hot floors

[upsidedown_Char]

Our new MH has two AC units. Both work with ceiling ducts and I see ducts on the floor which I suspect are returns. The first cold night, I smelled something like hot plastic. I ignored it believing that the new system will do that for a while.

When I went to bed, I noticed the floors were warm which made me wonder if the vents in the floor were indeed returns. The only way I can figure how the floors get warm is from the ceiling vents which blow sweet warm air. Does this sound like normal operation? Everything was fine the next day so I'm just curious.

[SCVJeff]

So now you know how it comes on, is there enough air coming out of the floor or if it just burning off paint and dust?

[upsidedown_Char]

The roof top units are heat pumps. They're good down to ? outside temp. Heat pump or gas furnace is chosen by switch. The heat pumps auto reverse at + - 2 degrees from set point. We changed the thermostat by more than 5 degrees and caused the furnace to come on. The systems are much smarter than me and our 1978 boat.

[naturist]

Given that hot air rises and cold air sinks, it makes no sense to use floor level returns for an AC. AC returns should be up near the ceiling, where the warmest air is, not on the floor, where the cold air that just came out of the AC is.

Floor vents would be for the heating system.

AC's thus put both outlets and intakes up high, while heating systems put both low.

[upsidedown_Char]

I'll get to that in the smart papers. Don't think I want to know badly enough to go back. But, I'll find out tomorrow. Lots of reading time. I ran into another Sightseer last weekend. The owner was happy to explain systems I asked about.

I did read in the PDF that raising the thermostat by 5 degrees in heat mode would make the propane furnace come on. The Captain likes instant heat gratification so she may have goosed it and the heat in the floor was from the gas furnace. That may be the answer.


EDIT:
More digging. Heat pump works to 36 degrees. Then as someone says the furnace kicks on when the difference is more than 4 degrees. The floor was warm because the furnace came on in addition to the heat pumps. I did not know it would turn on gas heat automatically from electric heat mode because there is a gas mode as well. It must have been colder than I thought.
I guess all of this automatic stuff is good.

Boat heat pumps use water temps and below 40 degrees they stop making heat. Never been in water that was under 45.

[Allworth]

Your dealer should have explained all heating and cooling options during your Pre-Delivery walk through.

If they did not, take it back and have them do it in detail.

[upsidedown_Char]

I haven't turned on LP heat. All of this is happening from the ceiling heat pumps. If the floors are heated, it's electric and waaaaay cool.

[K_Charles]

when we turn the AC on heat it comes out the ceiling vents but if it is 3 or 4 degrees colder then the thermostat it also puts on the LP furnace to help the heat pump. Then the heat comes out the floor and the ceiling.

[SCVJeff]

Yours is newer than mine. But we have both an LP floor heater (with return in the rear), and a heat pump on the overhead that either heats or cools.

Look at your thermostat because it controls both, and you can have both on at the same time. BUT if you REALLY feel no air when the LP heater is on you need to find out why

[BB_TX]

Roof mount A/C units exhaust their heat directly to the outside, not thru any internal duct work. And the return ducts simply carry the room temp air back to the A/C units. Something else is apparently going on. Is it possible you actually have heated floors? Even some mid to upper level 5ers have heated floors now.

[upsidedown_Char]

There is hot air coming out of the multiple ceiling vents. I just can't feel air from the floor vents. I think it is coatings and dust burning off. We have not tested the heat on LP. But I can tell you people pay a lot of money to put floor hearers under tile floors. The warm floors are a seriously great perk.

[DrewE]

korbe wrote:
My floor vents are for the heating system. My AC return is at the unit.

x2 on this. Floor vents would usually be furnace vents and blow your sweet warm air. What you're smelling is probably dust or oil residue or similar on the furnace heat exchanger burning off. It can take a bit for it to all clear up, particularly if the furnace is brand new.

My motorhome is set up with wall vents next to the floor for the furnace, but it's otherwise the same as korbe's.

[korbe]

My floor vents are for the heating system. My AC return is at the unit.