Community Forums

kmburns49 · 02-01-2016, 10:14 AM

Will a 15k BTU A/C (ducted to front and rear) be adequate for a 33' coach (with a 4k genset)?
Adding a second 13.5k BTU unit in rear requires upgrade to 50amp service and a 5.5k genset. Weight could be a factor.

Mich F · 02-01-2016, 11:17 AM

Quote:

Originally Posted by kmburns49

Will a 15k BTU A/C (ducted to front and rear) be adequate for a 33' coach (with a 4k genset)?

Maybe it will, maybe it won't. My bottom of the line Itasca class C 31K, is 32 1/2' long. It has a single 15,000 BTU ducted A/C which has been more than adequate each time I've used it, totally within Florida, throughout the year.
Others will join in to say you must have 2 A/Cs.

dwhit · 02-01-2016, 11:32 AM

Our last Class A was a 1999 34 foot Damon DayBreak with one "super slide". It had a ducted 15K Coleman MachIII. It cooled adequately...but then we didn't camp in Death Valley. If started in the morning hours it would stay comfy throughout a 95 degree day. Camping in the shade is always very important.

There are some that insist on 70 degrees on a 95 degree day with full sun exposure. It may take three a/c units to do that. Yet with major humidity removed 78 degrees feels cool.

I really liked the unit and I'd but it again...'cept we went to a TH that has 2 a/c's...yet the second a/c in the bedroom is barely usable. Sounds like a 120 inch S&S mtcyl engine idling 24 inches above our heads. Sleep is impossible. We don't use it.

drewtk · 02-01-2016, 12:06 PM

If it's over 90 degrees, then I don't think it'll be enough with that size RV. That single A/C might bring it down to an adequate level if you can tolerate a little higher temperature, but it'll also be running all day long. I'd bite the bullet and do it correctly up front.

YC1 · 02-01-2016, 01:02 PM

It would be marginal. Shutting the back half off and making sure you have windshield covering etc will work. I say marginal based on hot conditions. Being from Kalifornia and now Florida it would be uncomfortable. Shade would be important. I have owned a 30 footer with one. If you have double pane windows that would be a plus.

Mr_D · 02-01-2016, 01:06 PM

Mostly depends on the insulation in the rig. We never had a rig that size with only one heat pump. Always had at least two.

jodpel · 02-04-2016, 10:02 PM

I've got the 2015 version of the same rig as Mich F. It's an Itasca Spirit 31K. The one ducted AC works well. I live in Central Texas and it gets plenty hot here. I have three items that mitigate heat to keep her reasonable in the summer.

Replace all interior lights with LEDs. They use less power and run about 45 degrees cooler than incandescent bulbs.
Purchase a roll of Reflectix from Home Depot and cut a piece the size of each window. I store them behind the couch when we don't need them. I put them in the windows in the summer and trap them in place with the window shades. The ones in the cab I cut a little bigger than the windows and just stuff them in the opening and they sort of stick in the recess around the windows.
Purchased a white vinyl windshield wrap so the front is double covered between that and the Reflectix.

Put the carpet blind thing over the back of the cab to make the air conditioned space smaller. We find that a lot of heat is generated in the e450 cab. Trapping it up there helps. All those things make it comfortable inside but that A/C works it's tail off in August. It's comfortable, though.

My opinion is that 15K is enough and it's not worth the cost of another A/C and a more expensive generator and all that trouble.

Big Bear Local · 02-08-2016, 08:21 AM

I put a new 15k with heat strip in the front and put the old 13k in the back with a separate cord. I can run it off a genset or plug into pedestal if I need the second ac. So far I haven't had to use it.

JohnBoyToo · 02-08-2016, 08:40 AM

As you can see from the responses...
it's a definite maybe, sort kinda

you can NEVER have too much ac IMHO !!!

George Schweikle · 02-08-2016, 01:57 PM

We have a 29 ft. Safari Trek with one ducted A/C and do this for maximum cooling:
- Double pane windows
- Aluminum material shade on the front windshield, and inside the bathroom skylight
- Lower awnings to shade side windows
- Insulating pillows in the roof vent recesses. Just like in cold weather, only you want to keep the heat out
- And if you are stopping after driving: open the hood - you will be surprised how much heat comes out, even with a class A

wildtoad · 02-08-2016, 02:37 PM

Close off the front cab as mentioned, make use of shade or make your own my using the awning, and start the AC early.

Mr_D · 02-08-2016, 03:00 PM

Quote:

Originally Posted by George Schweikle

- And if you are stopping after driving: open the hood - you will be surprised how much heat comes out, even with a class A

Yep, some DP's like ours, even have an over the road air con for the bedroom as well as the dash air.

wa8yxm · 02-09-2016, 07:36 AM

Like so many things it depends.. Right now I'm "Stuck" in S.E. Ga and a Zero BTU A/C is all I need today.. Baby it's Cold Outside per GA standards ((40F) as I type, so an open window and the Fantastic fan is more than enough, in fact since it's blowing I have heat on (1500 watt controlled). Come August I have a 13,500 and a 15,000 in a 38 foot RV and it's not enough during the day (OK for sleeping but during the day it gets up to aroud 90 in here) No shade here)

Normally I summer in Eastern lower MI (Thumb or just S of it) and even there I'm glad to be on a 50 amp site cause 15,000 is a bit ... Anemic.

cmalberto · 02-09-2016, 04:54 PM

For what it is worth, I went with the 2nd A/C and 50AMP service - The heat in the summer time here is in the mid 90s with gobs and gobs of humidity. On any day, the best I could do is 80 inside with the sun beaming down. Tried everything.

I bit the bullet and added another 15K in the rear and also 50 amp service installed. I chose to not go with a larger Genny. I can almost run both on low with nothing else but either way 1 running down the road is fine. Night time was never an issue so staying at a Walmart was always fine.

The only downside is that the coach wasn't designed for 2 units so you find that one unit or the other will out cool and ultimately keep the other from coming on...but man does it cool down quickly can hang icicles when I want to.

As good as the second unit is - I may have been able to get by with just the new unit as it is extremely efficient and runs circles around the older(2 year) Dometic.

My 2 cents worth.