Temperature Differential Expected

[JimGolden]

Hi Everyone,

What is the normal temperature differential I should expect from my Airstream's roof unit? I've got the original unit on my '77 Excella with the heat strip. When it's 30 out, it'll heat it up to about 55 in there. Likewise the a/c unit will cool it down to about 75 when it's 90 out. I'm thinking it should work a little stronger than this? What's normal?

Thanks,

Jim

[wahoonc]

Jim,
Dunno about the heat strip but that sounds about right for the A/C. It will also depend if you are in full sun, awnings deployed or not, curtains drawn...etc. IIRC the unit is only 13.5k btu's not really strong enough to cool a unit like an Airstream in full sun. There has been quite abit of beefing in the past about this very issue on the newer Airstreams. Most owners end up upgrading to the 15k units or in some cases install a second unit in the rear vent.

Aaron

[ALANSD]

On our 82 Motorhome (28 footer) the roof unit wiull heat the interior to a comfortable range only if the outside temp is no lower than 40. I use the furnace when it drops below that level, although now I am considering using
a ceramic type heater in addition to the heat strip for safety. I always worry a bit about a 25 yr old furnace. Even though I have had it out and worked on it to keep it running well.

[dwightdi]

I have a 31 foot 1977 unit also. It was above 100 at the Rapid city International both years we were there. No 30 amp so that is the temperature it got inside the unit. The second time we were there I had painted the top of the unit white like the newer Airstreams and that reduced the temp inside by 10 degrees. I would suggest, if you think the unit is too hot with the air conditioner running in full sun, you consider painting the top of the unit with high gloss white enamel and keep all the awings down. It does not look bad from eye level and is hardly noticable. It would cost a lot less than buying a new air conditioner. Most of the southern California units do it.

[sander17]

Most air conditioners in houses are designed to have a 20 degree
differential between the intake and the output vents in the house.
Any colder than this and it is uncomfortable to be near a vent and
you also risk frosting up the coil. When that happens, you get no
air flow and it runs away to a totally plugged up condition.
Put a couple of thermometers at the two openings to see what the
differential is. Don't use the ambient temperature at the thermostat.

A few weeks ago I tried to use the heat pump in our recently acquired 96 Excella, but no heat came out. Then I discovered that it has an internal thermostat that disables the heat pump if the outside temperature is below 45 degrees. I tried it again when it was 55 and it worked ok.

Good luck with your air conditioner.

[SafeHarbor]

Hi, Jim,

I have a 79 31' with the Armstrong 13.5 btu A/C with heat strip. I'm very happy with the job that it does in cooling. With three awnings out and the rock guard down, the trailer can be kept below eighty degrees when it's over a hundred outside. I imagine it could get it down to seventy if I wanted to.

The heat strip can keep it in the mid-seventies inside down into the mid-fourties. In really cold weather (such as it gets in Deep Dixie), I run the heat strip with the furnace set to come on at sixty-five. A couple of weeks ago, it was thirty-one degrees here. When I got up, it was seventy-two degrees in the back bedrom according to the digital wall thermostat I put in for the furnace (a Hunter unit for less than $20). I went into the kitchen, got on my knees, and felt the heat duct. If the furnace had run at all during the night, it was already cooled by the time I got up.

For about a week since then, I've left the thermostat in the same place for the A/C, switching it to cooling about 11 AM and back to heat about 7 to 8 PM. I like to keep it around 78. Right now it's 64 outside, 75 in the front of the trailer, 78 in the bedroom, and I have not switched to cooling yet today. It's supposed to hit the seventies by this afternoon, but we have cloud-cover, so I think I'll just be opening some windows.

Lamar

[JimGolden]

Thanks for the replies. Sounds like my old unit is working about par for the course then.

I haven't tried the furnace yet. Just got the trailer about three months ago and it had no LP bottles on it. Still waiting to get the title for it and so am not putting much $$$ into it until that happens. It's been down into the lower 30's where I'm at and the heat strip would get it to about 55. Not bad with a jacket on, but a little cool for my tastes. I'll need to get the furnace checked out.

Thanks,

Jim