How many BTU???

Lakewood

My plumber told me that my 1000 square foot house doesnt need more than 30000 BTU. My last boiler was a lot more. He told me he did a heat loss calc and it came to 20000 BTU. I spoke to other plumbers and they all say I need 100000 BTU. By the way I am only heating the house with this boiler, nothing else.

Lakewood

How many BTU???

My plumber told me that my 1000 square foot house doesnt need more than 30000 BTU. My last boiler was a lot more. He told me he did a heat loss calc and it came to 20000 BTU. I spoke to other plumbers and they all say I need 100000 BTU. By the way I am only heating the house with this boiler, nothing else.Who is right?

JohnNY

Rules of thumb....

...can get you in trouble but in the NYC Metro area, 30 BTUs per square foot usually gets you pretty close to where you want to be.
Sometimes it's closer to 25 other times it's closer to 40, but it's never 100.

I'd be inclined to go with the guy who's thinking about it and actually did a heat loss to back himself up.


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DJ_5

The guy who did the heatloss calc is always right unless he did it wrong. If the math is correct, there is your answer. Heatloss trumps all! Since we use car analogys alot around here, you would be sceptical of a mechanic who gave you a quote without having seen your car right? Same thing.

Concerned Apartment Owner

For JohnyNY

Thanks for that information. Curious to know if that applies to high rise apartment buildings too.

Mitch_4

lets do some math here

assuming your house at 1000 sq ft has a perimter of 25 x 40 and you covered EVERY foot with baseboard your max radiation is 78,000 (you do have doors and interior walls right?!?)

a 100000 btu boiler at 80% still gives more than required, and provides 80 btu's per sq.ft.

Lets put it in perspective. I have a 35 year old, 4 lvl side split all original construction, NO structural improvements, weather will be the same as Detroit Mich, and because my old furnace went kaputski, I replaced it with a 2 stage gas unit, 36,000 on low fire, 60k on high..I have disabled the high fire, and have been running on low fire all winter.

My house is about 2200 sq.ft or 2.2 TIMES bigger then yours with a loss of about 16 btu/sq.ft.

remember I have forced air (right now) and I keep my house at 72.

Go with the heat loss..and even better..measure just how much baseboard you have..the number of feet x 600 is your max radiation. Anything above that is wasted boiler capacity..I am constantly ripping out 100,000 - 150,000 furnaces and replacing them with 40's and 60's

Eric L._2

2 stage gas unit, 36,000 on low fire, 60k on high

You wrote:
"I replaced it with a 2 stage gas unit, 36,000 on low fire, 60k on high"

What unit is this? I thought they didn't make them that small!

Mitch_4

It is an

Olsen.

http://www.olsenhvac.com/product_detail.asp?key=156

I love these units..been installing Olsen for 15 years now..they had some issues in the past, but the new stuff is superb. True 4 position units..just soild weel built machines. Different philosophy than most but when you get into them..they are the best i have worked on in quite some time.

Needed to replace a pinging heat exchanger, factory authorized it ..took me 1 hour from start to driving away..That is serviceability!!

Phil_17

HEAT LOSS FOR HO

Do the calculation yourself and you will be happiest. Use both the slantfin program and the info you can find on this site to do it manually. That way you can measure all the walls, the windows and doors and probably will see some places you can help get the envelope greener.