Thermo pride furnace
#1
Member
Thread Starter
Join Date: Oct 2007
Location: S. Central WI
Posts: 11
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Thermo pride furnace
Anyone know what the approximate efficiency rating would be on a 30 yr. old Thermo pride oil furnace. It works great, and has been serviced annually since new. Just wondering about replacing it with a natural gas furnace, if it would be worth the expense. I don't really want to replace it, you know the old adage " if it aint broke don't fix it". Thanks for any input.
-Tom
-Tom
#4
Ummm. I'd guess around 70%. The limitation on efficiency for old gas furnaces is the need to keep combustion gasses hot so they will rise through the chimney and prevent them from condesing moisture into water in the vent and chimney system.
I'm guessing that the constraints would be similar for oil.
New high efficiency gas furnaces are 90-92% efficient. They use a motor to force combustion products through the furnace and venting system, and are designed to condense the water vapor produced when burning gas into water. That allows the combustion products to be vented out using PVC pipe at temperatures of around 120 degrees, plus you recover the latent heat produced when condensing steam into water.
A gas furnace sized for a house may produce a gallon of condesate per hour if running continuously. People have an intuitive idea of how much heat it takes to boil a gallon of water away ---- if you convert the water vapor into water, you get about that much usable heat in the process.
So the 90%+ efficiency level is real.
Seattle Pioneer
#7
Join Date: Jan 2005
Location: Delaware, The First State
Posts: 12,682
Received 41 Upvotes
on
39 Posts
Thermo-Pride
At 30 years old, you are likely running in the 75-80% efficienct range. Thermo-Pride makes the finest oil fired furnace on the market. Just out of curiosity, what burner was Thermo-Pride using then? My guess is either a Beckett AF or SR.
If your furnace is typical, it is probably grossly oversized for the house. The best $50 you could spend would be at http://hvaccomputer.com for use of their heating & cooling load calculation program. Once you know how much heat your house looses & figuring 75% efficiency of your existing furnace, you can start to figure how long it would take to pay back the investment into a new furnace. An oversized furnace short cycles & during warm up you are getting no heat into the house. Some is going into warming up the metal but most is going right up the chimney.
If your furnace is typical, it is probably grossly oversized for the house. The best $50 you could spend would be at http://hvaccomputer.com for use of their heating & cooling load calculation program. Once you know how much heat your house looses & figuring 75% efficiency of your existing furnace, you can start to figure how long it would take to pay back the investment into a new furnace. An oversized furnace short cycles & during warm up you are getting no heat into the house. Some is going into warming up the metal but most is going right up the chimney.