HEIL Furnace question
I am thinking about getting a new furnace this year but want to try to estimate my energy savings. Can somebody confirm the age and efficiency of my current furnace?
HEIL model # GL-175LG-7CR
Serial # of H64862309
Input Rating: 175,000 BTU/HR
Bonnet Cap: 140,000 BTU/HR
One contractor told me it is from '76 while a couple of others said '86. Regarding efficiency, most have told me it is around 60%. How does bonnet capacity relate to the AFUE rating?
Bonnet and AFUE don't really relate to each other. Not on old furnaces anyway.
Yours would probably be around a 60 AFUE.
Don't have old Heil S/N chart but it ain't 86! 76 or earlier at least and definitely 60%ish in efficiency.
175,000 is kinda a lot. we heating a big drafty barn? If not it might be grossly oversized and even less efficient (off cycle loss up the chimney)
Thank you guys, '76 makes sense given that the house was built in '77. The house is a 3400 sq foot quad level with 5 patio doors. All 4 contractors that quoted were in the 110,000 - 120,000 BTU range for 95% efficient models.
Originally Posted by kmarrocco
Heat load calc or guess?? How did they come up with that number?
AND BIGGER IS NOT BETTER
Originally Posted by seatonheating
I just changed out a 130K Rheem with a 60K 95 VS 2 stg. Heating bills are gunna go waaaaaaay down!
" Kill a Commie for Mommy! "
- Colonel David Hackworth (1930-2005), Korean War Vet
Nobody did a heat load calc. All 4 either went based on sf or on the current furnace installed. One contractor offered to do a load calculation at a cost.
Originally Posted by seatonheating
realy should have load calculated. oversize is not better!!!!
how much of the time does the old fire breathing dragon run in the coldest weather?
There are free load calcs online. Just put in address and It will tell you heat and ac btus needed.
We just moved in this May, so I'm not sure how long it runs in the dead of winter.
Originally Posted by fearlessfurnace
So now I'm thoroughly confused.... I had another contractor out to do a load calculation (reputable company). Based on what I read here I was expecting him to come in below the 110,000-120,000 btu quotes I had from contractors who did not calculate the load. I was hoping to get some confidence that a 90k (Lennox) or a 100k (Carrier) would be plenty for my home, then I could go ahead and sign a contract. At the very least, I thought they would confirm the quotes I already had were in the proper size.
His calculation came up with 156,000 btu's (output) needed. This cannot be right. My current 60% efficient 175k btu furnace (105k btu out) has been in the house for 34 years and the previous owners have lived with it, so it must be doing a decent job. On top of that, it still works so it cannot be over stressed.
At any rate, he suggested the 135k Lennox G61V, but it is just short of 95% efficiency and is not eligible for the federal tax credits. That is a deal breaker, so he then offered a 120k btu York model even though it is much less than his calculation result.
After watching and helping him take measurements, I downloaded a load calc spreadsheet and ran my own numbers later on. I am getting around 75k total btu's needed.
For what its worth, the online calcs based on location and sq. footage estimate I need 115,000-126,000 BTU's out (depending on which calc I use).
Summary of the contractors I've had out so far:
Contractor 1: Will do a load calc for added cost, but insists the 110k, 95% efficient unit quoted is as small as I can go.
Contractor 2: Will do a load calc after I commit to purchasing a unit (120k size, 95% efficient quoted)
Contractor 3: Will not do a load calc. Quoted 120k, 95% efficient unit.
Contractor 4: Will not do a load calc. Quoted 120k, 95% efficient unit.
Contractor 5: Will not do a load calc. Stated he would have to open some walls to see what type of insulation is inside. I did not ask him to quote.
Contractor 6: Left a message specifically requesting a load calc. They did not return my call. I am guessing that they did not want to do the load calc.
Contractor 7: Was willing to do a load calc. Calculated 156k output needed.
At this point, I'm at my wit's end and am thinking I am just going to go with the sizes recommended in the quotes I have. I am running out of additional contractors to call and it is taking much more time than expected. It seems that most contractors only use load calcs on new construction and are afraid to do one on an existing house. Perhaps this is because of the assumptions that need to be made (insulation R value, etc). Has anybody had similar experience when trying to request a load calc on an existing home?