Roof top AC

[John316]

One thing I did want to mention, after reading Bruce's post....We have thermostats on all of our roof airs. At night we usually set the fan on high and 65. Nice sleeping. Also, Liin is right, helps knock the engine heat down (and for us, there is a BUNCH of heat that radiates up).

FWIW

John

[gus]

I do pretty much the same as Lin, it is just too cold and noisy to use the rear unit at night.

There is no problem with lack of  white noise from the front either, buses are pretty small compared to a house. I like white noise, especially when parked in WM or truck stops, but those rooftop ACs are really noisy, a lot more than white noise, and I hate to have cold air blowing directly on me in bed.

[Lin]

Bruce, I was not saying that I am planning on trying it, but merely that I think about it sometimes.  I have seen units that claim to be 10,000 BTU or a bit more.  I am suspicious of the claims though.  If I were to do it, it would not be a permanent install but rather something removable for the winter.  You would, as you mention, have to duct the condenser air or you would be heating rather than cooling.  I think different people on the board have tried these units with varying results that range from totally useless and up.  I think it was Bob Glines that did something creative with one that came out good.

The trouble with rooftop units is the air velocity.  That is what makes them so loud.  The system itself, which is blowing a lot of air into a little plenum with louvers back and front is not efficient to begin with.  Add to that the desire to throw that air a large distance in order to cool a larger area, and you get a relatively high noise level.  Ducted rooftops are quieter.  I suppose, since the compressor in the rooftop unit is just on or off, if one could figure out a way to get finer control of the fan speed and lower it to a peaceful level without the evaporator coils freezing over, you'd have a pretty nice improvement.

[luvrbus]

American RV sell the 641916 Penquin it only comes ducted with a wall mounted t stat I checked on 1 last week they are not really 15,000 btu but a 13,500 with some kinda of upgrade I passed on it as I need a cover type with the T stat 

Finally I bought a Coleman  lo/pro sure do miss the Carrier that would have been my 1st choice

[Gerry H]

Thanks all for your input, keep it coming please. I appreciate the interesting advice about where to put them, not put them, noise and air flow, but still have some questions. Several have mentioned putting them as far forward as possible, but isn't that for the driver's benefit while driving and not when parked?
   I'm intrigued by Gus's statement about putting one in the middle to forward area. I have considered just that since my roof isn't raised (I'm 6'1") and it would "bother" me to have something hanging down from the center of the ceiling just above the last step up to the living room, so everytime you enter/leave the bus, you have to "duck". I thought about putting the main one between the kitchen and living room while keeping the entry and living area ceiling as open and uncluttered as possible. I could then use a Haier (USA made) 10K portable in the bedroom. Yes, dedicated 10 ga wiring (main AC) and separate breakers. 12 ga/20A for all my socket circuits - (I have a wife)
  What about the Dometic heat pump option? Is it a worthwhile upgrade or expensive limited use option? I have yet to work out a heating plan for when parked, but leaning towards electric rather than propane for safety. Not planning on any ski trips-too old and fragile. And yes, Carrier would have been my first choice also. Seems everything "good" goes away.
  Thanks again for the advice Gerry H

[robertglines1]

I used a 20 inch ceiling fan from lowes above drivers seat. ceiling hugger. reversible.  felt good and broke up air layering in coach. 89 xl.  had light below it. never hit it.  $45  Bob

[garhawk]

Hey Gerry,

Lately I had a conversation with my friend Pete Papas who informed me that he owns a small Honda 2000w generator which he uses for emergency power to his house.  When the power goes away (in Florida) he runs a window AC unit in the bedroom, the refrigerator and whatever lighting is necessary.

Here's my rough plan, as soon as I find some spare time.

Buy the Honda 2000w.  New price locally is $915.  The specs on the Honda says it operates under 60 dba.  That's almost as quiet as a mouse pissing on cotton.  Runs for 4 hours under full load on 1.1 gallon of gasoline which, by the way, is the unit's fuel capacity. 

Pete says he uses a 7 gallon marine outboard motor tank plumbed to the little genny.  Now we're up to 30 hours or so at 16.5 amps.

So, my thinking is to mount the Honda 2000w, along with the 7 gal tank, securely but removeable in the Eagle.  The bus is equipped with OTR air along with three thermostatically controlled zoned rooftops (front, middle and bedroom) which makes for comfortable temperatures when driving, plugged into pole or, running main 15,000w generator.

However, for those nights when AC is needed and no pole is available, the 2000w Honda can accept a 115 power cord from the bedroom AC and blow cold air - quietly and cheap!  Figuring gasoline at $3.25 per gallon, that's 8 hours of sleeping under the AC for $6.50.  WOW, parking at Wally World, or the like, will be akin to stealing when compared to KOA.

The coach's battery bank will be responsible for the lights, tv, microwave, etc. and, will surely be replinished within a couple hours driving the following day.  If you plan to stay put but be away from the coach during the next day, leaving the Honda running for the pet or, just to keep the inside tolerable until you return, the economics are good.

Basically, I'm suggesting to optimize the current produced by a generator.  I know, the $1,000 or so for the Honda 2000w and the tank will buy a lot of fuel for the big generator but, I get to use the little suitcase genny for other things, too.  What y'all think?

[Lin]

I had thought of getting a similar generator instead of using my 7.5 Kohler when boondocking, but decided that it was not worth it at this time.  Costco has a generator the claims to have similar specs for about $450.  If it's a dog, Costco is great on returns.

[garhawk]

Hi Lin,

Agreed the Honda is a might(y) on the high side but, I've owned and dealt in Honda motors for more than 50 years.  Although a bad apple shows up occasionally in any bushel, Honda engines are very hard to top. 

Their warranty is acceptable, dealers are plentiful, parts are readily available, it is super on fuel consumption and, 59dba at full load is far below any claim I've seen from their competition.

My brother-in-law has a popup trailer with a single AC.  He swears they sleep like babies with the Honda 2000w running the entire night.

I have no financial interest in Honda - or any other interest for that matter, other than as a user.  It's just that I'm convinced that it is the best buy.  I'll certainly listen to any other opinion if it beats their reputation.

[Gerry H]

Somehow my thread on roof top AC turned into a Honda generator discussion?

[robertglines1]

Heat pump ac ?  If you are pole to pole then elect heat option(heat pump) would be great. Most camp grounds short stay do not charge more for elect.  Where we rent by month we pay elect heat and find it to be less than or friends using propane in the end. Just our experience. If you boondock allot, all bets are off.   Bob

[gus]

Yes, it is only necessary to install one as far forward as possible if there is no bus system, which includes most of us. You are, indeed, fortunate to have a working one.

I am also 6'1" but don't find the ACs any problem, I'm so used to ducking from shipboard life it just comes naturally. And I do have one right at the top step!! Anyway, they don't intrude much anymore, newer ones are pretty thin. You can always install it a bit to the side instead on centered. But, it really isn't a problem.

You don't need or want an AC in the bedroom, portable or not. I can't emphasize this enough!

One AC will cool just about any bus at night. I'm sure there are desert exceptions but I've never used more than one even though I've always had two installed.

Ideal heating is by propane furnace. It uses minimum 12V DC power for the blower and LP for heat, all exhaust is out the side  of the bus. Most SS RVs use these and with windows closed there is minimum danger. Electric heat requires a lot of amps so you either have to be hooked up or run the genset. I'm much more afraid of the genset exhaust than LP. I suppose you can have a large enough battery pack to run them but it would have to be pretty big and there is a lot of loss via inverters.

[robertglines1]

Actually Gus and I agree! depends on how you use your bus.  I now use inverter type air/heat system but am 95% pole to pole.   So differant strokes for differant bus nuts.  Bob

[belfert]

Finally I bought a Coleman  lo/pro sure do miss the Carrier that would have been my 1st choice

I'm curious why you like Carrier?  I have two 15K BTU, but my front one never really worked quite right.  I eventually replaced the front one with another brand.  I do like that the interior cover is much sturdier on the Carrier than the other brand I bought.

I am seeing a lot of complaints about Carrier RV air conditioners on another RV forum I frequent.  Some of the complaints are about blower wheels that break often, but someone is selling an upgraded replacement.  I've read that Carrier is out of stock on a lot of parts already.

[luvrbus]

I never knew anyone having problems with the Carrier Lo/pro units I like the way all Carries use the condensation water myself YMMD  

The Advent unit is making a move here you are seeing more and more of those units every day

I never could find a lo/pro in the Advent or Gree I would have tried one  you don't have to buy Coleman or Dometic for roof tops