Lowest temp to use heat pumps.

[AISTQM]

New 4326 Ventana, what temp do you quit using heat pumps,and use the Oasis diesel heat?

[NWLanding]

We switch to the furnace at 40 degrees. I believe it’s documented and it’s been discussed several times here too.

[docj]

There's no specific temperature at which a heat pump stops working. As the temperature falls below ~40F it will generate less and less heat. At some point you're going to switch in order to keep the temp inside your RV where you want it.

[FLJOE]

I'm certainly not an expert with this Oasis system. What we have found so far is that even with morning temps in the 40's running the furnace instead of the heat pumps takes the chill off quicker. Actually having the diesel burner on instead of just the electric I/II makes the furnace heat the interior quicker IMHO.

[TJ]

Heat pumps will operate below 40 degrees, but they rapidly lose efficiency below that point and go into frequent defrost cycles due to coil freeze-up. The 40 degree point is a good rule of thumb though you won't do any damage running them below that point. I have, on occasion, run mine down to about 37 degrees without a problem.

TJ

[AISTQM]

Thanks

[MikeGriffin]

The Dometic manual says:

"Auxiliary heat operation will be activated when the measured temperature of the out-
door temperature sensor is less than 30' F. If the system is equipped with a furnace,
the control will select FURN heating mode for the auxiliary heat source. Auxiliary
heat operation, once initiated, will have priority over a heat pump defrost cycle.
Auxiliary heat operation will be de-activated and the heat pump operation will re-
sume when the temperature of the outdoor temperature sensor is higher than 35' F. "

[Route 66]

My experience was there was no fixed temperature to switch to central heat, but at some point the heat pump fans were unable to push the heat down to the floor and seating level.

Sometimes, I would switch to propane heat and sometimes use a small electric heater on the floor blowing down the aisle.

[ewlee]

On our LADP with Silverleaf, when the outside temp sensor senses below 40 degrees, the system will automatically switch from heat pump to Oasis.

[luckyd]

Hot air rises, cold air drops.
Hot air from heat pumps does not drop
down to the floor and is also quite noisy.

We use the Aquahot for our heat. It comes
out of floor registers and the fans are fairly quiet.

[docj]

Originally Posted by luckyd

Hot air rises, cold air drops.
Hot air from heat pumps does not drop
down to the floor and is also quite noisy.

We use the Aquahot for our heat. It comes
out of floor registers and the fans are fairly quiet.

The primary reason for using a heat pump (compared to other sources of heat) is usually because heat pumps are significantly more energy efficient than the alternative of using the same amount of electricity for resistance heating.

If was at a park or other location where your electricity is free, then I would always opt for the warmer, quieter solution provided by my hydronic heating system. But if I was paying for electricity, a heat pump would be the preferred solution for temps >40F.

As outdoor temperature falls below 40F, the efficiency of heat pumps is reduced and the device spends a greater portion of its duty cycle reversing itself to defrost. All in all, at some point in the 30-40F range (depending on the specific model of pump and the relative humidity), use of a heat pump becomes ineffectual.

[luckyd]

Originally Posted by docj

If was at a park or other location where your electricity is free, then I would always opt for the warmer, quieter solution provided by my hydronic heating system. But if I was paying for electricity, a heat pump would be the preferred solution for temps >40F.

I am sure you mean this in reverse.
If you are "paying" for electricity, why
use the heat pump?
AH runs on diesel.

[docj]

Originally Posted by luckyd

I am sure you mean this in reverse.
If you are "paying" for electricity, why
use the heat pump?
AH runs on diesel.

I have a 4kW electric heater (a Comfort Hot) for my hydronic system (a Hurricane) that I usually use instead of the diesel-fired system. It allows me to keep the diesel tank full during the winter and reduces the number of hours on the burner and other parts. I only use the diesel-fired option when temps go <20 degrees.

I was using my thought process rather than what others might do. Thanks for pointing that out.

[MonacoMan84]

Originally Posted by luckyd

I am sure you mean this in reverse.
If you are "paying" for electricity, why
use the heat pump?
AH runs on diesel.

I believe some AH systems also have an electric element.....