Gravity furnace in old house (1910). Heat has been off for 2-years. Functional up to that point. One of the big octopus elbows has been knocked off. What kind of efficiency can be expected with this type of converted coal furnace?
Low on cash and trying to make a house habitable. In upstate New York are. Natural gas fired.
How exactly is this for heating? Does it work okay, I’d prefer not to have to update system at this time.
Thanks!
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My past experience with a converted coal gravity furnace. Good heat at closest register, poor heat (unless straight up to upper room) on remote or second story rooms. Need ceiling fans to move the air around, registers were located away from outside walls. On very cold days, we would lay a box fan flat over the large register to help out the flow. I think the biggest problem was in the conversion. A constant coal fire I think burned hotter than the nat. gas conversion.
Be careful with relighting or messing with it if pilot goes out. I managed to blow the door off, lucky my head is still on my shoulders.
Remodeling Contractor just outside the Glass City.
Quittin' Time
"low on cash"
I'll bet your 1910 house has no insulation too. If you do not update NOW, it may cost you more for the year!!!
Brother and I are in process (mostly brother, I put in a heat pump and new elec service, then left town<G>) of upgrading Grandpa/Grandmas old house, built in 1907.
I distinctly recall paying grandma's gas bill for the NG coal conversion in 1974 when NG was around 6 cents/therm and the gas bill was $30 (a lot of $$ for me then) in centrl IL, so at $1.00 or so a therm now you can probably look at a $400 month gas bill for heating if you try to use the old coal conversion monster - talk about short of cash. Reverse calcualtions put the efficiency at near zero for the combo of 20% or so combustion efficiency and no insulation.
First put your money into the cheapest insulation you can find for the first layer on attic floor (ceiling, and much more as your cash flow improves) and a few rolls of masking tape around windows to get you thru the first winter in sweaters. Tape up any cracks in the plaster also, keep a trow rug rolled up at the bottom of all doors. A lot of wadded up newspaper can seal up bigger cracks short term.
Assuming you are competent DIY, and if you have at least $1500 or so cash at all available, then go to a web site or ebay and buy a packaged heat pump (you can DIY that install totally yourself) and a plenum and a few boxes of flex duct from a big box store. Simply mount the packaged heat pump on a couple of leveled pressure treated 4x4s with a sheet of poly over for the first year, bash a hole in the wall, run in the plenum and route a few flex ducts. Get some Taunton and other publishers books from the library on HVAC and wiring for guidance, dont buy when the library is available - most if not all can get all the Taunton and other books on interlibrary loan if they do not have them themselves.
The attachment is for a trade for a heat pump vs 80% NG furnace, I got a scratch and dent packaged 3T HP off the net for $800 (Desco/ebay to be specific), and got $400 rebate from the power company for installing a heat pump - rebate based on typical retail price vs. scratch and dent unit!! . Remember, with what you got now the Jan bill would be $500 vs $125 in the figure for a 80% NG furnace. (80%/20% = 4 times the bill ) .
Blew the first attachment, wanted to add only a graph, but you can use the whole spreadsheet and convet to your weather if you wish. New attachment follows.
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Edited 8/22/2005 7:13 pm ET by junkhound
Edited 8/22/2005 7:18 pm ET by junkhound
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We owned a gravity-fed hot-air furnace, also converted coal, in a bungalow in the Finger Lakes region about 20 years ago. The heat came on slowly and we weren't especially comfortable until we got the place insulated, but it was a small, one-story house. These days, I would want something more efficient. Using fans to move the warm air around is good advice.
Have someone who knows what they're looking at check to see if the furnace is safe, because we had a couple of close calls when the pilot light went out, too.
We've also had a heat pump and didn't like it on really cold days. We were below the Mason-Dixon line by then (but not far below it -- there was still winter) and when it was below freezing, we found the heat pump didn't produce the warmth that real radiators or forced hot air did. (We could go a week without feeling warm.) Heat pump technology might have improved, and it is certainly better than your current furnace, but see if anyone you know is using a heat pump and is happy with it on cold winter days.
One more possible problem -- our old gravity-fed hot air pipes had accumulated a lot of junk in the pipes. Even though we cleaned them out, the system still had an ugly smell at random times (worst at the beginning of the heating season).