Basement Air - Roasting in Florida

[Mooneypaul]

Today it is 81 degrees outside and it is 81 degrees inside with the air on since last night when the temp inside got down to 72 (setting on the thermostat). I have replaced the filter with the cheap low restrictive type. I have turned on the generator and verified that both AC circuits are engaged (using the EMS). The air coming out of the vents is cool but it can't seem to keep up with the outside temp. I have outside sunscreens on the windshield and both front windows. I have the awning out and have all the shades down.

How can I determine if the AC is working properly or is this the best it can do while parked? What have others experienced under similar conditions?

[Mooneypaul]

Today it is 81 degrees outside and it is 81 degrees inside with the air on since last night when the temp inside got down to 72 (setting on the thermostat). I have replaced the filter with the cheap low restrictive type. I have turned on the generator and verified that both AC circuits are engaged (using the EMS). The air coming out of the vents is cool but it can't seem to keep up with the outside temp. I have outside sunscreens on the windshield and both front windows. I have the awning out and have all the shades down.

How can I determine if the AC is working properly or is this the best it can do while parked? What have others experienced under similar conditions?

[Dmadzia]

The air coming out of the closest vent to the A/C unit should be 15-20 degrees colder than room temperature after the unit has been running for aboout 20 minutes. If it is not, you have a problem in one or both of your compressors or somewhere else in the system. I would check the thermostat first as that is the easiest and cheapest part to fix.

[ruppr]

Moonypaul,
In Texas our basement air keeps the rig at 76 degrees when the outside is 96-100. You've got a problem with your unit.

Best,

[mis3s]

Our rooftop A/Cs keep our MHs confortable when we go to the Colorado River (California/Arizona state line) even when the temps are above 100F during summer. Sightseer has dual rooftop A/C. Minnie has single.

Relax, drive safely, and enjoy God's creations.

[John_Canfield]

Running on generator with both compressors active, blower on high, you should be pulling about 21 or 22 amps.

Check to be sure you don't have some kind of duct separation on the output of the blower - this has been a bit of a problem in the past. If you feel cold air around your back cap (if that's where your duct runs), then there is a problem.

As other have said, you do have a problem of some kind.

[DancinCampers]

Not sure if yours is set up like mine, but I would physically look at your indoor coil to make sure it is clean & not plugged up. I can see mine with the filter removed using a flashlight.

Also, check and make sure the side air return grill on the bed is not plugged.

[FrontRangeRVer]

Is your compressors running? I had problems with the compressors shutting down when the outside ambient temperatures drop below 70 or so and I had to move the thermister switch to the INSIDE of the coils....lots of Winnebagos with basement air were wired like this, and I guess people just didn't like it cold inside (like we do). HERE was my post, problem, and solution.

Otherwise, WInnebago insulation is subpar/average and our next motorhome will have MUCH better insulation and a Winter package. During 100 degree temps, our unit can cool the inside down to low 80's, and while that is acceptable to some, it is not to me. Luckily, we don't stay in temps that high, that often.

Oh and by the way....I can feel around on the OUTSIDE of my rear cap and feel (the cooler areas) where the ductwork is running up the rear of my coach, and YES that area is cooler to the touch...doesn't mean that the rear duct work is leaking though, and as far as I can tell, my rear duct work is not leaking as I can't feel cold air when I reach my arm up between the rear cap and rear wall of the motorhome.

Our air temp coming out of the vents is about 20-25 degrees cooler than the return air.

[RKL2]

suggest you clean the outside fins with simple green and a hose....if they are dirty, you will not enough cooling transfer etc....I clean mine twice a season while snowbirding and you would be suprised how much soot like material washes out....
I also remove the inside filter and blow into the opening with a leaf blower to clean the inside fan...this also blows alot of soot like stuff out of the bedroom vents...after doing both, the system works well...also check the taping of the ductwork by reaching up under the rear of the coach.....RKL

[NeilV]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Mooneypaul:
Today it is 81 degrees outside and it is 81 degrees inside with the air on since last night when the temp inside got down to 72 (setting on the thermostat). I have replaced the filter with the cheap low restrictive type. I have turned on the generator and verified that both AC circuits are engaged (using the EMS). The air coming out of the vents is cool but it can't seem to keep up with the outside temp. I have outside sunscreens on the windshield and both front windows. I have the awning out and have all the shades down.

How can I determine if the AC is working properly or is this the best it can do while parked? What have others experienced under similar conditions? </div></BLOCKQUOTE>

I was just out at the beach with temps in the 90's running on a 20 amp service (one compressor turned off) and was able to maintain my set point of 76 degrees. You should be able to do much better running on a full system so something must be wrong.

Mine was not working very well when I first got it due to dirty coils. The cheap filter may make it worse by allowing more dirt to plug things up more completely.

I can inspect and clean my inside coil when changing the filter. I use a round ball style toilet brush (no wire core and has never seen a toilet bowl) and an airesol can of self rinsing coil cleaner twice a year.

I live in Florida and have toured many a new 38J on the LazyDays lot in Sefner when it was near to 100 degrees out. They would cool down almost instantly and within fifteen minutes be tolerable. Within a half hour they would be in the 70's inside from a dead start at over 100 degrees inside the coach.

Also to consider is the damper that switches over from heat to AC that exists on some models. Some have mentioned that this can get stuck midway and cause reduced cooling too.

The past few weeks we have been having low voltage problems from the main power grid here in Central Florida and this can also reduce the output of you AC system. My UPS on my PC shut down the system this morning because the batteries had run too low trying to deal with the extended brown out.

I have an Autoformer in my rig to bring the voltage back up to spec during brownouts and am considering looking into something similar for the house.

[FrontRangeRVer]

There have been lots of posts of barely adequate basement air cooling of the larger units (35'with 3-slides and up), and Winnebago is well aware of this. Several posters have installed a secondary roof air. I personally won't go that route as my basement air is adaquate...but barely.

Let me know about the compressors running issue I asked you about. I have a feeling your thermister switch is cutting off the compressors when the outside ambient temperature falls below 70 or so (even though you have your thermostat set below this figure).

During the day, make sure you cover the front windshield area as that is a HUGE heat gain, and also use your awning if the Sun is on the side.

[wagonmaster2]

With all the postings about moving the thermister in order to keep the cooling compressors running with a low outside temperature (65-75), has anyone been able to determine what it takes to move the thermister to the inside? Is it as simple as moving the refrigerator thermister or does the whole unit have to be dropped down?
Wagonmaster2

[FrontRangeRVer]

No dropping....just pull it out and move to the inside.

[Hitchhiker]

At one of our rallies, another member with a basement air had a bad compressor starting capacitor on his that caused a similar symptom. After it was replaced, the bad one was physically swollen up making it visually obvious something wasn't right with it.

You might want to look at them, if one is swollen up it could be your culprit.

[GaryKD]

Hi wagonmaster2,
My rear bedroom thermister is on an outside wall. This means I can not move it because the wiring is not accessible. I purchased a new thermister. It come with its' own wire. At the A/C unit I disconneced the original equipment thermister. I ran the new thermister into the rear bedroom. It took several temporary placements of the new thermister to determine where it works the best, for us. Once found is was a matter of running the wire so it is hidden.

The original thermister remains in place, just disconnected.

[Mooneypaul]

I took the filter off and used a flashlight but I cannot see the inside coils. Perhaps mine is different on the 38J. I have a surge that displays the voltage and amps and they both seem in line.

[AFChap]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">is this the best it can do while parked? </div></BLOCKQUOTE>
Definitely not! Right now my thermomter is showing outside temp at 92 and thermostat is showing inside temp 76. With the unit running, my infrared thermometer shows outlet air at mid to high 30's (that amazed even me!!). We have maintained inside temps in high 70's in over 100 sunny outside temps.

I've never had a problem keeping the ac unit running in "low" outside temps of 65-75 -- actually don't know that I've tried to run it much in those temps, but have never had it fail to run when wanted.

In other complaints about problems with cooling with our basement units, the normal problem is normally separated duct work behind the rear cap, and/or one compressor stage failing to run. The only time we had a problem, it was the start capacitor for the second compressor stage that was burned up along with a bit of wiring -- the tech said it was likely due to low voltage. That's when I bought a SurgeGuard.

Gary -- Sounds like you are talking about adding a new thermostat rather than thermister. I believe the thermister would be on the other end of that wire in the ac unit itself -- but then you aren't talking about a Winnebago coach with basement air either. However, the point of thermostat placement affecting heating/cooling is one I have considered. Our thermostat (one central 'stat controls the dual compressor basement air/heat pump unit) isn't badly placed, but some do get extraneous heat from appliances, etc and can benefit from being relocated.

[Lindsay Richards]

I am sitting in Florida in the low 90's right now and it is cool inside. My actual thermostat temp never has seemed right on heating or cooling, but it cycles the basement heat/air well and we adapt to the obviously wrong reported temp.

[Billy S]

I have been having problems with the basement air, cools good, than it won't cool at all, had the unit checked and the main board has a burned spot, will have it replaced tuesday,hope this is it.

[Mooneypaul]

Thank you all for your suggestions. I checked everything you guys mentioned and still no change. So it is at the shop. I will let you all know what happens.