2nd AC Unit in Eagle HT 28.5RSTS

[Husky]

New 5ver owner here. Bought new last October. When we bought it, it only had the rear AC unit in it. You know where I'm going with this. This is our first summer with the new rig and that one rear unit is not cooling the 5ver in this hot Georgia heat wave we have now. I am going to have a new AC unit (same as the rear, AIREXCEL Coleman Mach 15) installed up front over the bedroom and ducted into the existing duct system, so we can enjoy camping in the summer also. My question is with the best way to control this new AC unit. Is it best to have it wired into the existing thermostat and let that one thermostat run both AC units? Or is it better to have a second thermostat installed in the bedroom to control that forward unit separately? And speaking of thermostats, the original Coleman analog that came with the 5ver seems questionable as to how well it controls the cooling and heating. Looking at converting over to digital thermostat(s). I would appreciate input from those who have experience in this area. Thank you for allowing me to benefit from your knowledge and experience.

[2nOZ]

We have the 2018 28.5 RSTS. Ours came with both ACs. I’m assuming you have 50 amp and provisions for the optional unit. We have two separate controls. The one in the hallway controls the AC and heat for the main unit and the one in the bedroom controls the bedroom. We run both units at the same time to cool the camper down quickly when it’s hot. I swapped out the analog thermostats to the Coleman digital ones and they are far more accurate.

[Cincinnati Kid]

Well we have a new 28.5 RSTS with one A/C too, so I'll be watching this post. You might want a low profile for your second ac, it's higher on the roof than the first, and some people here have been having height problems.
Also, I wondered how the thermostats and ducting would work together, so I'll stay tuned. Thanks.

[vegasguy]

Originally Posted by 2nOZ

We have the 2018 28.5 RSTS. Ours came with both ACs. I’m assuming you have 50 amp and provisions for the optional unit. We have two separate controls. The one in the hallway controls the AC and heat for the main unit and the one in the bedroom controls the bedroom. We run both units at the same time to cool the camper down quickly when it’s hot. I swapped out the analog thermostats to the Coleman digital ones and they are far more accurate.

Different trailer but similar. Exactly the same as stated above. Think I read before the wire for the thermostat is already in the wall, right above the switch for the bedroom lights. I knew I needed two A/C's so that is how I ordered it, but I also switched out the factory crappy thermostats for Coleman digital. Some people use certain home style thermostats that are battery powered.

[vegasguy]

If you don't have 50amp you are mostly out of luck. There are some ways around it if you look online, but more work, and you probably wont get a licensed business to do it.

[Dargo]

My new 5ver has 2 A/Cs and 2 different thermostats. Electronic both.

My old RV had a mechanical one and these are much better. Upgrade for sure.

[Chrisb-24]

I have the same unit, 2016 with two A/C's. I read an article and any RV over 30' needs two A/C units. People really need to do there home work before buying. These Damn salesmen are only out for there commission. Anyways you need two thermostats, one to control the main cabin and one for your bedroom. This is how my 5ther is wired. When we go to S. Texas most of the time I run just the main cabin for cooling. It's ducked into the bedroom as well. When I turn the bedroom A/C on sometimes it's only on fan.

[Mopar_Earl]

If prep for second unit, thermostat wiring will be there. Normally in the wall near the light switch. You want two stats.


Earl

[blujay40]

Originally Posted by Cincinnati Kid

Also, I wondered how the thermostats and ducting would work together, so I'll stay tuned. Thanks.

Works pretty well actually.

We have found that in our Eagle TT, if we keep the BR AC set about 5 degrees lower than the LR, the BR unit runs more during the day and the LR unit runs more at night, minimizing the noise in areas where we are at a given time.

We hardly ever need to touch them anymore.

[RipinSC]

You want a thermostat in the bedroom for the front air.

[Husky]

Thanks for the input. Ours is wired for 50 amps. your input is exactly what I was looking for. Thank you.

[DNelson]

Our 2018 28.5 RSTS was ordered with one AC but wiring for the 2nd. It was soon obvious that 2 ACs were needed so I ordered a Coleman Mach 8 15K BTU low profile unit from Dyer RV for less than a $1,000 with free shipping. They are easy to put in, the hardest part is getting the unit on top of the RV. You will want a separate thermostat in the bedroom. The thermostat wiring for ours was accessible by removing the light switch. I mounted a digital house thermostat with batteries just above the light switch. I had nothing but problems with a digital Coleman thermostat on the other AC so changed that to a digital house thermostat with batteries also.


Dwayne

[Cincinnati Kid]

So we have the same setup, a 2019 28.5 RSTS with 50 amp/ 2nd ac prep. I'll probably start crying like a baby the first time we camp in the south with one AC.
I'm assuming the bedroom unit ties into the existing ceiling ductwork.

Question- If they share the ductwork does that confuse the thermostats? If it gets cool enough in the living room, and that unit shuts off, but the bedroom is still hot, does the bedroom unit freeze out the living room?

[DNelson]

The duct work is shared. The beauty of this setup is that you can use the bedroom AC to cool the living area and vice versa. That way the noise in the room being cooled is much less. We control balance when using one AC with the vents. During the day we run the bedroom AC with those vents closed and set the temperature of that thermostat to vary the living area temperature. When it is really hot we run both ACs and still close the bedroom vents so that all the cool air goes to the living area.


It is really easy to keep temps where you want them. In fact when it is REALLY hot and humid we sometimes wish we had a 3rd AC!

[Mopar_Earl]

Originally Posted by Cincinnati Kid

So we have the same setup, a 2019 28.5 RSTS with 50 amp/ 2nd ac prep. I'll probably start crying like a baby the first time we camp in the south with one AC.
I'm assuming the bedroom unit ties into the existing ceiling ductwork.

Question- If they share the ductwork does that confuse the thermostats? If it gets cool enough in the living room, and that unit shuts off, but the bedroom is still hot, does the bedroom unit freeze out the living room?

The shared duct system works beautifully.


Earl

[wwpayne]

I recently installed a 13,500 low profile unit up front in my fifth wheel. Tested in out this weekend. My thoughts are you will want to control the bedroom unit with it's own thermostat. The bedroom cools fairly quickly as compared to the rest of the unit and at night I wouldn't want the bedroom unit coming on. too noisy

[GraftonGuns]

Husky, I have a 2017 Eagle HT 27.5 and had the same issue. I purchased a 2nd Coleman Mach15 a month ago. I did the install myself. Do not hook both together on one Thermostat. Put in a separate T-stat for the bedroom otherwise, you'll need a 50amp receptacle to run them at every campground you go to. Trust me! I also purchased the Chill grille for my bedroom setup . $100 but well worth it. This way you can divert the AC to the ducted system. Or, better yet, Direct it to the bedroom exclusively. I purchased a 2nd Analog cool only T-stat from a local RV store. Now, I can run each unit independent. You can run both units on "Fan Only" with the 30 amp hookup. I used mine this past weekend and it worked flawlessly.

[Husky]

Grafton Guns, thanks for the reply, exactly what I needed. I was thinking about the Mach 15, but I am concerned about clearance. So I am checking out the Mach 10 for an extra 3" clearance. Has clearance been an issue for you anywhere with the Mach 15? I am looking at the Chillgrille also. I see two different ones. I am thinking I need the Lateral Ducted Chillgrille and not the Straight Thru Ducted Chillgrille. Am I correct on that? I am thinking about the second thermostat being a digital one. Any thoughts on that. I appreciate your input as I nearing pulling the trigger on this purchase. Thanks

[Mopar_Earl]

Originally Posted by Husky

Grafton Guns, thanks for the reply, exactly what I needed. I was thinking about the Mach 15, but I am concerned about clearance. So I am checking out the Mach 10 for an extra 3" clearance. Has clearance been an issue for you anywhere with the Mach 15? I am looking at the Chillgrille also. I see two different ones. I am thinking I need the Lateral Ducted Chillgrille and not the Straight Thru Ducted Chillgrille. Am I correct on that? I am thinking about the second thermostat being a digital one. Any thoughts on that. I appreciate your input as I nearing pulling the trigger on this purchase. Thanks

Go mach 8. Half the height of the mach 15. Both 15k btu. Mach 8 looks better too.


Earl

[Husky]

Originally Posted by GraftonGuns

Husky, I have a 2017 Eagle HT 27.5 and had the same issue. I purchased a 2nd Coleman Mach15 a month ago. I did the install myself. Do not hook both together on one Thermostat. Put in a separate T-stat for the bedroom otherwise, you'll need a 50amp receptacle to run them at every campground you go to. Trust me! I also purchased the Chill grille for my bedroom setup . $100 but well worth it. This way you can divert the AC to the ducted system. Or, better yet, Direct it to the bedroom exclusively. I purchased a 2nd Analog cool only T-stat from a local RV store. Now, I can run each unit independent. You can run both units on "Fan Only" with the 30 amp hookup. I used mine this past weekend and it worked flawlessly.

Grafton Guns, thanks for the reply. Exactly what I needed. I am thinking about the Mach 15. Have you had any problems with clearance. Looking at the Mach 10 also. I am looking at the Chillgrille also. Do I need the Straight Thru Ducted Chillgrille #8430A6301 or the Lateral Ducted Chillgrille #8430A6321? Also, looking at a digital thermostat, Heat/Cool # 9430-3382. Got all these numbers off of Airexcel's website. Thanks for you input. I appreciate it.