Cost of Mod Con Boiler?
#1
08-19-08, 08:15 PM
Cost of Mod Con Boiler?
I am converting to propane. A local supplier sells munckin and weil-mclain (approx 150k BTU/hr input) boilers in the range of $3500-4000. Is this the going rate? I am trying to justify the premium price of these units relative to a conventional boiler. I estimate my payback will take at least 5years - however not sure of the best way to estimate. Any advice would be appreciated
#2
08-19-08, 09:17 PM
Member
Join Date: Jun 2008
Location: Rockville MD
Posts: 101
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Make a spreadsheet with all your heating options listed down the side, and your one-time and repeating yearly fuel and maintenance costs going across for each one. Don't forget things like the cost of removing the old oil tank and getting the chimney lined, if they apply.
You may find that a cheaper boiler will pay back sooner. The biggest trick will be predicting fuel costs and consumption. I assumed a 20% price increase each year.
You may find that a cheaper boiler will pay back sooner. The biggest trick will be predicting fuel costs and consumption. I assumed a 20% price increase each year.
#3
08-19-08, 09:36 PM
Do a heat loss analysis !
HUGE House ? 150K is a darn big boiler ...
I bet you can get one half that size and save a ton of money, both on the boiler and on the fuel that you won't be wasting.
Go to www.slantfin.com and download the FREE heat loss software. It's easy to use, but does tend to overestimate the heat loss a bit (maybe 20% or so...) Only then should you think about what size boiler you need. NEVER size a new boiler from the old one, fuel was cheap, they didn't care...
If you've got an average size home, I bet you come in well under 100K heat loss.
I bet you can get one half that size and save a ton of money, both on the boiler and on the fuel that you won't be wasting.
Go to www.slantfin.com and download the FREE heat loss software. It's easy to use, but does tend to overestimate the heat loss a bit (maybe 20% or so...) Only then should you think about what size boiler you need. NEVER size a new boiler from the old one, fuel was cheap, they didn't care...
If you've got an average size home, I bet you come in well under 100K heat loss.
#4
08-20-08, 07:50 AM
Trooper you got that right. I talked to a guy the other day he got 3 prices. They ranged from 120k to 180k. He had a heat loss done and the loss was 48k. Well worth the time for the heat loss.
If you don't feel comfortable doing the heat loss yourself there are some sights where they will do it for you for a fee.
If you don't feel comfortable doing the heat loss yourself there are some sights where they will do it for you for a fee.
#5
08-20-08, 03:19 PM
The boiler in this joint is 140K. Slant-fin tells me 72K, but actual heat loss based on measured oil use, and degree days tells me it's more like 55K ... so the boiler installed here in 1984 is almost 3X too large.
I bet that 11 out of 10 boilers installed more than say 5 years ago are 2X too large.
I think there's some good reading over at www.comfort-calc.com about this...
I bet that 11 out of 10 boilers installed more than say 5 years ago are 2X too large.
I think there's some good reading over at www.comfort-calc.com about this...
#6
08-20-08, 03:24 PM
I think you are close except for one thing. Instead of the last 5 years it is 11 out of 10 installed today. In all honesty I feel about 80-85% of all boilers installed today are 100% - 150% oversized.
It is an everyday conversation
It is an everyday conversation
#7
08-20-08, 05:42 PM
Member
Join Date: Jan 2008
Location: Rhode Island
Posts: 102
Upvotes: 0
Received 0 Upvotes
on
0 Posts
Why is this boiler oversizing so prevalent? Is it the cya factor to keep customer warm and happy or the sheer lazyness of the installer to do a proper heat loss calc? Maybe the installers just don't know better.
Is it common these days for installers to be trained properly or not?
Is it common these days for installers to be trained properly or not?
#8
08-20-08, 07:51 PM
Join Date: Mar 2006
Location: Wet side of Washington state.
Posts: 16,321
Received 38 Upvotes
on
30 Posts
Mostly cya. A boiler that is too small will be immediately apparent whereas a boiler that is too big will simply be inefficient. Very seldom will someone notice that the boiler fires for two minutes and is then off for one minute as long as the house is warm.
#9
08-20-08, 08:34 PM
Load Calc
I used the slant-fin program on the first floor before the program crashed. It showed that I needed 75K Btu/hr jsut for the first floor. I extrapolated, to arrive at 125k BTU/hr. Then figured I would need I larger boiler capacity based on efficiency. Another rule that I have used is multiply 30 times the home square footage to estiamte capacity. In this case my home his 3600 ft2 and the capacity is 110 BTU/hr.
#11
08-21-08, 09:12 AM
If done properly the heat loss for the second floor will be higher than the first floor as the ceiling for the first floor does not have a heat loss but the second floor ceiling will.
My last house was built in 1919, three story, no side wall insulation, 10" in ceiling and 3" in kneewall on third floor, 1850 sq ft. The heat loss was 68K. If I would do simple math 1850 + 1850 = 3700 sq ft. 68k + 68k = 136k heat loss. So if you home is old and no insulation values you could be close, otherwise not.
My last house was built in 1919, three story, no side wall insulation, 10" in ceiling and 3" in kneewall on third floor, 1850 sq ft. The heat loss was 68K. If I would do simple math 1850 + 1850 = 3700 sq ft. 68k + 68k = 136k heat loss. So if you home is old and no insulation values you could be close, otherwise not.
