A/C Issues??

[Alex_and_Tee]

Brand new coach - 2 months old. In Casa Grande, AZ. Outside temp is 85 degrees. Both front and rear A/C’s are set at 75. Rear of coach is 74, front of coach is 84. All solar shades are down and windshield solar and night shades are down. Front of coach faces generally west.

Do I have an issue with the front A/C unit? Do I need to cover the windshield better?

Appreciate your input.

[dougrainer]

Alex and Tee wrote:
I agree it wasn’t the right thermometer but it measured something at those temps. It was either the vent or the duct behind the vent.

Furnace problem was simple. I turned the front furnace on and the rear one came on. The rear one turns the front one on. However they both still rely on their own respective temperature sensors. So they run on and on because the sensor in the front won’t turn the rear one off.

The front touch control turns on the front a/c and the front heat pump but the rear furnace. The rear touch control turns on the rear a/c and the front furnace.

This is a simple fix on the spyder system. Just swapping the rear and front furnace 2 wires at the spyder module. Doug

PS, SHOULD have been caught at the PDI by the selling dealer.

[Alex_and_Tee]

I agree it wasn’t the right thermometer but it measured something at those temps. It was either the vent or the duct behind the vent.

Furnace problem was simple. I turned the front furnace on and the rear one came on. The rear one turns the front one on. However they both still rely on their own respective temperature sensors. So they run on and on because the sensor in the front won’t turn the rear one off.

The front touch control turns on the front a/c and the front heat pump but the rear furnace. The rear touch control turns on the rear a/c and the front furnace.

[dougrainer]

Alex and Tee wrote:
Doug - thanks for your input. The digital thermometer I used is a Jumper digital thermometer. The “House” symbol indicates object measurement mode. It seems to be accurate with other similar type measurements. The readings I got were taken right at the vent with both a/c’s running. Although this is not perhaps the right tool to use it’s what I had and I doubt it would be 20 degrees off.

I have the mobile tech from La Mesa RV coming next Saturday to fix my reversed furnace wiring and some other things. I will have them check both a/c units while they are here. I would imagine they have a more appropriate measuring device for the application.

My google search of a Jumper Digital Thermometer indicates it is a IR/thermal type Medical thermometer. Which, I stated you CANNOT use. IR thermometers CANNOT sense AIR. They sense solids. Reversed Furnace wiring????? How did you determine that? Not what may be causing your cold problem, just want to know what your furnace problem is and how you determined it is reversed. Doug

[Alex_and_Tee]

Doug - thanks for your input. The digital thermometer I used is a Jumper digital thermometer. The “House” symbol indicates object measurement mode. It seems to be accurate with other similar type measurements. The readings I got were taken right at the vent with both a/c’s running. Although this is not perhaps the right tool to use it’s what I had and I doubt it would be 20 degrees off.

I have the mobile tech from La Mesa RV coming next Saturday to fix my reversed furnace wiring and some other things. I will have them check both a/c units while they are here. I would imagine they have a more appropriate measuring device for the application.

[CA_Traveler]

OP Listen to Doug - He has more experience and knowledge than anyone else on this board that I'm aware of.

[dougrainer]

You have the 2022 Tiffin Open Road? If so, you have a problem. A Tiffin in 85 ambient will freeze you out with 2 AC units. I would set the front at 65 degrees and the rear at 75 and then see what happens. Your Tiffin has the inside temp sensors mounted in the ceiling drivers side next to a cold air vent. 1 in the Bedroom and 1 in the living room. Also, turn the rear OFF and run the front at 65 degrees. Test after at least 1 hour. The air output in the living room should be at least 60 degree output. It will probably be in the 50 to 55 range. Your 42 and 43 are NOT correct or accurate. Your Thermometer is not designed for what you are testing. The Delta difference is 18 to 22 degrees. That means at your 42, the warm INPUT would be 62 degrees which is enough to freeze you out. So, based on my 42 years as a RV Tech (Tiffin dealer tech also), your temp measurements are not good/correct at all. Doug

PS you state digital thermometer set on house mode. NEVER heard of that type thermometer and I would not use such a appliance. Click this link for what you should use. ALSO, you CANNOT use a IR type Thermometer.

https://www.oreillyauto.com/detail/c/robinair/tools---equipment/measuring-tools/thermometers/bbe3c38...

[Sandia_Man]

Sounds like they are operating fine with temps in the 40s coming out the vents, in our class a gasser we have RVed in 100+ temps without issue, we just crank them down to the sixties and let them run until ACs have removed most of the heat trapped within the rig.

With temps in the mid 80s the front curtains and motorized blinds are enough, when temps are 95 and above we will implement our windshield sun shade that we have cut to a perfect fit, it covers entire windshield and front side windows deflecting much of the incoming heat.

Unlike homes, even the best insulated RVs will contain heat that is not as easily dissipated, cranking down AC units and keeping them active throughout the entire day and night is the only way to truly stay ahead, waiting for temps to peak before activating ACs is too late.

[Alex_and_Tee]

Measurements done with a digital thermometer set on house mode. Will invest in some reflective shades for the front window. Front of coach is primarily black so I’m sure that isn’t helping much.

[CA_Traveler]

wa8yxm wrote:

Alex and Tee wrote:
Front measures 42.3 rear measures 44.1 at the roof vent. It is ducted from front to rear. Same fan speed on both. Seems to be equal air flow from all vents. 3 vents in the roof in front, 3 in the rear.

30 degrees delta (Difference) Between inlet and outlet sounds like they are working as designed.

He stated 84 in the front and 42 outlet for a 42 degree difference. This doesn't seem correct to me.

[wa8yxm]

Alex and Tee wrote:
Front measures 42.3 rear measures 44.1 at the roof vent. It is ducted from front to rear. Same fan speed on both. Seems to be equal air flow from all vents. 3 vents in the roof in front, 3 in the rear.

30 degrees delta (Difference) Between inlet and outlet sounds like they are working as designed.

The problem is common especially if you have a dark color scheme (Like mine did) it just soaks up the sun faster than the A/C's can dispose of it.. I upgraded from 13,500 to 15,000 BTU both ends and it still got hot.

[rgatijnet1]

If you can see behind the cabinets above the dash you may find that the manufacturers only used fiberglass insulation, which tends to sag. This means that a lot of heat/cool is lost through the front cap. I used spray foam to insulate that area and it helped a lot, especially during the Winter when I used to get condensation dripping from behind the cabinets.

[wildtoad]

If you’re parked in direct sun and the front ac is pumping out 42 degrees it’s doing about all it can do. You might try setting up a fan to better distribute the cooler air from the rear to the front. Not sure what type of shades you have but you may want to investigate better reflective type shade material.

[chuckftboy]

You say both are set to 75 and the rear is 74. That means the rear is cycling the compressor off because the temp is satisfied and the compressor is cycled off. Just leave the front set to 75 and bump the rear down to 68. You need both running to drop the temp up front where all the glass is. At night you can bump the rear back up because you won't have the sun load on the front of the coach.

[CA_Traveler]

Alex and Tee wrote:
Front measures 42.3 rear measures 44.1 at the roof vent.

You lost me - are these degrees F?

BTW I think ceiling vents are the more common terminology.

Plus for checking the in/out temps as I suggested run only one AC at a time since the ducts may be common to both. And if you can change the outlet air directly from the AC vs the ceiling vents do so for the checking the temps.

[CA_Traveler]

Apparently front AC is not working. Turn down the temp to 65, fan running on auto or high, correct settings, can you hear the compressor running vs just the fan?

The outlet temp should be 20 degrees less than the inlet temp and if so you have other problems.

An additional test would be to set the rear to 65 in order to understand it's capability when it gets hot outside. And yes windows and especially the large west facing windshield can a concern in the SW but not so much at 85.