Elec heat

[46490]

Are electric heaters considered the same as heat pumps for the 2014 Meridian 34 B, or are heat pumps considered something else. This is all new to me and I just want to get the terminology correct. How low will the electric heaters go to keep the MH warm when on shore power? Thanks in advance for your advice.

[Ranger Smith]

On ours the electric heat is the heat pump. Ours works real good down to 40 degrees then the furnace will automatically come on.

[Pelledan]

Heat pumps are air conditioners basically running in reverse. They absorb heat from the outside and reject it to the inside. They can only operate that way with an outdoor temp above about 35-40 degrees. Below that they are very inefficient and your system will automatically switch them off and bring the standard furnace on line. When they operate in their heating mode, the same compressor for air conditioning is used for the reverse operation and as such you will be subjecting it to the same wear and tear as if it was cooling your coach in summer. Instead of using the heat pumps as a heating source, consider one or two 1500 watt electric heaters to heat your RV. They will be more efficient and probably less noisy and won't add wear to your air conditioners. However, if outdoor temps will go below freezing, your ducted furnace will need to operate to keep the holding tanks and wet bay from freezing, so in that case use the electric heaters in a lower wattage as a supplement only.

Dan

[wa8yxm]

Alas ELectric heat can me Heat Pumps. on many T-Stats if it says "Electric" that's what it means.

It can also mean resistive heaters.

[jharrell]

Originally Posted by Pelledan

Instead of using the heat pumps as a heating source, consider one or two 1500 watt electric heaters to heat your RV. They will be more efficient and probably less noisy and won't add wear to your air conditioners.

Heat pumps are usually 3-4 times as efficient as standard electric heaters. Standard resistive heaters have a COP of 1, that is for every 1 watt of electricity they emit 1 watt of heat, heatpumps however move heat from outside to in, therefore for every watt of electricity they move 3-4 watts inside, in other words they are over unity or greater than 100% efficiency.

https://en.wikipedia.org/wiki/Coeffi...of_performance

A normal heat pump using 1500 watts will act like a heater putting out around 5000 watts so long as outside temperatures are high enough to prevent it's coils from freezing.

[alank]

Let me throw my 2 cents worth in on this, Pelledan pretty much covered what you asked and jharrell corrected his error on efficiency of the heaters.

We have two 1500 watt heaters in our 36Y and they do fine down to 32* and operate quitter than the heat pump. We use then day or night. Much below freezing use the furnace for reasons indicated above. Each heater will need to be plugged into a separate circuit with not much else on the circuit to prevent tripping the breaker. We have to switch ours around to avoid the coffee maker or hair dryer or other such things while they are being used

Our heaters are floor models that oscillate, about 30" tall and have thermostats that turn them off. I wanted to buy small 1500 watt heaters mostly because they took up much less space, but as my wife pointed out, those little 1500 watt heaters won't put out enough heat like the big ones will so we got two floor model 1500 watt heaters.

To me 1500 watts is 1500 watts, but some battles just aren't worth winning.

[Pelledan]

I must say that I stand corrected regarding the efficiency of heat pumps. When we bought our unit 5 years ago the previous owner demonstrated all the operational components of the RV including the heat pumps. The genny was running, so I could see the amp draw at the panel as each compressor (basement unit) came on line, so I knew it was working. However, during the following conversations the PO stated that he preferred to use space heaters as he felt they were more efficient. I thought nothing of that and immediately purchased 2 space heaters and have never used the heat pumps after they were demonstrated. I have since read up on their efficiency after my first post and agree they evidently are far more efficient that space heaters, but the component wear issue is concern enough for me to continue to use space heaters.
Dan

[jharrell]

Efficiency is one aspect, what interesting about heat pumps is is they are basically solar assisted heaters, they pull heat from the outside air and pump it into your RV, the outside air is warmed by the sun.

Most people get tripped up by heat pumps because the confuse temperature with heat. Heat pumps work by changing temperature in the refrigerant gas using a compressor causing heat to either be absorbed or rejected to the outside. There is always heat in the air no matter how cold it is so long as we are above absolute zero (−459.67 degrees F!), however air source heat pumps can't pull it out below about 40 degrees because the outside coils get below freezing and ice up blocking air from moving over them to get heat from.

The other aspect is they actually put out enough BTU's to easily heat the coach, a 1500w strip heater put's out about 5000 btu's, a 1500w heat pump will be at 15,000 btu's! One heat pump is 3 space heaters and you still have amps left over to do other things on 30a service.

As far as wear and tear no different than running A/C, it's just running the A/C in reverse, it what they are there for to run. You won't be using them below 40 degrees anyway might as well get use out of them before switching over to propane heat.

Wish my coach had a heat pump, only came with A/C and propane heat, may get some space heaters to use when on hookups so I don't use propane as much. If anything ever happens to my A/C it will be replaced with a heatpump.