How much propane - Contractor Talk - Professional Construction and Remodeling Forum

banctecbobn · 01-29-2009, 09:39 PM

Is there any programs or charts that would be able to give one an idea how much propane a given furnace would use in a given time period?

I've just used nearly 400 gallons to heat my new 2400 sq. ft. house for the last month. Do the math with the price of propane and you can see my need for this information.

flashheatingand · 01-29-2009, 11:13 PM

One gallon of propane is about 95,000 btu's.

Take a 75,000 btu furnace for an example. If it was running steadily for one hour, you would consume 75,000/95,000=.78 gallons an hour.
100,000 btu furnace. Running steadily for one hour, 100,000/95,000=1.05 gallons/hr.

Hope that helps

neolitic · 01-29-2009, 11:53 PM

If you're in N.Dakota, or
Minnesota, that doesn't
seem too bizarre.
If you're in Fla.......

WarnerConstInc. · 01-30-2009, 11:09 AM

Put your location in your profile!
(Sorry....it seems there really are dumb questions)

Maybe you should make this eaiser to read?

neolitic · 01-30-2009, 11:37 AM

Quote:

Originally Posted by WarnerConstInc.

Put your location in your profile!
(Sorry....it seems there really are dumb questions)

Maybe you should make this eaiser to read?

MechAcc · 01-31-2009, 07:44 PM

Was a heat loss/gain calculation done to size the furnace?

Over sizing a furnace will result in short run times and consume more fuel as the circulating blower is off during the furnace warm up period.

Has a static pressure test of the furnace been done and the blower speed checked against the furnace blower chart to see if the furnace moving the correct airflow?

Will reveal if the furnace blower, secondary heat exchanger or evaporator is dirty or the duct work is inadequate.

Then was a temperature rise test done?

Will tell if temperature rise is too low or if too high causing temperature limits to open cycling burners on and off.

Was the burner gas pressure checked and adjusted per the installation instructions?

If gas pressure was set too low it will take longer to heat the house and consume more fuel.

Was a combustion test done to see if the furnace is firing at the required Carbon Dioxide or Oxygen percentage and the stack temperature is low or high?

A good technician using the static pressure, temperature rise, gas pressure measurement and combustion test can determine if there is a problem with the furnace.

Was a blower door test done on the house to ensure minimal air changes per hour?

Even if the furnace was sized correctly if there is too much air change per hour the furnace may not heat the house properly.

Have you verified that the construction company indeed did install the required amount of insulation?

Even if the furnace was sized correctly for the specs given the HVAC company if inadequate insulation was installed the furnace may not heat properly.