A/C Edumacation required

osgoor · 09-25-2014, 06:43 PM

Hi all,

I have a 2005 Itasca Suncruiser 37F and am now in hot hot Mesa, AZ. The A/C runs 24/7 but never cools below mid 80's. I see conversations about 2 compressors but am not sure what I have. My questions are, is this a normal cooling capacity when temps are 100 or more?, Do I have 2 compressors? Is it possible to re-charge the A/c myself? If so, is their a pdf on where/how? I have done my cars before so feel ok with handling it.

Thanks

emiddleb · 09-25-2014, 07:15 PM

osgoor,

Lots of Qs, I'll try to answer some... looking at the brochure for your model, you have essentially the same basement air I have.

The unit has two compressors built-in to it. When turning on you should hear the first one kick in, the second one 15-30 seconds later. The AC owners manual has all the info on when/what turns on, I won't repeat it all here.

The unit is sealed, there is no recharge ability.

A 20-degree drop is pretty much in range for the basement AC. I've seen a couple threads about owners in high-heat areas replacing one of their square ceiling vent fans with a roof AC unit to add cooling. Not trivial, requires running power etc. See this thread as an example...

http://www.irv2.com/forums/f101/supp...dding+roof+air

One thing you might check... many have reported a separation of the ductwork in the rear of the RV where the duct runs from the basement AC to the roofline. While the AC is running try to feel up under the back cap to see if you have any cold air coming out there, which would indicate a leak.

Hope this helps.

KIX · 09-25-2014, 07:24 PM

Your basement unit should drop the air temp by 20 degrees from the return air temp (not outside ambient temp). If your not seeing at least an 18 degree drop across the evap coil the coil could need cleaning or the filter may need to be cleaned or renewed.
Google Airxcel / RVComfort and snoop around their site to get the service manual for your unit. The manual will advise how to ascertain that the #2 compressor is coming on.
Heat gain through the walls and ceiling is hard to do anything about but the windshield and windows heat gain can be reduced by covering them. Hope all this helps you get below 80.

osgoor · 09-25-2014, 07:59 PM

Thanks... We have changed the filter located under the bed. This was a 14 x 20 filter. I assume this is the correct filter to replace. I also looked at the coils at the rear (passenger side) and it looked clean... I can blow air through that t see if it is really clean. I will also feel underneath for a cold air leak... How do you open the cover to the air conditioner?

As far as the compressors, When I turn on the A/C, it takes about 10 - 15 seconds before I hear a single click and then the air comes on. There is no second click. Is there an easy way to confirm both compressors are coming on line?

Thanks again

Harry B · 09-25-2014, 08:24 PM

Run the A/C while operating from your generator. The ampmeter on the One place panel will show about 24 amps when both compressors are running and about 14 amps with only 1 compressor running and fan speed on high.

That meter only indicates amps while the generator is operating or when you are plugged into a 30 amp shore power source. It will not indicate while plugged into a 50 amp service.

osgoor · 09-25-2014, 08:31 PM

Quote:

Originally Posted by Harry B

Run the A/C while operating from your generator. The ampmeter on the One place panel will show about 24 amps when both compressors are running and about 14 amps with only 1 compressor running and fan speed on high.

That meter only indicates amps while the generator is operating or when you are plugged into a 30 amp shore power source. It will not indicate while plugged into a 50 amp service.

Will do and thanks

1ciderdog · 09-26-2014, 10:12 AM

Quote:

Originally Posted by KIX

Your basement unit should drop the air temp by 20 degrees from the return air temp (not outside ambient temp). If your not seeing at least an 18 degree drop across the evap coil the coil could need cleaning or the filter may need to be cleaned or renewed.
Google Airxcel / RVComfort and snoop around their site to get the service manual for your unit. The manual will advise how to ascertain that the #2 compressor is coming on.
Heat gain through the walls and ceiling is hard to do anything about but the windshield and windows heat gain can be reduced by covering them. Hope all this helps you get below 80.

Just to add to what Kix says: place a thermometer at the air return intake, near your air filter or on it and after a few minutes put that thermometer at one of the cold air returns. The air coming out should be about 20 degrees cooler.

I don't think you can get to the compressor area without pulling the air conditioning unit. At least that's the way it is on mine. There is a small panel you can remove that gives you access to the circuit board and capacitors.

KIX · 09-26-2014, 10:52 AM

What u see from outside is condenser cool. You must remove unit to clean EVAP coil

KIX · 09-26-2014, 11:07 AM

Look under compartment door for 2 screws and on next comp door jamb area for 3 screws

Arch Hoagland · 09-26-2014, 11:14 AM

A lot of heat comes through the windshield. Do you get full sunshine on the windshield?

I carry an external mask for the windshield which helps cut back some heat and keep the windshield curtains pulled during the day.

SuperGewl · 09-26-2014, 08:07 PM

Quote:

Originally Posted by osgoor

Thanks... We have changed the filter located under the bed. This was a 14 x 20 filter. I assume this is the correct filter to replace. I also looked at the coils at the rear (passenger side) and it looked clean... I can blow air through that t see if it is really clean. I will also feel underneath for a cold air leak... How do you open the cover to the air conditioner?

As far as the compressors, When I turn on the A/C, it takes about 10 - 15 seconds before I hear a single click and then the air comes on. There is no second click. Is there an easy way to confirm both compressors are coming on line?

Thanks again

There are 2 filters under the bed so if you only replaced 1 then go back and check again.

osgoor · 09-26-2014, 09:20 PM

Quote:

Originally Posted by Arch Hoagland

A lot of heat comes through the windshield. Do you get full sunshine on the windshield?

I carry an external mask for the windshield which helps cut back some heat and keep the windshield curtains pulled during the day.

Yes, we face NE and have a windshield cover and keep the curtains pulled.

osgoor · 09-26-2014, 09:22 PM

Quote:

Originally Posted by SuperGewl

There are 2 filters under the bed so if you only replaced 1 then go back and check again.

Under the bed in our rig there is only one filter. It is a 14 x 20 size and is located in the lower left corner of the bed frame. Where would I find the other filter?

osgoor · 09-26-2014, 09:23 PM

Quote:

Originally Posted by KIX

Look under compartment door for 2 screws and on next comp door jamb area for 3 screws

A bit confused... do I need to remove the entire A/C unit to clean the coils? That would not seem to be a good design.

KIX · 09-27-2014, 12:55 PM

Quote:

Originally Posted by osgoor

A bit confused... do I need to remove the entire A/C unit to clean the coils? That would not seem to be a good design.

YES, you need to remove the unit to clean the inside of condenser coil and both sides of the evaporator coil. You can see one side of condenser coil from outside the coach. The coil that can affect cooling ability is the evaporator coil. That's the one that requires the unit is out of the moho to clean it. The motor shaft bearings need to be lubed while you have it out Be very careful to not bend the fins on the coils. If your evap coil hasn't been cleaned since coach was new (2005?) I can just about guarantee that it needs to be cleaned.

1ciderdog · 09-28-2014, 06:13 PM

If you are mechanically inclined you can pull the generator yourself. Probably best to have a helper but I pulled mine and cleaned it a couple of months ago without help. There are a couple of threads on this site about pulling the basement AC unit and they are very helpful.

Duner · 10-03-2014, 07:00 AM

osgoor,

I've worked on my A/C a couple of times and documented a procedure for pulling the unit out and doing some basic repair inside the unit. Many forum members have found it very useful & have repaired their own unit.
Here's a link to download

To help you get further progress, need to know these...
What temp differential did you measure (air at intake filter vs vent output)?
What currents are you seeing on the PowerLine monitor?

Good luck,
Bill

t55watson · 10-03-2014, 07:12 AM

Something not mentioned is the fact that you must be hooked up to 50 amp service for both compressors to run. If you are on 30 amp service the 2nd compressor will never run.

wackymac · 10-03-2014, 07:25 AM

Another thing to consider is the exterior color of the coach. White will be easier to cool than dark colors because white will reflect more heat.

Wizard · 10-03-2014, 07:25 AM

Quote:

Originally Posted by t55watson

Something not mentioned is the fact that you must be hooked up to 50 amp service for both compressors to run. If you are on 30 amp service the 2nd compressor will never run.

Mine runs quite well on 30 amp service. The powerline monitor controls what else will run at the same time by dropping out things like water heater and second compressor when the amps exceed 30. With both compressors running I draw about 24 amps.