Roof Heat Pump vs Propane.

Paul03 · 10-08-2012, 07:30 PM

Spending two months in Texas this winter at the same campground. They charge for electric and each site has a meter. As we'll need heat at night is the Heat Pump cheaper to operate than the Propane furnace? Same with the hot water heater; electric vs propane.

Mr_D · 10-08-2012, 07:38 PM

Need cost of propane and electricity, then need the efficiency rating of your appliances, then how will you operate them (turn them off when not used, etc). Do they charge extra for propane delivery or will you break camp to fill tank/s?

After that someone might be able to give you a reasonable answer.

Wannabe · 10-08-2012, 09:39 PM

I'm pretty sure that the HW heater is cheaper on propane because you only need to turn it on prior to needing hot water; whereas you will probably leave the electric on. I would suspect that a 110V (as opposed to 220V) heatpump would be hard pressed to beat out a propane furnace, but the availability to fill it would be a deciding factor. This is just my humble opinion which is only as good as the information you gave.

PS: on some of those cold Texas nights the heat pump won't work (below 42) so it's a moot point during those times

harris155 · 10-08-2012, 09:53 PM

Read somewhere there is a 4 to 1 ratio
Propane at 3 dollars a gallon would equal 12 cents a KW.
Camped next to a friend they went all electric we went with propane, not much in it at that rate.

Paul03 · 10-09-2012, 07:47 AM

It's a roof mount, 220v a/c heat heatpump. I have no idea on efficiency factor. Ditto the propane furnace. They came with the 2010 Vista we purchased. The heatpump runs until the air temp is just below 35f.

I suppose I'll just have to get the maunuals out and find the BTU output per hour of each unit, find the BTU per Kwh and Therm per gallon to figure it out. Then compare cost per Kwh and per gallon.

I just thought there was a rough comparison I could go by. But, thanks for the replies.

Wizard · 10-09-2012, 08:31 AM

Are you sure about that 220V, most are 110V

We find the electric so much more convenient than having to track down propane that it trumps the gas.

Jerry

Clay L · 10-09-2012, 09:41 AM

In another thread it was stated that the efficiency factor of heat pumps is so good that they are almost always cheaper than propane. I did some research and it appears to be true.

As far as other appliances go, as said above it depends on the cost of electricity and propane.

If you go HERE you can download a small program that will make the simple calculation for you.
It allows you to enter the appliance efficiency.

According to an email to me from engineering at Suburban Manufacturing, the efficiency of RV furnaces ranges from 70 to 80 percent. Water heaters are 70 percent on gas.

Paul03 · 10-09-2012, 10:44 AM

Actually was an assumtion on my part but upon further review it's probably 120v. Clay, that's the answer I was looking for. So best to just use the propane for the back-up furnace. We only turn on the hot water for showers and dishwashing. But it retains the heat so well that we don't have to turn it on for long.

Thanks all for the replies!

Luckiest Dreamer · 10-09-2012, 11:01 AM

Last winter while in Texas we used electric as much as we could. It seems the park had a bad electric meter that read in our favor making it a better choice for us. The LP was easily purchased daily as a truck made daily rounds thru the park and responded to those that needed LP when they posted a sign in the windshield that the driver could see as he drove down the street. While in Florida the year before the method was to sign on a sheet in the Park office and they driver would stop the next trip thru the park. You paid the driver as the LP was provided. Some parks may not be large enuf to get daily service and you may need to serch out service on your own.

bachler · 10-12-2012, 08:07 AM

"To the post" years ago We were making Parts for a merine/ship/boat heating system. after a lot of studys this is what we found. #1 oil is the hottest/heats the best quickest And cheapest/less expensive;; Propane was the next As it burns at only 2/3 the tempature of oil. and it was a bit more cost per BTU... Next was Electricity It cost a whole lot more and was much more efficent , No exhust ports All the heat is used; And the cost is the same weather you use 110 or 220 . some think you use less when using a 220 input. ???? The final cost looked like this. OIL ; $ 0.30 Propane $0.50 Electricity, $1.00 (This Datta was Collected several years ago)

Doug Sage · 10-12-2012, 08:23 AM

Of course the cost of both propane and electricity varies with where you are parked but I have found that the two sources are roughly the same. There is not enough difference to worry about. My thought is that the decision revolves around availability. Electricity is always there and propane may not be. I would not use propane unless absolutely needed if I had to move the rig to go get more propane. If it is delivered to you at a reasonable price then it doesn't matter which heat source you use.

Triker56 · 10-12-2012, 08:32 AM

If one gallon of propane is equal to 27 kWh of electricity, then we can compare the costs of these fuels directly by looking at the price per unit (propane gallons or kilowatt hours) and finding the price difference. This can easily be done by looking at your electric bill and multiplying the price per kWh by 27. The resulting number will be a dollar figure that will be either greater than or less than the price of a gallon of propane. For example, if you are paying 12¢ per kWh, the electrical cost comparison figure to a gallon of propane will be $3.24 (.12 x 27 = 3.24). Electricity is cheaper than propane if propane is selling for $3.24 per gallon and propane is cheaper than electricity if it is selling for less than $3.24 per gallon.

Electric Air-Source Heat Pump:

(1,000,000 / 3,413 / 2.5 efficiency) x $.10 = $11.72 per million BTU
Propane Equivalent:
(1,000,000 / 91,500 / .9 efficiency) x Y = 12.14Y
$12.14Y = $11.72
Y = $0.97
So, Propane would have to cost less than 97 cents per gallon for it to be more economical than an air-source heat pump.

rvten · 10-14-2012, 01:00 PM

HP is 110 Volt.
We use electric for HP/HWH most of the time.
If you use your propane. and need to get tank filled. Do they have a service that will do it at your site? If not than you have to disconnect everything anddd go get tank filled.
Where we go in TX. proapne delvered on your site.

Triker56 · 10-14-2012, 01:20 PM

I use electric for 2 space heaters & water heater in my FL.(6-7 months) winter spot.
Gas only for cooking and refrigerator when on the road and electric outages.
Sometimes for water heater boost when I want a longer shower.

For the last 14 years I have only needed to fill up the LP tank once a year.
Always do that every September at same place Hicks Gas when on the road in IN.

From 2006 to 2011 those 6 years I have used 46.6 gal or average of 7.76 gal a year for full time use.

SarahW · 10-14-2012, 02:10 PM

What part of Texas? Since we only have 3 days of winter in Houston, you could be running your A/C until December.

dlovitt · 10-16-2012, 08:49 PM

Quote:

Originally Posted by Paul03

Spending two months in Texas this winter at the same campground. They charge for electric and each site has a meter. As we'll need heat at night is the Heat Pump cheaper to operate than the Propane furnace? Same with the hot water heater; electric vs propane.

IMHO

just enjoy your stay in TX and don't fret over a few bucks.