Replacing Roof Top A/C units

[subtroll]

We're doing a major renovation of our 10 year old National MH this year, (roof work, slide seals and paint) and I'm thinking about replacing both Duo-Therm A/C units only because they are 10 years old. Both still work fine but as any electro-mechanical devices exposed to the elements, they have a limited lifetime and repairs/replacements on the road are generally more expensive.

I may even replace one 10k BTU unit with a larger (15K BTU) one.

Are there better units available?...better brands, newer technology?

I'd like to be able to use the same controller which also controls the furnaces etc.

[TechWriter]

sofar-sogood wrote:
We just had a 10 year old unit fail in 100+ temps in Utah. With both units working we were barely OK. Ended up having to go 145 miles out of our way to get BOTH units replaced and lost a few days in the process. Just sayin...

Exactly -- ACs don't fail in Winter.

I replaced both my 11-year-old, original 13.5k Dometic Penguins with Penguin IIs and the new new Comfort Control Center (CCC) II thermostats.

Couldn't be happier. One of the best upgrades I did.

I decided it was best to replace them when I had total control over who did the work instead of relying on some repair shop on the road.

[deandec]

18 year old Dometics with heat pumps. Still ticking........

[sofar-sogood]

We just had a 10 year old unit fail in 100+ temps in Utah. With both units working we were barely OK. Ended up having to go 145 miles out of our way to get BOTH units replaced and lost a few days in the process. Just sayin...

[f_wernlein]

A few years ago I replaced on of the OEM Coleman AC units on our coach. It was 15 years old. We hit a national chain RV store the next day...and for a standard price for the unit and a reasonable installation fee were on our way in 3 hours.

The other one's still fine...and if/when it fails...I'll replace it then.

[dougrainer]

MountainAir05 wrote:

dougrainer wrote:

MountainAir05 wrote:
The newer unit will not work with your older thermostat.

National used Dometic Brisk Air models and the control system will work with a new Brisk air but not a Penguin model. Doug

Thanks, was mis inform when I call about replacing mine

There is a LOT of confusion with matching OLD control systems with NEW Dometic AC/HP units. Doug

[conmoto]

The new AC that I replaced my failed bedroom unit with is MUCH louder than the original. I will stay with the living room unit until I MUST replace it. Just my 2 cts

[MountainAir05]

dougrainer wrote:

MountainAir05 wrote:
The newer unit will not work with your older thermostat.

National used Dometic Brisk Air models and the control system will work with a new Brisk air but not a Penguin model. Doug

Thanks, was mis inform when I call about replacing mine

[ScottG]

Dutch_12078 wrote:
I have two 18 year old Duo-Therm 13.5K Btu A/C's on my coach roof. Both work fine. If one fails, I'll replace it, but not "Just in case..."

I think your better off. The old ones seem to work better, or at least mine did on my old TT.

[Dutch_12078]

I have two 18 year old Duo-Therm 13.5K Btu A/C's on my coach roof. Both work fine. If one fails, I'll replace it, but not "Just in case..."

[dougrainer]

MountainAir05 wrote:
The newer unit will not work with your older thermostat.

National used Dometic Brisk Air models and the control system will work with a new Brisk air but not a Penguin model. Doug

[wa8yxm]

I can not comment on DuoTherm but I will comment on a replacement I did last summer... One of my Carrier Air V's died due to bad workmanship, alas, 7 years old so no warranty even under Uniform Commercial Code.

Back to topic.

I replaced a 13,500 BTU Carrier with a 15,000 BTU Advent, This is a direct replacement for the rooftop unit and did not require replacing the rest of the unit, it still uses the same controls. One slight mod (included with the kit) took about 2 minutes to complete.

The Original 2005 Carrier Air V drew 13.5 Amps running

The new, 11% more cool Advent draws ..... 13.5 amps running

11% more cool, same energy use..

So I support your plan to upgrade.

HOWEVER.. I'd not do it till it's needed.

[MountainAir05]

The newer unit will not work with your older thermostat.

[Dale_Traveling]

If they are working efficiently I would leave them be. When the day comes when one fails the hardest part of the replacement if getting the new on the roof and the old one down. Going with higher BTU units is difficult to judge. If you have too much cooling capacity you will lose the dehumidifying effect and the coach will feel like a cave. Cold and damp. If you do replace them consider going with heat pumps if your camping habits will support the use and additional cost. Spring and fall are my favorite camping times but keeping a supply of propane for heat is something I would like to do without.

The original thermostat should work. More or less it's no more than a dry contact relay that will command the unit to turn on and off. If you do replacement just to be sure contact the manufacture.

As part of the refurb project I would consider looking to see if you can add drain lines somehow rather than the condensate draining on the roof.

[JackMS]

Seems the new units are using r410. They also claim to be more efficient, but based on the spec sheets, don't see a lot of difference. I just ordered a brisk air 2 with 410 in it to install as a third unit. Some places I go the 2 won't keep the temp where I want it. To me if you spend time in hot areas you can't have enough a/c. So I would buy the biggest units you can afford.
Wherever you buy the units from should be able to tell you if it will work with your controller.

[The_Texan]

I am not a member of the throw away generation, and this is one prime example why. Those AC units will, in all probability last another 10 years and provide good service. Why would anyone toss $2000 in the trash, just because they "might" break somewhere down the road? Sorry, but I can NOT agree with your reasoning. I have been RVing since 1974 and have not seen to many AC units go south at 10 years of age.....