Heat pump + Oil + Coal?

Heat pump + Oil + Coal?

PostBy: gwgjr34 On: Sat Oct 11, 2008 10:11 am

So, I have two used coal boilers sitting in my basement, but I'm not sure if I should install them. I purchased a new house last spring. It's a large home with a hydronic 6 zone system. When I purchased the home, I did not realize that the 5 outdoor condensing units were heat pumps. I thought they were AC units as they were labeled in the breaker boxes. Because I thought they were AC only, I left them turned off over the winter. I didn't realize that they were heat pumps until last week, when we turned the heat on for the first time this year. Instead, I ran the oil boiler from Jan until April and burned approximately 1500 gallons during that time.

In an effort to move away from oil, I purchased two used coal boilers this fall. The first was a Tarm 202 (80K BTU). I knew it was small for my house, but I purchased it because boilers of any kind appeared to be in short supply. I purchased it with the intent of selling it if I could find a larger unit before the winter. Then, last week, I found a Tarm 303 (120K BTU) which I purchased. The night I got the 303 home was the night that I discovered the heat pumps. So, now I'm trying to decided if I should install a coal boiler at all, and if so, how it should be installed. My electricity runs about 14c/KWh. It seems that I could install the coal in series with the oil, but only fire it up when the outdoor temp is below 35 degrees. That means that I would have to turn off the heat pump and then fire the coal boiler every time I want to make that transition. with falling oil prices, this would significantly extend my payback period.

Anyways, that's my long winded story, but I'm looking for suggestions on what I should do.

Thanks!
Gary
gwgjr34
 

Re: Heat pump + Oil + Coal?

PostBy: dtzackus On: Sun Oct 12, 2008 9:13 am

Gary,

I have a heat pump / a.c. combination unit that is a 13 seer unit. The higher the seer number, the more efficient the unit. Heat pumps are only efficient up to about 40 Degrees. Below 40 degrees they cannot "stuck" the warm air anymore and then proceed to turn on their electric heat furance which will cause your electric meter to spin like crazy. Also, the other problem with the heat pump's heat is that is isn't a very "hot" heat, only maybe ever reaching 80 degrees, it isn't pushing the Btus of fossil fuel heats.

We have a upstairs propane gas fireplace and until this past month a gas heater downstairs. The upstairs gas fireplace is nice but since I live in the "sticks" I cannot connect to city gas and I can only get 100 pounds tanks. And 100 pounds tanks do not last very long. The downstairs gas heater was a joke, it wasn't worth the metal it was made out of. I went with a hand fired coal stove, a Gibraltar LCC model. I have turned in on a few days ago when the temps got below 40 at night and I could not believe how warm it kept the entire house, 85 in the rec room in the basement where the unit is and 80 degrees upstairs. I know I turned it on way to early, but like a kid with any new toy, I had to play with it.

Long story short, I would keep the heat pump on until the nights get colder than 40 after that, burn the coal!

Dan
dtzackus
 
Hand Fed Coal Stove: Gibraltar LCC
Stove/Furnace Make: Gibraltar
Stove/Furnace Model: LCC

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