Heatpump vs. Standard AC

Safari Tim · 01-30-2007, 04:58 PM

I'm trying to decide on an AC for the Ambassador.

I could either go with the heatpump that is also a 13.5kbtu air conditioner. The heatpump will provide heating to around 40 degrees outside.

Or I can go with the 15kbtu with a heatstrip.

Is the extra 1500btu worth it over not having the heatpump? Or should I go with the heatpump so I can save on propane when we have full hookups?

silverback · 01-30-2007, 06:01 PM

Tim,
We went with the 15K BTU unit in the 28' because we live in AZ. I believe ours also has the heatpump as we have the digital wall thermostat with different modes. We do a lot of winter camping and have not used the heatpump (yet). If you're planning on visiting the southwest in the summer you may want the 15K unit for the 28'.
-KL

jdalrymple · 01-30-2007, 06:04 PM

I have the heat pump. It works great until you really need heat, then it just blows cold air. I would say get the electric strips. The other side of the coin is you need to run the furnace some to keep plumbing and tanks from freezing in the belly pan. I have made that mistake too. Live and learn.

str8strm · 01-30-2007, 06:06 PM

the heat strip on our AC does not do much, I think you feel cooler with all the air circulation!! We have furnaces in the MoHo and ran them almost non stop (for the first time) at the 29 palms rally earlier this month---it got down to 18 degrees. We would not have done well with only the heat strips. Of course we were on full hookups and could have used a small space heater to augment the heat strips. As noted above the furnaces kept all the internal plumbing from freezing, our outside hoses froze the first night so we went to using tank water.

Pick · 01-30-2007, 06:15 PM

I have a Carrier heat pump for our house, (60,000 BTU) It kept our house warm last night down to 25*F. It has a built in 5 KW heat strip, but we seldom use it.

The heat strip in our Coleman really doesn't provide much heat at all.

SafariSS · 01-30-2007, 06:24 PM

I have a DuoTherm(Dometic) 15k AC w/heat pump. I have found the heat pump to work ok down to about 45F. My main thing is I dont like the condensation that it produces when running in heat pump mode as I like to keep the outside of the trailer clean! During AC mode the condensate runs out the little tube in the wheel well.

Does anyone know if running the Heat Pump down really cold will cause icing on the condensor?

Pick · 01-30-2007, 07:01 PM

Quote:

Does anyone know if running the Heat Pump down really cold will cause icing on the condensor?

Yep! It does! My home unit has a "defrost mode". Actually all it does is go back to normal air conditioning mode for a few minutes to clear the ice off.

Silvertwinkie · 01-30-2007, 07:04 PM

I also have the 15k A/C with heat pump. I use both and for a 28' Airstream, heat pump issue aside, 15k is the smallest you want to go with. I know some folks will disagree, but back when it was not common, I special ordered our unit with it. Today, many of the 27' footers commonly have it. It does cool very well, even in direct sunlight, or at least it does on my 25' Safari.

I recall several folks trying to talk me out of it, even some folks at the dealer. They said:

"It's only 25' and it's not a standard option for the Safari."

I said "I know and if it's an option for the 25' Classic which has the same specs, then it's good enough for the Safari."

One of the best additions to my Airstream I made, right next to getting the second Fantastic Vent.

Dry heat, humid heat, it doesn't cycle as much as folks said it would and cools perfectly....those who see me at the Midwest Rally know I can get it cold enough to hang meat inside.

lewster · 01-30-2007, 08:26 PM

That's how heat pumps work. There is a reversing valve in the suction line that reverses the flow of refrigerant to turn the evaporator into the condensor, and the condensor into the evaporator. This causes the usually warm air that gets discharged from the condensor to the outside to flow across the evaporator and then into the trailer.

They are not very efficient below 50* and just don't seem to throw much heat at that temp or below. Neither will a heat strip. The furnace is noisey, but it will surely give you the most bang for the buck, considering the much larger transfer of BTUs that they will produce.

That said, the heat pump WILL take the chill out of a cool-ish morning without running the furnace and it's associated noise....and they are only about another $100 or so over the standard A/C unit.

Safari Tim · 01-30-2007, 09:18 PM

Cool. For some reason I thought the heatpumps only went up to 13.5kbtu.

So it looks like the 15kbtu with heatpump is the way to go then. No downside to the heatpump?

Silvertwinkie · 01-30-2007, 09:20 PM

Quote:

Originally Posted by Safari Tim

Cool. For some reason I thought the heatpumps only went up to 13.5kbtu.

So it looks like the 15kbtu with heatpump is the way to go then. No downside to the heatpump?

Not unless it gets under 50 degrees outside. Like Airstreams and tow vehicles, few downgrade.

2toomany · 01-31-2007, 05:29 AM

Only from my past experience with a carrier 15kbtu mounted on a 73 safari camping in the southeast, winters are very mild but offer great camping weather. The carrier will keep you warm to about 38 degrees and will still work below that but, the temp in the trailer will also start to decrease, this is where your furnace or alternate heat source is helpful. Very rarely do we ever camp for extended amounts of time below 38 degrees, but there again it rarely gets below 38 on a continious basis in the southeast. Hope this is helpful

Pahaska · 01-31-2007, 07:05 AM

I keep hearing that heat pumps don't work under all kinds of temperatures; 40, 45, etc., even 50 degrees according to Silvertwinkie.

It's odd that this morning, in the mid-30s, I had to turn the thermostat down a bit because it was too hot in the trailer. I had it set at 72 and it was cycling, so I turned it down to 69.

In 4 years of owning heat pump-equipped Airstreams, I have only had the furnace switchover occur about three times and, those times, I also had frozen water hoses.

The output from a heat pump is not very hot, but it is warmer than the intake air and will keep the trailer plenty warm. While I use a ceramic heater to help initially warm the cold-soaked trailer, the heat pump keeps the trailer warm to near freezing.

**moosetags** · 01-31-2007, 07:21 AM

Our 13.5k heat pump works great for us. We use it almost exclusively to heat Lucy. We have camped in Lucy with nights in the 30's for about 30 nights, and have found that the heat pump is all we need.