Daley Ponderings

Since I'm on a roll of typing out the insulation we've used, I figured I might as well post about our heating systems too.

We have five different heating sources for our home, and someday we'll get a sixth...

1a. Oil burner base board radiators.

I grew up with base board radiators and I always thought they were the best. In college, we had the larger radiators and found those hard to control and were super hot if you were closer to the burner and not hit enough on the upstairs floors (huge house with one zone per floor).  When we bought the house were living in now, it came with an old boiler that was leaking. We had one contractor who said after it got warmed up and wet, the gaskets would seal again, and he was probably right, but by getting a new boiler, we gained efficiency, moved the chimney from the middle of the kitchen and space in the basement.  The new burner also came with a new controller that can adapt its top temperature based on how it is being used dynamically, so when just using the radiant or hot water, it runs at a lower temperature saving fuel. We also put in six zones, though one wasn't necessary (put in on the bad advice of my plumber who should have known better, see the comment in the radiant heat paragraph).

Baseboard heaters circulate the air in order to work, which is surprising to some people because they think it is only about water. But as a friend of mine discovered when he tried to heat his baseboards with his water heater (at 140 degrees, rather than 180 degrees), the lower temperature isn't enough to get the air moving and actually heat the house.  

1b. Oil burner radiant heaters

I say that I used to think baseboards were the best, and they are vastly better over traditional air heat (no hot or cold spots, can't hear it running, doesn't dry the air). Note that geothermal water to air heat pumps work really well, and while they do have air movement, they generally run at lower air temperatures, so you don't get the hot and cold blowing as with traditional air ventilation.  However, any air heating system (including my pellet stove) has a significant problem in that unless you have a mechanical air handling system to heat incoming air using the exhaust air, you have an air/leak problem (or if your house is too air tight, which can happen, you get mold due to the nasty humidity increasing creatures in your house that some call humans). 

You've probably heard advertisements or people say that radiant heat is warmer than other heating methods, so you can leave your thermostat lower. This never made any sense to me because BTUs are BTUs, so how can one heat feel better than another and I'm not convinced that if my feet are warm, the rest of me feels warmer.  But, after using radiant heat for 9 years, I do agree. But my theory isn't because my feet like being warm, but that because the radiant heats the floor, rather than the air, the heat doesn't leave the house as quickly (when we moved in, our house probably had at least 6 air changes per hour, if not more. We didn't measure it until after doing some improvements, where it came in at 4 air changes an hour. I theoretically knew about the ideal air changes an hour and mechanical ventilation, etc, but had never really considered what it meant. My baseboard heaters and pellet stove, dutifully circulating air as part of their operation, were heating air that left the house 15 minutes later. It is kind of staggering when you think about it that way.

So because the radiant pipes heats the floor, and then the air drifts up by convection in its own (and at a lower temperature), colder air is leaving the house, so you waste less fuel.

When we installed the radiant pipes, our contractors and plumbers were worried that the heat might not make it through the thick wooden floors, so we took as much wood off as we could and installed aluminum convection plates on the bottom side of the subfloor, which gets more heat out of the PEX piping than if the piping is just stapled to the floor. Once we turned on the system, it was evident that a lot of heat goes down and was heating the basement and the ceiling of the first floor (which at 10 feet high isn't useful at all), so I installed flexible aluminum sheets that create an air space around the pipe (to hold heat) and direct the heat upwards. I estimate that keeps 75% of the heat from going downwards. I then installed fiberglass under the aluminum to keep the rest of the heat up, and I no longer feel any heat below the pipes. We keep the thermostat around 6 to 8 degrees colder in the radiant rooms than the baseboard heated rooms and they still feel warmer.

The last owner spent $5000 a year in oil, plus an unknown amount on propane. We typically use around two tanks of oil, (360 gallons total, or less than a thousand dollars). Because oil costs are cheaper than wood pellets this year, we'll likely spend more on oil this year than usual.

2. Propane wall mounted air heater

In our apartment over the garage, there is a propane heater that does a decent job, and can heat the room quickly when needed. However, because we don't use that room that much, we leave the thermostat very low but the pilot light uses a gallon of gas every week and when the room is being used, uses around a gallon a day actually heating the room (when we had guests who kept the temperature above 70, they used more fuel than that). An electronic pilot would be nicer to avoid the fuel loss when it isn't being used. We leave the pilot off entirely and then try to remember to turn it on if it gets really cold. We did have the shower pipe freeze and break once, so then we had an electric heater in the bathroom to keep it above 40. However, see the next sections for how the room is heated now.

Because we no longer use that much propane, I was going to get charged an extra rental cost for not filling it as much as they wanted (typical company wants to see 100 gallons a year at a minimum, and the cooking stove only uses 6 or something like that).

3. Pellet stoves

We now have two stoves, one in the living room that I would call our main heat source - we typically leave the baseboards either off or set to 50 degrees. The living room is usually set to 74 degrees during the day and 70 at night. A fan blows the air to other parts of the house. It can burn three bags a day (120 pounds) if going on full blast, which it used to do when the temperature was below zero, but after our air sealing and insulation improvements, it hasn't ever needed to do that, and it typically burns 1.5 bags a day all winter long, adding up to 4-5 tons in a year.

We have a second stove in the garage/shop, which keeps things comfortable (there is some electrical heat tape installed by the previous owner, to keep the apartment from freezing, but I don't think it has been used since we insulated the shop. I keep the thermostat set to 48 normally and increase it to 64 when I'm out there working. It burns a ton of pellets a year. 

4. Air-to-water heat pump

I don't exactly understand the physics of it, but the idea is that because the air temperature in my basement is above absolute zero, it contains energy, and so you can extract that energy and heat my hot water tank. It uses electricity, which in NH is the most expensive way to heat, but because it is a heat pump, it gets "free" energy from the basement and so in the summer is 3 times more efficient than direct electric heat and costs about $6-8 a month to heat our water (120 gallon tank for a family of 8 - see below for the future expansion of yet another heat source). In the winter, it is more expensive to heat with the pump than with oil, so we manually switch over to oil when it gets cold (usually November to March or April).

In addition to being cheaper (and better for the environment, depending on how the electricity is being generated), it also dehumidifies the basement, and so we don't need to run the dehumidifier as much to keep the mildew/musty smells at bay, which saves $20-30 a month during the summer. It does make the basement cooler, but it is nicer in the summer, and I don't run it in the winter, so that works out well.

5. Solar air heaters

I now have 8 wall mounted solar heaters (and have plans for at least 4-6 more). We have excellent southern exposure, and use some really neat homemade heaters that mount on the outside of the wall, and have holes in the top and bottom connecting to the inside and naturally convect cold air from the floor, heat the air (up to an amazing 140 degrees) and exhaust the air at the top. There aren't any fans, but the heat rising blows air out at the top, enough to move a piece of plastic sheeting that covers the top vent (which is necessary to keep the process from reversing itself at night). I improved the design on the internet by adding a double-walled Lexan sheet on the outside, which doesn't look quite as nice and limits the visibility from the inside (with a single wall, you can use them as windows).

There are three of these heaters in the apartment, effectively eliminating all propane costs, except when we have guests and it isn't very sunny. Typically, the temperature is in the 60s during the day and drops to the 50s at night. There is one heater in the stairway going to the apartment, which gets quite hot, often in the seventies and warmer than our nearby kitchen, so we sometimes leave the door open (Hmm, I should install an automatic fan to blow air into the kitchen when it gets warm enough). There are two heaters in the garage, which aren't enough to make it comfortable in the shop, but reduce the amount of pellets I use. Lastly, there are two heaters on our porch, which aren't 100% installed yet (no one way valve, so they cool the porch at night), but I expect to not use any heat in the porch and it should be quite nice; we might open that door to the kitchen and well as appropriate. I've wondered about installing vents from there to the upstairs bedrooms, but haven't done that yet, we'll see how it works out.

6. Solar water heater (later...)

You might have noticed that our water heater is oversized for a typical house and that is because we originally planned on having it heated primarily by the sun using oil as a backup. Our installer died before we were ready to complete the project and once I had the heat pump, it became a lesser priority compared to some other projects, but we'll probably do it eventually and then use the heat pump as a backup and remove the oil entirely.

I'll have to add some pictures to make this post a little more interesting, but that's a good amount of writing for today.