Thoughts on circulating warm air in the RV?

When I am on shore power we run an electric heater to warm up the trailer, when it is warm I turn on the fan only on the a/c system an it circulates the hot air in the ceiling through the trailer. With the electric heater running and the a/c fan (on low) running it keeps the trailer at 71 degrees. Outside temp is in the mid thirties. Have to keep an eye on the windows for condensation and dry them once in awhile also.

Bill

I do not have a ceiling fan.

When It is very cold and I want to equalize temperatures in my trailer I run the air conditioner on low fan without the compressor.

If there is too much air flow in a certain area I just close or adjust the vent in that area.

3oaks wrote:
Warm air rises by natural convection. I would think you would want the fan pushing the warm air down rather than pulling it up. The reason you feel a chill is that the air flow across your body tends to evaporate moisture from your skin, making you feel cooler.

For winter time you want the fan pulling the air up.

2gypsies wrote:
Have you thought of using a propane heater? They create a constant warmth and are very economical. We used one for 16 winters.

Yes, the Big Buddy or the catalytic heaters work well for heating small spaces. Since they are burning inside an RV, open windows or vents are necessary for fume removal and oxygen replenishment.

I have a vented propane heater in my 22' trailer. This replaced the typical RV furnace. The Sportsman heater I have is 20K BTU and when the trailer is up to temp, we turn it down to idle or just the pilot. Depending on outside temps and door openings, it sips propane. It doesn't have the typical furnace fan so doesn't draw down batteries. I have used a small computer fan near it to move heat further into the cabin.

I have 2" pipe to the heater for combustion air and for stack air. There's little sense to be exhausting or burning the cabin air since the make-up air will come from outside through any openings, principally through the door seals.

Have you thought of using a propane heater? They create a constant warmth and are very economical. We used one for 16 winters.

Blowing air across surfaces that are in the conductive heat transfer part of heating an enclosed space will tend to increase the transfer rate. You can prove this by sitting in the center of a room where active heating is taking place. Now move to an exterior wall and either place hand on wall or stay in that area. You should notice temperature differences.

There are a few things working against you in an RV: the limited amount of wall and ceiling cavity space able to be insulated, the typical RV construction of not having a thermal break between interior paneling, wall framing, and exterior surface, the lack of insulated glass, and the inefficiency of typical RV furnaces and ducting. Anything you can do to raise efficiency of these is a definite winner. Some of these are nearly impossible or unlikely to be improved but there are a few practical things that can be done. Covering expanses of glass with an insulating material can prove very effective. Extruded foam board inserts placed in window openings at night is a good choice. Making sure that all ducting from the furnace is operational and not laying against a cold exterior surface is a good thing. Placing a fan behind any heating appliance to increase warm air flow and heat transfer from the appliance works well.

Possibly the best improvement in heating an RV through Winter is skirting the RV so that trapped air underneath is higher than ambient. You could even add heat lamps underneath to increase that trapped air temperature. Be careful of growing weeds and flora underneath as Winter progresses. I've camped in sub-zero f environments and skirting increases the comfort drastically.

Reverse circulation with ceiling fan does move warm air at ceiling down BUT even on low speed that ceiling fan may move more air then is actually warm.

Try using A/C Fan on low speed.
It will suck warm ceiling air into return and then blow it out thru the ceiling ducts

Every fan maker will tell you to do as the op does. Blow down in summer which simply creates a breeze across your skin but does blow warm air down. In the winter you still want to move the air but do not want the breeze. The chill may well be from the air being blown across cold windows.

Winter time fans PULL the air up so as to not create a breeze while circulating the air. Summer time you want the fans blowing the air down to create a breeze.

From years of experience at the cottage during cool weather we keep the fan on low pulling air up and forcing it down along the walls.
A faster speed creates a breeze, not necessarily a warm one. All you need is a constant flow.