Propane Furnace Operation

[randm]

We have a 95% efficient propane furnace and are trying to use at maximum efficiency. Our day time temps are in the 50's and nigh time are in 20's. We normally turn off at night and on in the morning. Would it be more efficient to leave on all the time?

[stickinit2thman]

Do you mean completly off? if so yes it uses less energy generally to keep at constant temp, small savings can be realized be using a set-back t-stat. You set to keep lower temp at night and bring it up in daytime,you want to keep set back within reason im guessing here but prob. 10-30deg. max. this way yu shouldnt experiance excessive run time to recover.hope this helps, you can use search function to look for setback temps or programmable t-stats, pretty sure youll find something.

[randm]

Thanks, The furnace is new and last year we tried shutting it off at night and ended up with a $600.00 propane bill for 30 days so I thought we must be doing something wrong. We will setback to 60 at night and 69 in the daytime. Thanks for your response.

[gregp]

Thanks, The furnace is new and last year we tried shutting it off at night and ended up with a $600.00 propane bill for 30 days so I thought we must be doing something wrong. We will setback to 60 at night and 69 in the daytime. Thanks for your response.

look at the $ amount, be concerned with the actual gallons used.

[randm]

200 gallons

[gregp]

you used 6.67 gallons/day. I would not turn the unit all the way off, and try setting ther t-stat back no more than 5-10 degrees. Is the furnace the only thing that uses propane?

[randm]

Yes only the furnace.

[wahoo]

If you take the 6.67 gal/day use times 94,000 btu/gal, then times 95% eff. and then divide by 24 hours in day you'll reach about 25,000 BTU/hour heat loss of home. This means the house must have lost @25,000 btu per hour in cold weather. The cost of the propane is the problem, as this is a fairly low heat loss amount. The actual amount of propane used is fairly small based on my figures. The problem with propane is the fluctuating price and the fact that you pay all at once when tank filled instead of a monthly bill. If you turn the heat all the way off, then what's the chances you'll freeze some plumbing? I'd use a programable thermostat and set it back at night only, never turn all the way off.

[2old2rock]

It seems you're in a mild climate. I would seriously look at an air source heat pump.
It could pay for itself quickly with what you're paying in propane.

[SkyHeating]

It seems you're in a mild climate. I would seriously look at an air source heat pump.
It could pay for itself quickly with what you're paying in propane.

Air source or geothermal heat pump for sure. I am in the process of quoting a WaterFurnace geothermal system for a homeowner here in Oregon who has propane bills for the whole winter that total $4,500 in an average winter, vs the $1,200 a year at most he will spend on a new geothermal unit for the same thing.

However, this takes property to put in a geothermal unit but there are signifigant advantages(and tax credits) in regards to geothermal vs air source.

[randm]

We just sold our home in Oregon where we had a heat pump and our bills averaged around $200.00 a month summer and winter. The home we are currently in is a mountain cabin in California that we are going to be living in for six months and will be selling it and moving to a home on the coast that has a heat pump. The heat pump on the coastal home is a 13 seer so we may change it out when we move there with a more efficient unit.
Thanks every one for your input.

[udarrell]

We just sold our home in Oregon where we had a heat pump and our bills averaged around $200.00 a month summer and winter. The home we are currently in is a mountain cabin in California that we are going to be living in for six months and will be selling it and moving to a home on the coast that has a heat pump.

The heat pump on the coastal home is a 13 seer so we may change it out when we move there with a more efficient unit.
Thanks every one for your input.

There are a lot of factors to consider when thinking that raising the SEER level will automatically result in a reasonable timeline payback.

Making your home & duct system's airflow more efficient might provide more return bang for the buck for both heating & cooling. Just a thought...