One or two acs

Topic: One or two acs (Read 988 times) previous topic - next topic

One or two acs

September 12, 2020, 04:42:35 pm

I am a prespecative buyer. Looking hard at the Foretravels. I would want a unit in the 34-36' range. Do this size need two acs?

Re: One or two acs

Reply #1 – September 12, 2020, 04:57:23 pm

Welcome to the Forum! Expect a wide variety of opinions here...on almost every subject. We respect every member's opinion.

What you "NEED" and what you "WANT" are sometimes two very different things. As far as I know every Foretravel coach has been fitted with a minimum of 2 roof air units, at least since the early 90's. Do they all NEED 2 (or more) units? Matter of opinion. Depends a lot on when/where the owners habitually camp. Summer or Winter? Mountains or desert? Do they mostly dry camp, or always stay in full hookup parks?

Having 2 units gives you 2 "zones" that can be (somewhat) independently controlled. Shut the bedroom or bathroom door to keep one end cold and the other end warmer, or vice versa. Having 2 units means you have a backup if one fails. Coaches with ducted A/Cs can run the unit at the end where you are not sitting and pipe the cold air to where you are sitting. Helps keep the noise level down.

Link below to Foretravel specs where you can compare different models/years:

Foretravel brochures, specifications and manuals Information Links

Re: One or two acs

Reply #2 – September 12, 2020, 05:02:10 pm

Main reason for my question is because first upgrade will be mini split/s. I was thinking with 34-36 i could get by with 1 unit. Even if it is an 18k.

Re: One or two acs

Reply #3 – September 12, 2020, 05:26:02 pm

I feel like my comments above can apply regardless of what type A/C unit is installed.

Some owners, in some situations, could get along just fine on one unit. Other owners would find that limitation unbearable.

Re: One or two acs

Reply #4 – September 12, 2020, 05:29:30 pm

And, a lot of the answer will depend on the climate where you intend to use the coach.

Mountains out of Denver are VERY different than the temperatures and humidity on the Gulf Coast.

We just returned from two months in Angel Fire NM. Even the million dollar homes there do not have A/C. In the Houston area, everyone has BIG air conditioners!

Re: One or two acs

Reply #5 – September 12, 2020, 05:39:58 pm

Our 2001 36 ft has two AC units and ducting that runs front to rear. Most often if we need to we will run the rear AC only. Accolair comes out the outlets in the ceiling ducts. We have a ceiling fan in the BR and rarely run any AC at night. If it is really hot we can run both.

Re: One or two acs

Reply #6 – September 12, 2020, 05:58:04 pm

I would not be in south Texas/Louisana in summer unless visiting my daughter. I ould go to cooler less humid areas.

Re: One or two acs

Reply #7 – September 12, 2020, 06:38:16 pm

We have a 5 head Mitsubishi mini split upstairs at home and we absolutely love it. To adapt that for the coach would be far too much engineering and would use space very inefficiently it seems to me. With the units that come on it you only use up roof space and like was pointed out you have a backup unit in case of failure. We love our mini splits at home but I wouldn't consider them for the coach.

I'm not sure what is available for 110 but that is another consideration.

Re: One or two acs

Reply #8 – September 12, 2020, 07:36:45 pm

I have removed both rv acs on current 5thr and installed two mini splits. Don't see where it would be any different on a Foretravel. Also are all posts always have to be approved before showing up?

Re: One or two acs

Reply #9 – September 12, 2020, 09:20:47 pm

Quote from: GlennWest – September 12, 2020, 04:42:35 pm

I am a prespecative buyer. Looking hard at the Foretravels. I would want a unit in the 34-36' range. Do this size need two acs?

We live in south eastern Georgia in a 36' GrandVilla, and when the temperature goes above 90F both ACs are on. Right now with daytime temperatures in the high 80s, and the morning low in the mid to low 70s, the front airconditioner stays on all night mainly as a dehumidifier.

Yes, you need two air conditioners.

Re: One or two acs

Reply #10 – September 12, 2020, 09:53:22 pm

why would anyone choose 1 ac when they all come with a minimum of 2 in the length you are looking for.

Re: One or two acs

Reply #11 – September 12, 2020, 10:07:13 pm

Because I will do away with both of them. Make more room for solar. Put mini split system in. I see from these posts that these units are harder to cool than my 5ther. That is disappointing. At 90 degrees I can cool my 40' unit with 1 12k mini split. Above that it takes two. It will also take a while for my post to show up.

Re: One or two acs

Reply #12 – September 12, 2020, 10:24:10 pm

Quote from: GlennWest – September 12, 2020, 07:36:45 pm

Also are all posts always have to be approved before showing up?

Think that is just when you initially join.

Re: One or two acs

Reply #13 – September 12, 2020, 10:38:29 pm

Like everyone, we have two units in our 34'. I would like to add one more over the driver for those hot long road trips in the summer.

After living all my life on the Gulf coast, I will never own anything I get inside of and sleep or drive without an AC.

Re: One or two acs

Reply #14 – September 12, 2020, 10:51:49 pm

Mini splits do cool better than rv units. Discovered that with my unit. Had 2 15k dometic on it. In south Texas it was lacking. 2 12k mini splits will freeze us.

Re: One or two acs

Reply #15 – September 12, 2020, 11:37:06 pm

Where would you mount the mini condenser?

Re: One or two acs

Reply #16 – September 13, 2020, 12:28:28 am

On my 5ther it is at the back on a frame I built. I would like to put it in a storage bay if possible. Don't have a unit to check out in my possesion. The interior unit is usually the question. I had several areas in living room on my 5ther but not the bedroom. Had to use a cassette ceiling unit in there. That is very doeable with a wood roof but Foretravel I understand are aluminum. Still doeable but more trouble. I am a welder though. Cassette are physcialy larger than rv acs so opening has to be bigger. You can tell me how much room is above cabinets if any. The mini split is very quiet and sips electricity.

Re: One or two acs

Reply #17 – September 13, 2020, 01:18:13 am

The storage bays would not have enough air flow for a condenser. the compartment opposite the start batteries would be to only place to not have to install it on the outside of the coach but even then lots of heat in that area unless muffler is removed. Also you know that the condensate has to go somewhere outside of the evap coil. I have a 18k btu. in my bedroom and yes they work great. It is a 230 volt as 12K was the biggest on 120 volt. Depending on the year coach you would have ducted or non ducted registers. Good luck and post if you find a way to make a mini work.

Re: One or two acs

Reply #18 – September 13, 2020, 09:46:33 am

I have not seen a condensor in the storage of a motorhome but have on bus conversions. I would have to have door open or put a screen in it. The back would have to have air flow. Maybe open up the back? Again I might just put it on rear. The U units look to have plenty of room for it. The roof is asume is 6-7" thick. That is typical. A cassette will set up about 7 inches. Run solar panels at 7 inches height. Cover entire roof. If generator produces split phase it would run the 240v units. If not I would have to add an autotransformer. But one can run mini splits off of solar and battery only. Not rv acs. But if I can find room inside for a wall unit I will use 48v mini splits. Then just keep coach 120v.

Re: One or two acs

Reply #19 – September 13, 2020, 01:07:57 pm

The 97 and up ducted roof a/c's allow a lot of flexibility and backup. The 97's and 98's and maybe 99's have heat strips not heat pumps. Backup for the coaches heating systems.

I understand with board and thermostat changes the coaches can be can be made to be a dual setback HVAC.

Plus the Magnum system can be fully integrated into their inverter/charger system including auto gen start from various adjustable system demands.

Heat, cool, battery charge all automated.

Adding a now industry standard battery bank auto combiner covers the normally separate chassis batteries charging in storage.

Repairing a mini split system would be seen to be more difficult than a rv roof air.

Versus the time and effort needed to retro a mini split into a coach body shell not made for it will not be easy.

A small series of Foretravel's without slide outs in the mid 90's had non roof air units in their bays as did a group of Winnebago coaches.

The current solar panels better output per size seems to allow at least 2k watts from a roof.

As I told a number of Foretravel customers long ago who wanted to change their ordered new coaches diffently from normal production "why don't you try the coach the way Foretravel built it?"

Giving up and opening a compartment for the condenser would seem to be the main obstacle. Plus the condenser would be next to the heat from the road surfaces...

Like I posted here a fully integrated HVAC/solar/ auto gen start would seem to be a doable for sure system mod?

The Magnum integrated system seemingly has the ability to prioritize the choices of heating for example. Could be set to turn on the roof airs heat pumps or heat strips if 110 available or the furnaces or aqua hot if no 110. Stuff like that.

Enough battery and solar to run a mini split reliably will be very expensive and with enough cloud cover the gen may need to be run.

Re: One or two acs

Reply #20 – September 13, 2020, 01:17:43 pm

Bob, I need some clarification from you if you would. You say heat strip and heat pump, my confusion comes from the term heat pump. My understanding of a heat pump, certainly where we live is static fixture on on a house that has pipes and heaven knows what else buried at least 100ft in the ground. This set up takes advantage of the constant ground temperature of 52 degrees.
Our coach has the ac/heat overhead.

Re: One or two acs

Reply #21 – September 13, 2020, 01:22:25 pm

There are a lot of owners running mini splits and solar. They are all 5th wheel though. On cloudy days they supplement with generator. As far as working on them, they are simple. I work on them. They are actually serviceable unlike rv acs. Capistor and fan motor about all you going to do to a rv ac. After that throw away. The condensor may fit on drivers side up front. Talking with a fellow Foretravel owner he thinks it will if muffler isn't real big. He's is small. Also those rv units are noisy and can't be run on solar. Well for not long anyway. Ours pull on average of 450 watts each. we have two. Also there are two rv manufacturers now putting mini splits in there units from the factory.

Re: One or two acs

Reply #22 – September 13, 2020, 01:26:35 pm

Quote from: Olde English – September 13, 2020, 01:17:43 pm

Bob, I need some clarification from you if you would. You say heat strip and heat pump, my confusion comes from the term heat pump. My understanding of a heat pump, certainly where we live is static fixture on on a house that has pipes and heaven knows what else buried at least 100ft in the ground. This set up takes advantage of the constant ground temperature of 52 degrees.
Our coach has the ac/heat overhead.

The heat pump he refers to is the newer A/C's have a reversing valve that makes the evaporator coil the condensing coil and produces heat out the same register as the A/C

Re: One or two acs

Reply #23 – September 13, 2020, 01:30:03 pm

Quote from: Olde English – September 13, 2020, 01:17:43 pm

My understanding of a heat pump, certainly where we live is static fixture on on a house that has pipes and heaven knows what else buried at least 100ft in the ground. This set up takes advantage of the constant ground temperature of 52 degrees.

What you describe (ground source) is one specific type of the more general category "heat pump". See link below:

Heat pump - Wikipedia

Re: One or two acs

Reply #24 – September 13, 2020, 01:34:38 pm

Also I don't want aquahot. Too much maintance and cost.

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