A/C upgrade? 2017 C class Grayhawk

[Ronp20m]

I was on here last year and several people said about 20 degrees differential is all you can expect. So how do you ever go camping in the southwest? I was out this week in OK and my phone said 93 and inside was 89. Granted 93 was official temp and I'm positive it was much higher on concrete pad with minimal shade, over 100 no doubt since I was out there setting up. The only way I've been able to bring temp down was to turn on car AC for 1/2 an hour or so.
I'm closing all windows, bought fans to circulate air, wife wouldn't let me bring in slides.
Surely there are AC upgrades and at this point I'm will to pay handsomely for some cool air.
Have had unit serviced, cleaned all filters etc.

Bought it used so also wondering about a coat of reflective paint on roof as well. like a boat getting a fresh bottom coat every few years.

Need help

[RetiredOne]

You might want to drop down the inside plastic cover to the A/C and check the divider between intake and exit. Some people have reported that the divider was in the wrong place, which doesn't separate the air flow, and allow it to pass through the A/C itself.

Another thing to check, if you can get your hands on a temp gauge, is what the temps are going in and out, to see if your A/C is actually chilling the air or maybe needs a recharge.

[JimD]

Disclaimer - I am not an air conditioning expert.

I believe that ac units need to be properly sized for the area they need to cool. For home units there are all kinds of formulas and charts that take into account geographical area, room size, windows, insulation, etc. Then given all that a contractor will install a unit that should be able to keep up with the demand.

But, that has never seemed to work out for me. I have never had an ac that would properly cool my house. I believe contractors will just go with the smallest option they can get away with. Just my opinion.

Now in an RV you don't have a heck of a lot of options. I think the popular sizes of available units are 11000, 13500, and 15000 btu. The bigger the unit, the better it will be at cooling. With the poor insulation in these rigs I think you need the biggest unit you can get by with or multiple units.

BUT....These things pull major power and we are limited to 30 amp or 50 amp service. You can only stuff so much cooling into these rolling hot boxes. I have 2 11000 units in my 32 foot Greyhawk and need to run both to get decent cooling on hot days. With both going I can easily get my 20 degree drop and better at times if the humidity is not killer.

My son has a big 5th wheel that came with a single 15000 btu unit that is basically useless for that giant volume of hot air. He recently added a second 13500 unit in the bedroom and partially ducted it into the main area. He said it has helped quite a bit.

My other son has a new 5th wheel that has 2 units but the bedroom one is not ducted into the main area so it is basically useless. I told him to put a tower fan at the bedroom door to pull cold air out of the bedroom and force it down to the main area. That has helped.

So what do you do. Definitely have a good fan to move the air around. You will feel cooler for the same air temp if the air is moving. If you can add a second air, do it. That would be the best thing you could do. If you manage your high power needs properly you can run 2 11000 units on a 30 amp service. If you have 50 amp you can go bigger with each.

It is my opinion that a single AC in a big RV will just never be enough if you are in a hot/humid area.

[CAG]

My answer is simply we do not camp in the desert in the summer. That is why the roads going out of Phoenix and Tucson are clogged with RV's going to the mountains on Friday afternoon.

I had a 37 ft toy hauler with one AC unit that would, if you got a jump on the heat in the morning, hold 80-85 with it being 105/110 outside. Two units might have made a difference but I just never camped in hot weather so did not add one. I did use one of the portable "on wheels" units once and the two units would freeze you out but again I did not need both or even the one when it is 75 at higher altitude.

The Greyhawk has one AC but the only place I might use it will be in SE Arizona in late summer where the altitudes are 5K feet and day times get into the high 80's. So, if you are planning to camp in hot weather you will need more than the one AC and this especially is true when we hit Monsoons and the nighttime temps stay in the high 80s.

Also the reason that I say Sat dishes on the roof do not work well in this country because we park under trees a lot.

[Trapper2020]

Living in Houston made us only consider units with 2 ac’s on them settled on Jayco 29mv for this reason. When stopping in hot area pre cool rig last hour of drive using generator. Also when stopping for day as soon as you are leveled open engine hood to let hot air out the front. This will allow heat out instead of holding it in to escape under rig. Helps a lot. We also put aluminum bubble wrap in over head shower dome. Good luck

Enjoy the journey

[Ronp20m]

Thanks for input, got a lot to learn

[Florida Ranger]

My 2018 Greyhawk 31fs has 2 11000 btu ac’s and works good here in Florida. But it helps to run 1 of the ac units while traveling to keep the rear of motorhome good and cool. This will help when you get campground and set up, takes shorter time to cool down totally inside. I like to keep temp at 75 to 77 when we are camping. Last Greyhawk only had 1 ac at 15000 btu and it was a hard to keep my inside cool enough to be comfortable...My 2018 has all tinted windows and it really helps...

[t18skyguy]

A lot of RV's get traded in because they only have one AC unit. It's a common mistake. The dealers lot is usually stocked with all kinds of rigs with only one AC. They can buy them a bit cheaper but the buyer finds out later it's inadequate. The industry standard is anything 27 foot or longer needs two AC units. There are countless threads across many RV forums on this issue. Bringing in the slides would have helped, Less area to cool. Another option if possible, park the rig in a site with shade or orient it so the sun hits the back of the coach and not the front or sides where all the windows are. I'm not sure which rig you have, but sometimes there is a red wire that runs through the ceiling to the back vent if you want to put in another AC. I've seen it in the 2017 Jayco electrical schematics.

[Jopopsy]

I’ve made one AC unit work in my 32’ Class C’s. Once it starts to get really hot I’ll partition off the back bedroom area, open the dump vents on the Coleman, and perhaps even pull in the main slide if I REALLY had to (but so far I have not). I have heat shields on the windshields in the cab, and I keep the cab curtain up. I put vent pillows in the overhead vents, and I have some styrofoam insulation board plugging the skylight. My rig is white, which I prefer as while the paint is pretty it soaks up the heat and transfers it back into the coach. My vent covers are all white, and I even took the AC cowl off my roof and spray painted it white (Krylon). I turn the AC on as soon as the inside of the rig hits 73 degrees or so, and I keep the T-stat at 74. If you have a analog T-stat, switch it out ASAP for a digital one. Make sure your overhead vents aren’t blowing on the T-stat as well.

I have also inspected the inside of my AC unit and taped everything up inside there so that the air did not squirt out where it wasn’t supposed to.

I would have loved the dual AC units on my rig - but I couldn’t find a left over (good deal) and I was also hesitant for the additional 100 pounds of weight penalty hanging off the rear axle. Long Greyhawks are notoriously porky.

Maybe one day I’ll have a Class A w/ gobs of CCC (thats actually useable) and I’ll spin up my dual AC units - but until that day comes this is how I roll.

[EA37TS]

Originally Posted by t18skyguy

A lot of RV's get traded in because they only have one AC unit. It's a common mistake. The dealers lot is usually stocked with all kinds of rigs with only one AC. They can buy them a bit cheaper but the buyer finds out later it's inadequate. The industry standard is anything 27 foot or longer needs two AC units. There are countless threads across many RV forums on this issue. Bringing in the slides would have helped, Less area to cool. Another option if possible, park the rig in a site with shade or orient it so the sun hits the back of the coach and not the front or sides where all the windows are. I'm not sure which rig you have, but sometimes there is a red wire that runs through the ceiling to the back vent if you want to put in another AC. I've seen it in the 2017 Jayco electrical schematics.

Not sure what industry standard you are referring to but there are quite a few motorhomes and trailers in the 30 foot range that come with one AC unit (sometimes 13. K other times 15K). Some of these will have an option to add 2 13.5 in lieu of a 15.

Can you tell us which industry standard states anything over 27 feet or longer needs 2 AC units. Inquiring minds would like to know.

[Jagiven]

OP, the 20 temp drop, is the temperature the air that is crossing the coils can drop, in the short amount of time it is in contact with the coil. Recirculate, and repeat over and over, and you can get much cooler temperatures. Until the thermostat is satisfied or the external heat load and ac's capacity match.

[RetiredOne]

Originally Posted by Florida Ranger

My 2018 Greyhawk 31fs has 2 11000 btu ac’s and works good here in Florida. But it helps to run 1 of the ac units while traveling to keep the rear of motorhome good and cool. This will help when you get campground and set up, takes shorter time to cool down totally inside.

Along those lines, what if the people with one A/C used their cab A/C system for short term supplementing the roof A/C during hot periods? I know it's a short term fix, but cranking the cab A/C on maximum for a short period of time would help cool down the rig for a while.

[t18skyguy]

Originally Posted by EA37TS

Not sure what industry standard you are referring to but there are quite a few motorhomes and trailers in the 30 foot range that come with one AC unit (sometimes 13. K other times 15K). Some of these will have an option to add 2 13.5 in lieu of a 15.

Can you tell us which industry standard states anything over 27 feet or longer needs 2 AC units. Inquiring minds would like to know.

Over on RV.net, there is a lifelong RV tech named Doug. He is very well respected and helpful with so many issues that the average owner would never be able to troubleshoot. I got that spec from him. The industry does have standards; their just widely ignored to save money. To me, it makes perfect sense. I had a 22 footer with one AC and it was fine. It would not be OK in my 31FS. I'll ask Doug where these standards are written, maybe he can direct me, but I trust him.

[EA37TS]

Originally Posted by t18skyguy

Over on RV.net, there is a lifelong RV tech named Doug. He is very well respected and helpful with so many issues that the average owner would never be able to troubleshoot. I got that spec from him. The industry does have standards; their just widely ignored to save money. To me, it makes perfect sense. I had a 22 footer with one AC and it was fine. It would not be OK in my 31FS. I'll ask Doug where these standards are written, maybe he can direct me, but I trust him.

RVIA at the time is the industry standard and there is no published and accepted standard for the sizing of AC units in RVs. RV.net is owned and operated by Camping World whose reputation for things related to the maintenance and repair of RVs is less that stellar.

If it is not written and accepted by the industry it is not a standard and is only one's personal opinion.

The industry is not ignoring a standard to save money because there is no published standard to ignore.

[Route 66 Traveler]

Read through this Thread, which is a “Sticky” in the Chat topic. I made the suggested repairs and it made a world of difference in my AC. I live in AZ and now camp comfortably in the summer. Also check your ducts for leaks that blow cold air into the space between your ceiling and roof.

https://www.jaycoowners.com/forums/f...ing-67173.html

https://m.youtube.com/watch?v=rxCljB...ature=youtu.be

[Jopopsy]

Originally Posted by Route 66 Traveler

Read through this Thread, which is a “Sticky” in the Chat topic. I made the suggested repairs and it made a world of difference in my AC. I live in AZ and now camp comfortably in the summer. Also check your ducts for leaks the blow cold air into the space between your ceiling and roof.

https://www.jaycoowners.com/forums/f...ing-67173.html

Yep, this is what I did to my AC unit. Great video - thanks for posting it.

[t18skyguy]

Originally Posted by EA37TS

RVIA at the time is the industry standard and there is no published and accepted standard for the sizing of AC units in RVs. RV.net is owned and operated by Camping World whose reputation for things related to the maintenance and repair of RVs is less that stellar.

If it is not written and accepted by the industry it is not a standard and is only one's personal opinion.

The industry is not ignoring a standard to save money because there is no published standard to ignore.

RV.net may be owned by camping world, but the people who participate in the site are not. There are some top RV pro's in there with 30-40 years experience. I'm going to ask Doug where he got that figure, but in lieu of that, just search this forum, RV.net, IRV2, and read the literally hundreds of posts from folks that made the mistake of buying a big rig without 2 AC's. It's all there in black and white. As far as there being no standard, that may turn out to be just your opinion.

[t18skyguy]

Originally Posted by EA37TS

RVIA at the time is the industry standard and there is no published and accepted standard for the sizing of AC units in RVs. RV.net is owned and operated by Camping World whose reputation for things related to the maintenance and repair of RVs is less that stellar.

If it is not written and accepted by the industry it is not a standard and is only one's personal opinion.

The industry is not ignoring a standard to save money because there is no published standard to ignore.

I did contact Doug Grainer, and you are correct. He meant it was a standard for his dealership. Here it is in his words.

There is NO standard on how many AC units need to be installed. You can have NO AC units. You can have up to 4 or 5 on 50 amp service. I state a 27 foot and MORE length as required to keep the RV cool enough in higher than 85 degree temps. I state this from EXPERIANCE in DFW Texas temps over 41 years as a DFW RV tech. As a Dealership we stopped having 1 AC on 27 or longer CLASS A's back in 1982. Back then you had only 30 amp service so you had to run the Genset for the Rear AC. We got tired of the customers complaints that they could not keep cool in hot temps. This was back when they had NO DUCTWORK in the ceiling. Then once they started Ductwork, they installed slides which made MORE cooling space in a standard unit. So, I laugh when I see bozo's state that they can cool a 27-32 foot unit(especially with 1 to 2 slides) on 1 AC unit. NOT IN TEXAS. NOWHERE where the ambient temps are over 80 to 85 degrees. Doug

[Jaycomelbourneng]

I have done the tips in the video on sealing a/c with foil tape. We also have a slide topper(which helped). One of the largest things was the silver foil for the cab windows and windshield. We also cut foil to fit all windows and use the vent "pillows". It allows us to camp in the summer.