2016 Thor Motorhome A/C Expectations?

[nwood488]

We have a Majestic 23A and parked on some family land with full hook ups. We are experiencing 90-98 heat right now in Kentucky. We have very little shade unfortunately. The past few days the A/C won’t get much below 77, even on high. It wasn’t like this when we first got here and experiencing similar heat around 90. We would come in at night and it would be 74 and sometimes slightly cooler.

Does this sound normal?

[EA37TS]

Originally Posted by nwood488

We have a Majestic 23A and parked on some family land with full hook ups. We are experiencing 90-98 heat right now in Kentucky. We have very little shade unfortunately. The past few days the A/C won’t get much below 77, even on high. It wasn’t like this when we first got here and experiencing similar heat around 90. We would come in at night and it would be 74 and sometimes slightly cooler.

Does this sound normal?

Delta T should be around 20 degrees. Outside temp has no bearing. K

[DavidEM]

To expand a bit on EA37TS' point above: with an IR gun, measure the cold air temp coming out of the AC and the room air temp being pulled into it. The difference should be at least 20 deg F.

If you get that difference your A/C is doing fine and if it won't keep up it is too hot for it outside.

David

[Judge]

You also need to do more than just run the A/C..... once you verify the temperature differential between air entering the A/C and the air exiting the A/C has a difference of 16 - 22 degrees. A digital thermometer works great because you can stick the probe into the intake and exhaust vents in the A/C unit.

- Purchase the WeatherTech Full Cab Sun Shade Kit and install it every time you stop to keep the sun and heat out of the cab by covering the windshield and door windows. If you don't give those windows it will be a losing battle.

- Close all window shades.

- Pull the curtain over the cab-over bunk. If you don't have a curtain, make one. There is no insulation in the front cap and it can generate a lot of heat that makes its way into the living areas.

- Don't wait for it to get hot to do all of the above and run the A/C. The sooner you start the better chance you have for beating the heat.

- Then if you want to get "fancy" you can climb on the roof and insulate the evaporator enclosure and a few other tricks you can read about on the forum.

[JimOIB]

To add to Judge’s comments related to heat gain, put pillows in the vent openings in the roof since they directly bring heat into the coach. Also, if you have a slide then close the gaps between the slide floor and the coach floor. This 1 to 1-1/2 strip can cause the A/C to draw warm air in from the outside. Go to your fav HW store and get some foam pipe insulation the size of the gap and stuff it in.

One simple overlooked item is cleaning your A/C filters - with heavy use the filters get dirty fairly quick. It will make a big difference on airflow.

[Chance]

Originally Posted by nwood488

We have a Majestic 23A and parked on some family land with full hook ups. We are experiencing 90-98 heat right now in Kentucky. We have very little shade unfortunately. The past few days the A/C won’t get much below 77, even on high. It wasn’t like this when we first got here and experiencing similar heat around 90. We would come in at night and it would be 74 and sometimes slightly cooler.

Does this sound normal?

For me 77 F inside when it’s that hot outside would be OK. For what it’s worth, Coleman and other RV companies rate their air conditioner capacity with 80 F inside and 95 F outside (so based on that 77 F is a success). At those temperatures is when A/C provides 13,500 or 15,000 BTU/hr of cooling or whatever the rating is.

Controlling humidity is very important also because it places extra load on air conditioner, plus it makes you feel warmer. Try not to leave doors open too long, or take long showers in middle of day when A/C has to work hardest. Anything that generates a lot of heat inside like cooking, running microwave, etc. won’t help you stay cool either.

[16ACE27]

Originally Posted by nwood488

We have a Majestic 23A and parked on some family land with full hook ups. We are experiencing 90-98 heat right now in Kentucky. We have very little shade unfortunately. The past few days the A/C won’t get much below 77, even on high. It wasn’t like this when we first got here and experiencing similar heat around 90. We would come in at night and it would be 74 and sometimes slightly cooler.

Does this sound normal?

For a single 13.5K unit, or even a 15K unit - yes.

[Judge]

Originally Posted by JimOIB

To add to Judge’s comments related to heat gain, put pillows in the vent openings in the roof since they directly bring heat into the coach. Also, if you have a slide then close the gaps between the slide floor and the coach floor. This 1 to 1-1/2 strip can cause the A/C to draw warm air in from the outside. Go to your fav HW store and get some foam pipe insulation the size of the gap and stuff it in.

One simple overlooked item is cleaning your A/C filters - with heavy use the filters get dirty fairly quick. It will make a big difference on airflow.

Execellent point on the vent pillows! I use the Camco ones as well and forgot to mention those. [emoji106]

[Jimbo56]

Originally Posted by Chance

For me 77 F inside when it’s that hot outside would be OK. For what it’s worth, Coleman and other RV companies rate their air conditioner capacity with 80 F inside and 95 F outside (so based on that 77 F is a success). At those temperatures is when A/C provides 13,500 or 15,000 BTU/hr of cooling or whatever the rating is.

Controlling humidity is very important also because it places extra load on air conditioner, plus it makes you feel warmer. Try not to leave doors open too long, or take long showers in middle of day when A/C has to work hardest. Anything that generates a lot of heat inside like cooking, running microwave, etc. won’t help you stay cool either.

Yes to above. A tech once told me that in the high heat/humidity southeast, every time you open the door, it’s like dumping a bucket of water in.

[The Gritz Carlton]

So funny...all great advice but it looks like you're invaded with and fighting hornets while doing all this. Wouldn't it be really cool (no pun intended) if they just learned from their past and build them right to begin with?

[bevedfelker]

A 13,500 BTU A/C is really going to struggle in those temperatures. When we bought out Vegas 24.1 new in 2015 we have the optional 15,000 BTU A/C. The first 5 years we owned it we lived in FL. We've been camping in high 90s and low 3 digit temps in FL. My wife managed to keep our RV sitting in the sun, all the winds covered, at almost meat locker temps.

From my experience I can say there is a huge difference in an RV A/C at 15,000 BTU verses a 13,500 BTU one. Having an RV that is only 25' long also helps. I'm sure that 15,000 would struggle in an Rv of 30' plus.

[The Gritz Carlton]

My brother is looking at an entry level (probably minimal insulation) TT right now. 21' with one 11K A/C mounted more to one end. I told him to have it upgraded to a 13.5K or preferably a 15K and how much worth it the investment would be. He said..."They do this for a living...they know what it takes". He said the sales-goober told him, the 11K units cool better than the bigger ones as a result of the advanced filtration systems in the small units. You can lead a horse to water...hold its head under...but you can't make it drink. Everyone has to learn so much on their own.

[Connieb]

Originally Posted by nwood488

We have a Majestic 23A and parked on some family land with full hook ups. We are experiencing 90-98 heat right now in Kentucky. We have very little shade unfortunately. The past few days the A/C won’t get much below 77, even on high. It wasn’t like this when we first got here and experiencing similar heat around 90. We would come in at night and it would be 74 and sometimes slightly cooler.

Does this sound normal?

It sounds normal to me,with one ac,all blinds closed and a fan on,I think that is pretty good

[CTRvs666]

Originally Posted by Judge

You also need to do more than just run the A/C..... once you verify the temperature differential between air entering the A/C and the air exiting the A/C has a difference of 16 - 22 degrees. A digital thermometer works great because you can stick the probe into the intake and exhaust vents in the A/C unit.

- Purchase the WeatherTech Full Cab Sun Shade Kit and install it every time you stop to keep the sun and heat out of the cab by covering the windshield and door windows. If you don't give those windows it will be a losing battle.

- Close all window shades.

- Pull the curtain over the cab-over bunk. If you don't have a curtain, make one. There is no insulation in the front cap and it can generate a lot of heat that makes its way into the living areas.

- Don't wait for it to get hot to do all of the above and run the A/C. The sooner you start the better chance you have for beating the heat.

- Then if you want to get "fancy" you can climb on the roof and insulate the evaporator enclosure and a few other tricks you can read about on the forum.

I see this post every year, and I have to suffer with it in the summer in the desert. I hang a large thick quilt over the bunk to block the cab heat, use the soft pillows to block the vents, and close the slides if we leave the coach, and it is still 20 degrees at best. So it averages about 105 for 3 months, and that means 85 in the coach.

But after the sun goes down, the difference is a good 30 degrees without the sun on the exterior. So we can get it to cool off decently for sleeping.

[Scubawise]

Originally Posted by Chance

For me 77 F inside when it’s that hot outside would be OK. For what it’s worth, Coleman and other RV companies rate their air conditioner capacity with 80 F inside and 95 F outside (so based on that 77 F is a success). At those temperatures is when A/C provides 13,500 or 15,000 BTU/hr of cooling or whatever the rating is.

Controlling humidity is very important also because it places extra load on air conditioner, plus it makes you feel warmer. Try not to leave doors open too long, or take long showers in middle of day when A/C has to work hardest. Anything that generates a lot of heat inside like cooking, running microwave, etc. won’t help you stay cool either.

Great poins learned the hard way.
Used to cook and use microwave in these temps.
It Does NOT work !

[Judge]

Originally Posted by CTRvs666

I see this post every year, and I have to suffer with it in the summer in the desert. I hang a large thick quilt over the bunk to block the cab heat, use the soft pillows to block the vents, and close the slides if we leave the coach, and it is still 20 degrees at best. So it averages about 105 for 3 months, and that means 85 in the coach.

But after the sun goes down, the difference is a good 30 degrees without the sun on the exterior. So we can get it to cool off decently for sleeping.

Not sure how you camp in that kind of heat. We live in Florida and we won't camp down here when temps are in the mid-90's every day with intense sun and high humidity and only cool down to the 70's or 80's at night. I don't even keep the coach down here so the heat doesn't tear it up. We spend most of the hot months in PA visiting family and have a garage there I store it during the winter months. We do a 2 - 3 months trip starting in late August and a couple short trips in the north before then.

The hottest temps we have camped in was the low to mid 90's in Nashville last August but I could get the coach down to the low 70's during the day and upper 60's at night. We also boondocked at my inlaws for the 4th and temps were low 90's but the coach was low 70's during the day.

I'm sure if it was 100+ out with intense sun upper 70's to low 80's would be the best to hope for in those conditions. Camping in that weather is jut not fun from my perspective. Give me the spring or the fall.

[Chance]

Southeast Texas has been unusually warm this year, and much warmer than what I experienced regularly in south Florida over last 10 years.

Houston has seen many days already at 100 F or higher (actual temp with feel-like temps around 10 F higher), and worse yet just an hour’s drive north of us temperatures have hit close to 110 F range, with feel-like much higher than that. Closer to Gulf Coast is more humid but typically cooler. Florida is kind of same way — ocean breeze helps a lot.

We don’t normally camp just to stay in RV, so if it’s too hot to be out doing something fun we are likely not out camping at all. As travelers (touring) many hot days are spent driving during warmest part of day, and fortunately OEM chassis air conditioners work pretty good in Ford van chassis.

Anyway, when it’s 100 to 110 F in the shade and humid, I doubt many RVs will stay much below 80 F. I haven’t owned or rented one that could; though I know a few with oversized A/C capacity can. I think they are rare because 99+% of time that much cooling isn’t needed, or owners will be staying home anyway if it’s that hot. I expect full timers are a different story.

[rvclassrooms]

remove the ac cover on the inside of the coach, look at how "insulation" separating the intake and the out flow. Chances are the thing has fallen down and you are just pushing out warm air.
I took mine apart used silver duct tape to hold the insulation in place, then I added Dyno lining so it was more insulated. I also sealed off the big out flow so all the air went through the vents and not out the ac unit itself. This made it way cooler and also significantly more quiet.
I also dyne lined my flooring and along the firewall on the inside. I added more dyne liner under the dash and heavily insulated the dog house cover. I also carpeted the doghouse cover. Doing the dyne liner not only made to cooler but my cabin decibels went from 75-80 to 50. I can. have a normal conversation with out screaming.

Anyway there's many videos showing how t correct your roof top ac. Good luck!

[Beau388]

San Antonio set the all time heat record for a single month. July had 29 days with high temperature of 100 or better. Dew points are in the low 70's.

We took the RV out for its monthly drive last Friday nigh. We made the 50 mile trip west to Hondo for TexMex at Azteca. The dash and Mach15 ACs kept the coach cool with the outside temp of 101 at 5 pm. Never turned the rear Mach 8 heat pump on.

[Jimbo56]

Originally Posted by rvclassrooms

remove the ac cover on the inside of the coach, look at how "insulation" separating the intake and the out flow. Chances are the thing has fallen down and you are just pushing out warm air.
I took mine apart used silver duct tape to hold the insulation in place, then I added Dyno lining so it was more insulated. I also sealed off the big out flow so all the air went through the vents and not out the ac unit itself. This made it way cooler and also significantly more quiet.
I also dyne lined my flooring and along the firewall on the inside. I added more dyne liner under the dash and heavily insulated the dog house cover. I also carpeted the doghouse cover. Doing the dyne liner not only made to cooler but my cabin decibels went from 75-80 to 50. I can. have a normal conversation with out screaming.

Anyway there's many videos showing how t correct your roof top ac. Good luck!

So you stuck Dynamat up inside from the wheel wells?