Heat Pump vs. Propane Furnace

[Jsmagill]

I apologize in advance for reposting the question, but I couldn't find a clear answer in other posts. We have a 2008 Diplomat with two heat pumps in our overhead air units, and dual propane furnaces. This is our first winter staying in the coach. Received our first electric bill today (using the heat pumps and occasional electric fireplace @ 1500 watts) and it was about $90.00 for 3 weeks service. Temps are mid 60s during the day, but dropping to low 40s and 30s at night. It appears that the heat pumps fail to provide adequate warmth at night when the temps fall, and they are noisy. The propane furnaces heat the coach nicely, but then we have the humidity and dry, hot heat issues. Question: which are more economically efficient to operate, electric heat pumps or dual propane furnaces?

[Steve Ownby]

Originally Posted by Jsmagill

I apologize in advance for reposting the question, but I couldn't find a clear answer in other posts. We have a 2008 Diplomat with two heat pumps in our overhead air units, and dual propane furnaces. This is our first winter staying in the coach. Received our first electric bill today (using the heat pumps and occasional electric fireplace @ 1500 watts) and it was about $90.00 for 3 weeks service. Temps are mid 60s during the day, but dropping to low 40s and 30s at night. It appears that the heat pumps fail to provide adequate warmth at night when the temps fall, and they are noisy. The propane furnaces heat the coach nicely, but then we have the humidity and dry, hot heat issues. Question: which are more economically efficient to operate, electric heat pumps or dual propane furnaces?

The closer to freezing the temp gets, the less the heat pumps perform. Much under 40 outside temps & you should switch to the LP furnace. You can supplement with your fireplace of course.


Steve Ownby
Full time since '07

[wa8yxm]

If you are paying for it in theory the Heat Pump is more efficient but.. only above about 40 degrees outside.. Humidity issues should be the same as with the propane burner (Neither add, or remove, moisture but both drive humidity down due to heating of the air).

HOWEVER: Some states allow the campground to "Mark up" electricity, this .... Might change things (in favor of Propane)

Also Propane heat tends (in motor homes) to be "in the floor" (Registers in the floor spew out the warm air) where as the heat pump tends to be in the ceiling,, Heat rises don't you know.

[nodine]

Originally Posted by Jsmagill

I apologize in advance for reposting the question, but I couldn't find a clear answer in other posts. We have a 2008 Diplomat with two heat pumps in our overhead air units, and dual propane furnaces. This is our first winter staying in the coach. Received our first electric bill today (using the heat pumps and occasional electric fireplace @ 1500 watts) and it was about $90.00 for 3 weeks service. Temps are mid 60s during the day, but dropping to low 40s and 30s at night. It appears that the heat pumps fail to provide adequate warmth at night when the temps fall, and they are noisy. The propane furnaces heat the coach nicely, but then we have the humidity and dry, hot heat issues. Question: which are more economically efficient to operate, electric heat pumps or dual propane furnaces?

If your 2008 Diplomat is anything like our 2006 Diplomat then all you need to do is set the thermosat mode to heat pump for both units and make sure the propane is turned on. When the outside temps get to low for the heat pumps the thermosat will automatically switch over to the propane furnaces and then back to heat pumps when the outside temp goes back up.

Our coach has dual pane windows and I would hope yours is the same. You should have very little condensation on the windows but the windshield is another story. Keeping the curtains closed on the windshield will help.

Bob

[smlranger]

Agree with all here. Heat pumps OK in temps above mid thirties then start to loose their ability to extract heat (except some of the very efficient residential units available). Also remember that heat pumps produce cooler 'warm' air than any fossil fuel heat source. So even if the heat pumps are doing OK, the cooler air (maybe 96F) at high flow will feel cooler to you than 110F air coming from your LP furnace at a lower flow and closer to the floor.

[Jsmagill]

Thanks for your comments! If the nighttime temps are in the low 40s, and the park charges me for electricity, which would be more economical to run, the electric heat pumps or the propane furnaces?

[jacwjames]

A lot of variables, price of propane, price of electric, how old are your AC units, how tight is your RV.

I do not think either the AC Heat Pump or Furnace are that efficient. We run small space heaters if needed.

We camped down at the Orlando Fairgrounds for the Eukanuba Dog show in December and it got down into the low 30's a couple of nights, had a real heavy frost one morning, I watched it form on the car while I was walking the dogs. We did not run any heat at night, had a nice comforter on the bed and that was it. Once we were up my wife would start a small space heater in the back to take a shower and that was it. We were comfortable and the coach seemed to keep the heat.

Some tricks, if you have a fantastic vent get a pillow to prevent heat loss, the same with the Coolmatic fan. We pull the curtains across the front and even have another set of collapsible window covers if its real cold (or hot). We do have dual pane windows which is a must (we had a Class C with regular window and froze under similar circumstance). Make sure all your basement door seals are tight to prevent heat loss in the basement.

Good Luck

[DMTTRANSPORT]

@ around 40 degrees our heat pumps default to the propane furnace, we like the pump better, jmo

[Rburian]

We use two ceramic heaters, and set the furnace at 62, at night, the heat pump does not go on and the furnace only comes on occasionally. We keep the rear furnace off at night.

[bluepill]

With our floor plan (lots of windows and a big slide up front), hanging a spare blanket between the front and back sections as a thermal curtain and using a small electric heater in the bed/bath section works well. Rear stays at around 60 degrees, which we find comfortable, and front is usually down to 45 or so in the AM.


At wake-up time, the small heater goes into the shower to warm up the enclosure walls and I set the LP heat to 72 degrees which brings the whole unit up to a comfortable temp within 15 to 25 minutes depending on outside temp. and sunshine.

[Denali]

Originally Posted by Jsmagill

...Question: which are more economically efficient to operate, electric heat pumps or dual propane furnaces?

The answer:
http://www.eia.gov/tools/faqs/heatcalc.xls

[flynnwalter]

Jsmagill
Make sure you read your meter and take a pic with your phone-that seems pretty high for 3 weeks. Are you familiar with a catalytic propane heater? While I would not run one when sleeping (CO), they are perfectly safe heat. No electricity used. You can set up a quick connect maybe underneath your stove, and of course you could run more than one at a time if its really cold. Here is one example Amazon.com: Camco 57331 Olympian Wave-3 3000 BTU LP Gas Catalytic Heater: Automotive

[smiller]

Beyond the operating limitations of the heat pump (modern multi-stage residential units have a wide operating range but RV units are still pretty limited) the economic equation comes down to the cost of electricity vs. propane. Often this is a near wash, but RV park operators frequently mark-up electric rates enough to tilt the balance in favor of propane.

[Jsmagill]

Thanks, everyone! I appreciate your quick responses. Jerry