hyperinflation, if it happened, and also prepared if it didn’t. If it did happen, I would say: “Well, there you go. It was so obvious.”

GEAB 20/20 latest report