Operation of second A/C

timmytfl · 06-15-2012, 08:53 PM

This may seem like a silly question, but can anyone explain how the 2nd A/C works. We just got to our RV today in MI after being away for 2 weeks. It was a hot day here (90 degrees) & turned on the main A/C right away. We only have 30 amp service here so can't run 2nd unit at same time as the main one. With the main A/C running the upper bedroom vents had cold air coming out, in addition to air in living room. After a while, we decided to turn off main A/C & try the 2nd A/C. With just that upper A/C running, we still had cool air coming out the living room vents which surprised us. We thought the 2nd A/C was only for the bedroom . Can anyone explain how this all works? Thanks

TravelinAnderson · 06-15-2012, 09:54 PM

You aren't the first to think one a/c is for half the trailer and the other a/c for the rest. Truth is both A/C units service the entire trailer. Running the second a/c just adds more cooling for those extra warm days.

If you don't run other appliances when connected to 30 amp service you can usually run both a/c units. I have done this several times. I just switch my water heater to gas and avoid using other high amperage hogs like the microwave, hair dryer, coffee maker and central vac.

Edited by: TravelinAnderson

timmytfl · 06-16-2012, 05:42 AM

Thanks so much for the clarification! We had been back in FL & when we left here two weeks ago, it had been cold enough here to run the furnace! This was the first time we had even turned the A/C on. When we left here two weeks ago, we should have turned the main A/C on to 80 so it would run occasionally while we were away. Next time we'll do that. Yesterday after it ran four hours, main unit, it only cooled down from 85 inside to 80. When we switched to the second unit, it actually felt colder air coming out of all of the vents. We have the 34 SK model with a lot of windows, so evidently it just took longer than normal to cool down. This morning it's 56 outside & chilly inside so have the electric fireplace running, with A/C off of course! Hey, that's Michigan & so much better than FL in the summer!

TravelinAnderson · 06-16-2012, 07:13 AM

We are in Michigan now as well and experiencing days near 90 degrees and nights in the low 60s. In the evening I switch the main t-stat to "heat" and set the temp to 70. I leave the second t-stat on and set it at 79 degrees. That way the furnace will kick on if it gets too cool at night and the AC will kick on when the day heats up. By mid-day I have to set the main t-stat to "cool" to keep the trailer comfortable.
As you mentioned... It's a good idea to leave the A/C on even if you're away from the trailer because it's easier to keep a trailer cool than it is to cool it down after it gets hot. Once the contents, chairs, couch cabinets...etc..., get warm they radiate heat which makes it difficult to cool things down.

**Dave&Ginny** · 06-18-2012, 04:53 PM

One VERY important thing to remember while trying to cool down your rig in the summer, keep the basement doors closed!

A few weeks ago I was waxing my trailer while it was very hot. I had the basement door open because that's where I was setting my beer and radio. After a few hours I went inside and noticed that the bedroom was very warm even though I had both A/C units going full bore. I saw light comming in under the dresser and realized that there is an open vent between the basement and the bedroom under the dresser. This was allowing the A/C unit to suck hot air into the coach. Once I closed the basement doors, the coach cooled down quickly

RollsRoyce · 06-18-2012, 05:57 PM

Dave did you find that vent by pulling out one of the bottom dresser drawer's or where was the vent closure in the roof of the basement

**Dave&Ginny** · 06-19-2012, 08:32 AM

Quote:

Originally Posted by RollsRoyce

Dave did you find that vent by pulling out one of the bottom dresser drawer's or where was the vent closure in the roof of the basement

Open the basement door and look under the dresser, you'll see the light. It's toward the front of the basement. If you put your hand under the dresser you'll feel the hot air being pulled into the bedroom.

TravelinAnderson · 06-19-2012, 10:02 AM

Dave, you may to let them know what model Redwood you have. I was going to check mine out then realized that you and I don't have the same model trailer.

**Dave&Ginny** · 06-19-2012, 10:12 AM

Quote:

Originally Posted by TravelinAnderson

Dave, you may to let them know what model Redwood you have. I was going to check mine out then realized that you and I don't have the same model trailer.

Well that's a good point but I would guess that they all have a vent going into the basement since they all have heat ducts going in there too. I have a RL, but I believe with the exception of the FL they all should have the same basement. Like I said before though, I'm sure the FL would have a vent somewhere as well.

timmytfl · 07-04-2012, 06:07 PM

How is everyone holding up with this heat across the country? We're in MI where the temps are mid 90s. We have both A/Cs running & only cools down to 80 degrees in our 34SK. We're wondering if we might need more freon. Maybe it's just all of this hot weather?

UNDRPSI · 07-04-2012, 06:35 PM

We just picked up our 36 FL Saturday in Tampa FL. It was 95 degrees out. Both AC's kept up with it Had to turn the back AC down at night wife said it was to cold. I thought it was just right! Told her to move alittle closer

Enroute · 07-04-2012, 07:34 PM

Don't pick up the new 36RL until next week, but I can say that in current 40' Montana running w/ a 15K btu and a 13.5k btu, the inside of the coach is staying a cool 75. Temps outside this afternoon were 104 before heat index. Weather channel said it feels like 113 outside in MN. I'd suggest having your a/c units looked at as 2 15K btu a/c units should be able to get the coach cooler than 85 degrees in a 36' coach. Just my opinion.

**Dave&Ginny** · 07-04-2012, 07:49 PM

I have an RL and what I have found so far is to make sure all of the roof vents are closed, the basement doors are closed and the closet door is closed. Then I don't have any problems at all keeping the unit cool with 2 air conditioners with the outside temperature exceeding the mid 90's.

TravelinAnderson · 07-04-2012, 08:41 PM

We get our A/Cs going in the morning when it's cooler so they can get a head start on the heat. Here in Harpers Ferry, Wv the temp was 97 outside and 77 inside our 36FL. we also run the ceiling fan in the kitchen to circulate the air better.

Tall-Pines · 07-04-2012, 09:43 PM

Not sure if TravelinAnderson is referring to the big 4 bladed "Ceiling Fan" in the Living Room or the Maxxair fan set to "ceiling fan" mode. That would be with the Maxxair fan on and lid closed.

mhs4771 · 07-04-2012, 10:47 PM

We've been able to keep our 36RL in the mid to low 70s with both ACs going. To us the Redwood cooling and heating systems seem to work much better and more efficient than our Montana.

timmytfl · 07-05-2012, 09:48 AM

Thanks everyone for your comments/suggestions. Now we turned on the kitchen Maxxair fan with lid closed & blade turned so it's not trying to pull air up to a closed lid, it's just circulating air, like a regular ceiling fan! We're doing the same with the fan in our bedroom. We're also running only the second A/C this morning, which according to our printed information, is 30k btu, while the main A/C is 15k btu. Where we are here near Evart MI, the forecast is 97 high both today & tomorrow!

Tall-Pines · 07-05-2012, 10:07 AM

Actually the second A/C unit is also 15K BTU giving you a total of 30K BTU when both are operating.

lillyputz · 07-05-2012, 10:34 AM

Quote:

Originally Posted by Tall-Pines

Actually the second A/C unit is also 15K BTU giving you a total of 30K BTU when both are operating.

You're right. the advertisement is misleading.

Lillyputz

**hoosierguy** · 07-05-2012, 09:06 PM

The out side temperture has reached 100 and 101 degrees the past two days. I have been running both air conditioners with the rear unit set to 77 and the front unit set to 78. Theinside temperaturehas not gone over 78 degrees.

I will agree that the front closet really gets quite excessively warm. I think that is because the factory uses fiberglass to cover the curved areas since they can't use the foam board like in the walls. I think they need to develope a spray foam process to get a higher R-factor over the nose of the 5th wheel.

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