Replacing AC with AC+heat pump or heat strips

[RnRushin]

2016 Surveyor 32BHDS - with 50 amp service, 2 A/Cs, arctic package with fire place

I'm going to replace the main ducted a/c, 15K Dometic Duo Therm myself. It was low on 410a this spring and I had it charged. It worked great until this week when the unit was turned off. When it was turned back on a day or so later now it does not cool and froze up. I'm going to replace it instead of recharging.

I'm looking at a Dometic Brisk II as a replacement. I'm considering upgrading to a heat pump unit or adding heat strips.

I have determined I will have to replace the thermostat to one that has heat pump or heat strip setting.

Will I have order a control box or does it come with the a/c?
Will I have to replace my three conductor thermostat wire?

Any suggestion on heat pump model vs adding heat strips?

I would like to get everything ordered so next weekend i can knock this out and plan a trip.

Thanks
Robert R

[cavie]

stay with AC and furnace. KISS

[RnRushin]

Thanks but late season and early season camping wife gets cool and would like something to take the chill out for her without turning on the furnace. I'm replacing the a/c any way. I'm handy enough to do the project just want to make sure I have what i need when I start.

[cavie]

I based my response based on many many threads of unhappy people with heat strip units. Mostly from Atwood owners. Many dissatisfied they the Air Sampling system. Constant on off of the fan. As an electrician, my thought is heat strips are not efficient in an RV. But that's me.


grab some beers and do a search on the link on the top right of this page. Hours of reading.

[Duckogram]

From my own experience: I had 3 BriskAir II failures on my 2014 Coachmen. They fail because of leaks. The problem stems from improper assembly in China. I have a new replacement sitting in my storage building collecting dust. Come get it (when I get home) It’s free. Nuff said about that.

Now I have an Atwood (Dometic) Air Command AC-1511B heat pump. It works ok but the design is faulty in many ways (IMO). The heat pump sensor is in the plenum. It does not use the thermostat to tell it when to run. It cycles every couple of minutes to sample the air but the air it is sampling is not at room temp so it operates well behind the demand temp you set on the thermostat. Then it puts out semi warm air from the ceiling ducts. Not rocket science to know that the warm air never gets to the bottom half. It also draws return air at the ceiling. Can I get a “duh”?. The good news is that you do get some heat (down to 40* OAT) without burning your propane. A nice ceramic heater would be more efficient but only in a smaller space.
Next is the badly designed interior grill. It causes too much back pressure resulting in water penetration from condensation. i.e. it will rain under the unit. Dometic is sending me a substitute but it requires a garnish to cover the holes. I’ll get one of those when they make them. On a positive note, the Atwood is very quiet.
As for cooling, it works well. It kept my 30’er cool (80* or less) in 110* Palm Springs heat a few weeks ago. I do agressively manage heat penetration.

On to replacement. You may or may not have a compatible control box and thermostat. When you make your choice, you can sort that out. You may have to get a new interior grill as well.

My .02¢ worth. I would go with a high performance A/C only unit. Then buy a really nice 1500W ceramic heater for the boss.

Have you looked at the Coleman Mach 8 series?

[cavie]

Originally Posted by Duckogram

From my own experience: I had 3 BriskAir II failures on my 2014 Coachmen. They fail because of leaks. The problem stems from improper assembly in China. I have a new replacement sitting in my storage building collecting dust. Come get it (when I get home) It’s free. Nuff said about that.

Now I have an Atwood (Dometic) Air Command AC-1511B heat pump. It works ok but the design is faulty in many ways (IMO). The heat pump sensor is in the plenum. It does not use the thermostat to tell it when to run. It cycles every couple of minutes to sample the air but the air it is sampling is not at room temp so it operates well behind the demand temp you set on the thermostat. Then it puts out semi warm air from the ceiling ducts. Not rocket science to know that the warm air never gets to the bottom half. It also draws return air at the ceiling. Can I get a “duh”?. The good news is that you do get some heat (down to 40* OAT) without burning your propane. A nice ceramic heater would be more efficient but only in a smaller space.
Next is the badly designed interior grill. It causes too much back pressure resulting in water penetration from condensation. i.e. it will rain under the unit. Dometic is sending me a substitute but it requires a garnish to cover the holes. I’ll get one of those when they make them. On a positive note, the Atwood is very quiet.
As for cooling, it works well. It kept my 30’er cool (80* or less) in 110* Palm Springs heat a few weeks ago. I do agressively manage heat penetration.

On to replacement. You may or may not have a compatible control box and thermostat. When you make your choice, you can sort that out. You may have to get a new interior grill as well.

My .02¢ worth. I would go with a high performance A/C only unit. Then but a really nice 1500W ceramic heater for the boss.

[cmysstailights]

Originally Posted by cavie

Attachment 186734

There is a 12v and 48v mini split units with heat pumps. Just food for thought.

[cmysstailights]

http://www.hotspotenergy.com/solar-air-conditioner/

[rjshiflet]

I realize things can change quickly, but on our Cardinal we have the Dometic heat pump/AC and it has worked great. Once the outdoor temperature drops below about 38 it's pretty ineffective but the furnace is certainly capable of warming things even well below freezing.

Taking the chill off seems to be the heat pump's best task, it certainly doesn't heat once the temperatures drop too low. And, we have our fireplace that generates a good bit of heat.

All-in-all we are happy with the heat pump/fireplace/furnace our unit is equipped with.

[Witch Doctor]

Originally Posted by rjshiflet

I realize things can change quickly, but on our Cardinal we have the Dometic heat pump/AC and it has worked great. Once the outdoor temperature drops below about 38 it's pretty ineffective but the furnace is certainly capable of warming things even well below freezing.

Taking the chill off seems to be the heat pump's best task, it certainly doesn't heat once the temperatures drop too low. And, we have our fireplace that generates a good bit of heat.

All-in-all we are happy with the heat pump/fireplace/furnace our unit is equipped with.

I agree with this, I have the same and it works well above 40 degrees, lower then that use the furnace, your Dometic HP will come with the control panel also they work on 3 wires, only thing your going to need is to get the Dometic stat for it which is also 3 wires. Do not just get a new A.C. a waist of money, also I have not had a problem with it searching. It really works well to take the chill off, plus you can always add a 1500 watt heater being they are not on the same electrical circuit. Don't need to use your propane until it gets below 40 outside. You will be sorry if you don't do it...

[Bluepill]

Supplying heat from above is much less comfortable and efficient than from floor level. As far as comfort, the DW and I both don't like the feeling of being warm on top and cold on the bottom. It just feels weird. The heat pump is also noisier than than a small electric heater.

All that said, no harm in trying it. You can always buy that stand-alone heater.

[RnRushin]

Thanks for all the replies and suggestion. As i thought, the 3 conductor wire to the thermostat will work as it sends a signal to the control box.

This site is great

thanks
Robert R.