Adding/moving Air Conditioning units?

[cncsparky]

Searched and didn't find anything, sorry if its a newby question       My coach has a single coleman AC unit that seems to be on its last legs, wouldn't keep up late last summer.  I believe its original.  The unit is mounted in the center of the RV.  Looks like most RV's starting in the 29-30'area have 2 AC units.  One thought I had was to move the main AC unit to the front vent (already a vent but power?) and install a smaller unit in the rear bedroom where there is a powered vent already.

1. Does this sound reasonable to do?
2. The area now occupied by the old AC unit, how hard to install a regular vent in its place.
3.  Best way to wire in an AC unit when there is no wiring now.

Thanks!

[Stripe]

1: Yes, most RV's are prewired through the roof for the addition of AC units(A/C) or powered vent's (D/C).  I know my 77 is and my 84 as well.

2:  Replacing the AC: Easy if you have help getting the AC unit up on the roof in the first place.  The only thing that holds it down when you first put it up is gravity.  No sticky gaskets.  Just a closed cell foam rubber gasket to seal out moisture as in the example in this link,

http://www.rvplus.com/ventmate-air-conditioner-seal-14x14-40111.html?utm_source=googlepla&utm_medium=cse&utm_content=CS-62901&utm_campaign=googlepla&catargetid=1932358625&cadevice=c&cagpspn=pla&%22cagpspn=pla%22&gclid=COL8jcDYkbgCFcU5QgodrC0APg   

Once the AC is in place and where you want it, go at it from underneath next.  There are usually 4 very long bolts that connect the power and controller frame to the main unit. A vinyl hose that connect the main unit to the frame to make a vent and then the plastic ceiling cover to hide it all.
Replacing with regular vent:  even easier and lighter.. and no wiring to worry about unless you want a vent w/fan.

3: Best way to run wiring when there is none, Hmm, I would probably say splice into the old AC units wiring and using a long bendable metal rod, run it through the roofing, but be aware, you may have either foam or padded insulation up there so be careful when pushing/pulling the rod through it all. Other than that idea, if you ABSOLUTELY had to, take the ceiling and possibly the wall leading to the power distribution box, down and go that route.

But I will bet there is already wiring where you need it.  If your wanting to put an AC unit where a vent is now, it isn't very hard at all to remove the inner shroud from under the vent and do an inspection of the area.  Be thorough, the wiring me be above the insulation.

Hope this helps

Fredric

[cncsparky]

Thanks!  So if its pre-wired, I assume the wire is big enough to handle an AC unit?  The vent above the bedroom is powered, I wonder if it has large enough wire already for AC.

If a second AC unit is added, wouldn't it be too much for my 30A service?  I notice regular 110VAC outlets at most campgrounds in addition to the 30 RV outlet, can I set it up to run the second AC unit?  Basically two cords going to the hookup box, one 30A and one 110V for the AC unit?

[pvoth1111]

There are new and used ac's on ebay...great prices 300 bucks for 15000 btu's, free shipping

[moonlitcoyote]

Basically two cords going to the hookup box, one 30A and one 110V for the AC unit?

I like that idea, cant wait to see some replies on that one

[DaveVA78Chieftain]

A typical 13000 btu AC will draw
Starting: 2500 Watts  (20 amps),
Running 1700 Watts: (14 amps) 

Lets say one is running at 14 amps and the starts up at 20 amps.  Thats 34 amps which is above the 30 amp rating of the rig.  You also have to add in things like the converter,  microwave, and toys (TV, computer, etc.)  So I hope you can see why almost all 30 amp rigs with 2 AC's are not set up to run both AC's off of shore power.  However they typically have a 5 to 6.5 KW (> 4K) which is split into 2 seperate outputs.  One side runs the rig at 25-30 amps and the other side runs the additional AC (20 amps).

Can you run a seperate power cord from SP campsite 15 amp hookup?  Yep, but some campgrounds may charge you extra if the discover it.  Only consideration would be if the extra 15 amp circuit is on the same supply leg as the 30 circuit.  That might trip another breaker farther up the power chain.

Dave

[Stripe]

I have done this.  I wired an old three wire extension cord that I cut the female lead from, hooked it into my AC from the inside, ran the wire out a side window and plugged it into same power box as shore power. Now keep in mind this was at a WA State campground so they don't usually charge extra for the other plug. Both plugs were in the same junction box.

As Dave says, some RV's were not wired to run two ACs.  Although some RVs have two AC units, what I have seen is that one works off shore power and the other off the generator only.
Hope this helps
Fredric

[cncsparky]

Ok that helps.  Maybe best,for me, to replace the current AC unit with a new one and see if it cools adequately before moving them around.

[ClydesdaleKevin]

Just my two cents before replacing the old AC unit...have you cleaned out the filters and the inside and outside aluminum fins?  If they are clogged up they will seriously hinder the cooling capacity of the AC unit.  My 2 year old Coleman was dripping water into the rig and not cooling nearly as well as it had 2 years ago...I cleaned out the drip drain holes and discovered the inside fins were almost completely clogged.  I cleaned them out, and voila...like new again and blowing super cold!

If you do decide to replace it, your rig is only 29 feet and 2 AC units at that length would be serious overkill.  A 13.5K unit functioning properly should cool down your entire rig on even the hottest day...and if you are really want cooling capacity, go with a 15k unit...but 2 units are a bit much at 29 feet.  Our front unit, 15k, cools our entire 35 foot rig no problem on the hottest days we ever encounter.  We rarely use the rear unit at all, except to cycle it to keep it running well...we might replace it with a swamp cooler at some point for desert boondocking.

Ditto on the wiring...there should be 120 volt wiring to the vents, as well as 12 volt wiring if the coach was well designed, and since yours is a Winnebago, chances are the wiring is there.

Our AC units go to a selector switch in the power compartment. In one position only the front AC unit works.  In the center position they are both shut off.  In the rearmost position, the rear AC unit is the only one that works on shore power, but both will work on generator power.

Kev

[serenitygirl64]

Question.... my ceiling unit condenser is bad and I was considering removing the unit all together and using a free standing 110 unit that you vent through a small opening and putting in a skylight where the roof unit is.   Last 3years I have been using a small 110 window unit and found I use less wattage.  I am a full time RVer and was thinking of the weight difference I would be eliminating.    Hm? Any thoughts?

[cncsparky]

Thanks Kevin!  Sounds like I will keep my original unit/location for now and look for a replacement if necessary.

[Oz]

I am a full time RVer and was thinking of the weight difference I would be eliminating.    Hm? Any thoughts?

The roof air, if was a 13,500 btu unit weighs in at @ 100lbs.  I'm not sure of the weight of a free-standing unit but, I would hazard to guess you'd cut down @ 50lbs in the deal.

[moonlitcoyote]

I just bought a free standing AC unit that vents out the window with a 6in pipe. It weighs 53 pounds.

[serenitygirl64]

thank you Moonlitcoyote.  I appreciate your input.  As a full timer I always have concerns of weight and look for ways to reduce some of the weight and I was also considering I don't usually do full hook-ups and my genny is easier on fuel running 110 A/C.