Air conditioning efficiency

[Jim27]

I am having some issues properly regulating the temperature in my trailer. My air conditioner is located in my kitchen which is at the opposite side of the living area from my temperature sensor which is located on the wall by the stairs leading up to my bedroom. I have been setting the thermostat at 75 and the ac would never stop running. I realized that the air in the trailer felt much cooler than the thermostat was reading so I got a temperature gun. The air in the living area was down to the desired 75 but the temperature at the sensor was still 80 degrees. Do I need to “fool” the thermostat by setting it at 80 in order to maintain the desired temperature of 75? Also does the ac work better by dumping all of the cold air into the kitchen or by closing the dump and allowing the cold air to come out of the three vents located throughout the ceiling in the living area?

[sourdough]

Jim how many ACs does that Raptor have? Also, where are you at and what is the outside temp? Do you have InCommand or digital thermostat(s)?

[Jim27]

Originally Posted by sourdough

Jim how many ACs does that Raptor have? Also, where are you at and what is the outside temp? Do you have InCommand or digital thermostat(s)?

The Raptor has 3 ac units and I am in Texas where the outside temperature is currently 80 degrees. The ac is blowing at 63 degrees and just won’t cool down the temp enough to stop running. I have InCommand.

[chuckster57]

Placement of the sensor can be critical. Do you know where they are in your unit? They are small and look like this:

https://www.rvupgradestore.com/Colem...036d8ffd8ca2b5

If you have 3 zones, then there should be 3 of those, usually in the ceiling. I would make sure they are hooked up correctly. I’m not sure what the testing protocol is.

[Jim27]

Originally Posted by chuckster57

Placement of the sensor can be critical. Do you know where they are in your unit? They are small and look like this:

https://www.rvupgradestore.com/Colem...036d8ffd8ca2b5

If you have 3 zones, then there should be 3 of those, usually in the ceiling. I would make sure they are hooked up correctly. I’m not sure what the testing protocol is.

Hey Chuckster. I recently had the main ac unit replaced and it is currently blowing at 62 where my bedroom unit is blowing at 52. My sensors are not the same as the picture that you sent but I will attach a picture.

[chuckster57]

That may be just the fancy cover...anyway, RV air conditioners are considered to be within specs if the exhaust air temp is 20 degrees colder than the intake air.

[Jim27]

The ac has been running for hours and blowing at 62. The sensor on the other side of the room near the iN·Command is reading at 81. I know that the sensor is reading properly because when using the temperature gun I’m getting a reading 81.

[chuckster57]

It is on an interior wall, right? No direct sunlight?

[Jim27]

Originally Posted by chuckster57

It is on an interior wall, right? No direct sunlight?

Yes. It’s on the wall directly above the iN·Command on the stairs to the bedroom.

[chuckster57]

I’m wondering if you have vents in the ceiling that you can turn? If so have you tried aiming them in different directions?

Toy haulers are notorious for having high ceilings, is your outside a dark color? I’m thinking maybe the walls are absorbing heat.

[Jim27]

Originally Posted by chuckster57

I’m wondering if you have vents in the ceiling that you can turn? If so have you tried aiming them in different directions?

Toy haulers are notorious for having high ceilings, is your outside a dark color? I’m thinking maybe the walls are absorbing heat.

You nailed it. I closed the main dump which ducted the air through the ceiling vents. I then realized that the the ceiling vents are directional so I turned the vent closest to the thermostat in the direction of the thermostat and it immediately started to lower the temperature at the thermostat. Also my rig is black. Another mistake that I may be making is that I am keeping my blinds all the way up in order to let light into the trailer. I’m in Texas with no tree cover and I’m in direct sunlight all day. I don’t want to feel boxed in but I assume now that I should probably keep them down?

[chuckster57]

I have often told customers with dark exteriors that it might be better to eat breakfast in a parka so dinner will be comfortable. Start your AC early.

[Jim27]

Originally Posted by chuckster57

I have often told customers with dark exteriors that it might be better to eat breakfast in a parka so dinner will be comfortable. Start your AC early.

Lol. My iN·Command has a timer so I’ll set it to cool off early. I’m also going to keep my blinds down to keep the sunlight out. Thankfully I’m spending the summer in PA so I won’t be dealing with the brutal TX summer heat. Thanks again for your help, it’s been invaluable.
Jim

[Camping family]

Are you running all 3 ac’s or just the one in the kitchen. If only running one try running all 3. Setting them at the temp,you desire in each zone

[Jim27]

[QUOTE=Camping family;446271]Are you running all 3 ac’s or just the one in the kitchen. If only running one try running all 3. Setting them at the temp,you desire in each zone[/Hey Bob.

I was trying to cool the whole living area by running only the main living area ac. After a stressful, sweaty day and plenty of helpful input on the forum I’ve established that I will need to run two ac’s in order to beat the Texas sun! Thanks for your advice!
Jim

[bobbecky]

Another thing to check is, if you can get the thermostat off the wall, and this might be one of your sensors also, check behind that thermostat for a large hole. If there is a large hole where the thermostat wire goes through to connect to the thermostat, try to pack insulation in the hole and or tape over the hole around the wire so warm air in the wall isn't making the thermostat warmer than the air in the room.

[Jim27]

Originally Posted by bobbecky

Another thing to check is, if you can get the thermostat off the wall, and this might be one of your sensors also, check behind that thermostat for a large hole. If there is a large hole where the thermostat wire goes through to connect to the thermostat, try to pack insulation in the hole and or tape over the hole around the wire so warm air in the wall isn't making the thermostat warmer than the air in the room.

Ok I will definitely check that. Thanks again!

[Wyldfire]

Best thing we did was retape the inside of the air conditioner. Factory did a lousy job. reference. AC was going into attic than RV. You tube video for referance.

https://youtu.be/cct1QfLiT6s

[Jim27]

Originally Posted by Wyldfire

Best thing we did was retape the inside of the air conditioner. Factory did a lousy job. reference. AC was going into attic than RV. You tube video for referance.

https://youtu.be/cct1QfLiT6s

Thanks for the info. I’m not the best DIY guy and am a little sketchy on disassembling my ac especially where it connects to the roof. I’m headed to PA in June and my best buddy is a mechanical engineer who can basically fix anything. He already has me making a list of things for him to upgrade. I will show him this video and also some other ones about “turbocharging” rv ac units. By the time he’s done I will probably be making ice cubes on my kitchen counter! I’m currently at a park with free electric and only here in Texas for one more month. For now I’ll just run on two ac’s until I get to PA then let the upgrades begin. Thanks again for the info!

[LHaven]

I have to say, locating the thermistor directly above a piece of heat-generating electronic equipment would not be on the table if I were the RV designer. Even moving it off to one side would be a big improvement. Mine is on an interior wall, but two-feet opposite the door glass, which is trouble enough.

The dump louver is designed for rapid cooling of a single area, not for general operation. When we come off the highway and set up camp, the inside of the rig is usually pretty hot -- we open the dump louver, let the central room cool down fast, and work in that area until we stop sweating; then we close it to even out the temperature all over the rig and leave it that way until we hit the road again.