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MissPearl · 10-06-2013, 09:15 AM

I too am going through this thought process. I have an 89 Excella w a Coleman Super Mach. Fan only works on low. Compressor kicks on and off. I'm in New Orleans (very humid) so it frequently freezes up with only mild temps outside.
Any suggestions???

Mixter · 10-06-2013, 09:23 AM

I think rodsterinfl has a good point

"set the fan to high and temp to mid point. The inside temp went to about 78 degrees F and humidity lowered to the low sixties (percent). Obviously the AC was working fantastically to get such a low temp in a hot environment (I thought 20 degree diff was a limit) and it did not freeze up the rest of the weekend - more circulation took care of that. "

Makes me wonder if I need to re-think the 15k BTU size....

SteveSueMac · 10-06-2013, 09:27 AM

Hmmm - my trailer is at the storage site (along with the bag of all the instructions for stuff like that...). How do you set the fan and temp differently for the AC? I think I've always just set the temp at the Dometic control unit on the bedroom wall. I don't recall a setting for fan speed?

idroba · 10-06-2013, 10:20 AM

Just a report on the Dometic heat pump AC unit that is standard factory issue now on the FC series, including my 20'.

I rarely use AC other than when it may be hot at home, and I have power and want to work in the trailer. However as the unit is new, this year I ran it for about 2 weeks to get some hours on it, in case it had any early failure issues which would be covered by warrantee. It seemed to cool well although somewhat noisy. No worse though than any other RV AC unit I have had over the years. I hate the complex thermostat, although I have become used to how to operate it now. But you can set it so the fan cycles with the compressor, so the fan is not roaring inside and out all the time. I like that.

I have just returned from a trip to Glacier Park area. I have friends who own a cabin just outside the park, and I can stay there, and have power. It was wet, cold, rainy and even a little snow. I thought I would try the heat pump part of the AC unit. To my great surprise, it worked pretty well. It dropped to 35 a couple of mornings, and the high temp was in the mid 40's while I was there. The heat pump continued to pump nice warm air even when it was 35 out (no heat strip on these units either, so it had not switched to all electric resistance). I had it set so the fan cycled off and on when it needed heat, and that also worked well. No cold drafts when the compressor was off but the fan running, just warm heat and air when the thermostat called for heat. Occasionally the unit went into defrost mode, where I could hear the compressor running, but the inside fan was shut off, so no cold air was cycled into the trailer.

I also could step out of the shower, push the outlet to blow warm air straight down on my head and dry my hair quickly, as well as the top half of my body. Kinda nice.

After reading all the comments on how poor the heat pump features were on older RV AC units, I was pleasantly surprised to find how well this new 2014 one works. I had never had a heat pump AC unit in the past.

So, the new ones do work into the mid 30's at least, have defrost capability, and produce good amount of heat. Still noisy, but I can live with that.

rodsterinfl · 10-06-2013, 07:50 PM

Quote:

Hmmm - my trailer is at the storage site (along with the bag of all the instructions for stuff like that...). How do you set the fan and temp differently for the AC? I think I've always just set the temp at the Dometic control unit on the bedroom wall. I don't recall a setting for fan speed?

My unit is a ceiling mount with the controls on the unit. There are two fan speeds on one knob and the other is the temperature knob. I DID get a new air distribution box for better management of airflow. The older unit (air box only) allowed only for air front or back, blowing right on you when sleeping. Problem was that the beds were both front and back.

rodsterinfl · 10-06-2013, 08:08 PM

If you have one of the round looking wall control units I believe you can toggle to fan then set your fan speed.

SteveSueMac · 10-06-2013, 08:28 PM

Quote:

Originally Posted by rodsterinfl

If you have one of the round looking wall control units I believe you can toggle to fan then set your fan speed.

Thanks. I really have to get back to the trailer. I don't recall any knobs on the AC unit itself and I'll have to cycle through the thermostat options on the wall. Thanks!

MissPearl · 10-07-2013, 10:38 AM

Any ideas on why the fan would only work on low and med? Also, I see no noticeable fan speed difference between low and med.

BeachHouse · 02-24-2014, 08:51 AM

Does anybody know if the Coleman Mach 8 HP is noisier than the AC only model? Several people have commented that the Penguin II HP is noisier than the AC only model.

I have learned that you can't get the Penguin II 15000 BTU model with a heat strip, just a HP or AC only. The smaller 13500 BTU unit comes with a heat strip. Dometic told me that can anyone confirm?

It seems that the Coleman Mach 8 HP can also have a heat strip. Anybody know how the controls work for this. Does it just switch to electric heat below a certain outside temp? Because it seems to me that at a cold outside temp, the heat strip wouldn't be sufficient anyway and you would have to change to the furnace.