Today’s Roof Air Conditioner Choices
If you're new here, you may want to subscribe to our E-mail Digest. We will then send you the stories that are posted each day in an e-mail digest. We use a service called Feedburner for delivery of these emails. You will receive an e-mail from Feedburner after you subscribe and you must click on that email to activate your subscription. Thanks for visiting and enjoy all the information!
RV.Net Blog Admin
Air conditioning is something that many of us have come to expect, whether it is in a house, car, office or RV. In many cases it is no longer an option as it once was. That is the case with most, if not all, motor homes and trailers today. While there are also manufacturers that mount the A/C units in the basement, we will only deal today with roof mounted. There are, and may be, configuration choices with options when it comes to ordering a new rig or replacement A/C unit. The selection may include the number of units, output capacity, heat strips, heat pumps, height profile, air ducted and possibly the thermostat control type. While many of these will probably not be a choice when purchasing a new rig, it is possible that a couple may, particularly if you are ordering a factory build. Let’s look at these choices.
Number of Units: Single A/C units are standard on Class “C” and “B” coaches, most trailers and shorter, entry level class “A” coaches. Larger class “A” coaches usually come standard with two units. The largest group of class “A’s”, 42′ to 45′, generally come standard with three A/C units.
In some cases, for those with only one unit, an additional unit can be ordered. This would apply to the class “A”, the trailers and possibly larger “C’s”. The “A” coaches equipped with two units may be able to specify a third A/C. Keep in mind, many of these upgrades may require changes to internal wiring and or, generator size, which may add considerably to the cost.
Output Capacity: There are several sizes, all rated in B.T.U. output, but the most popular being 13500 and 15000. Generally these require about 14.5 amps and 15.7 amps respectively, of AC power to operate. This however, can vary with different manufacturers. As the output is only about 11% difference, it is difficult to differentiate the two inside your coach.
Heat Strips: Are exactly what they sound like, they are heating elements within the A/C unit. Typically these provide about 5600 B.T.U.’s of heat when in use. These are not generally used on ducted A/C installations.
Heat Pumps: Heat pumps do not use heating elements. They basically reverse the A/C cycle exhausting the chilled air outside while warmed air is directed inside. These are very efficient and work well down to about 40 degrees F. outside temperature. Most heat pump set ups in today’s RV’s are wired to automatically switch to another heat source such as a furnace or HydroHot/Auqua Hot when outside temperatures warrant it. Likewise, they will re-start when the temperatures return to above 40 degrees F.
Height Profile: There are two common profiles, standard and low profile. The standard units project 12″ to 13″ above the roof, while the low profile is about 9″ high. Advantages are less wind resistance, can contribute to a lower overall vehicle height, and appearance.
Air Ducted: In most, if not all RV models, this is not a choice as it either comes that way or it does not. This is a good feature that can more evenly distribute the air throughout the coach.
Thermostat Selection: In some cases an optional remote thermostat can be purchased. This can provide the convenience of being able to set and monitor the temperature in any location within the coach. It may also provide a more precise control than that normally installed.
Anyway, that’s a brief simple version of what’s out there. Whether you are ordering a new recreational vehicle or replacing a worn out air conditioner, these are some of the choices and decisions you may have to make.
With More Cool Ideas - Lug_Nut
Last 5 posts by Lug_Nut
- Not All Tag Axles Are Built The Same - November 16th, 2008
- Justifying A Tag Axle On Your Next Coach! - November 9th, 2008
- Ways To Reduce Fuel Costs: Another View #2 - November 2nd, 2008
- Ways To Reduce Fuel Costs: One Method #1 - November 2nd, 2008
- Is Synthetic Engine Oil Worth The Buck$? - October 26th, 2008
I am a newbie and just ran the air for the first time last week. Is it common for water to flow off top of the RV while running the AC?
Like most AC units water coming from the unit is common. The higher the humity the more water.
Don
While it’s normal for the water to run down the sides of the motorhomes and generally make a mess there is no reason it has to be this way. Why not drain the AC condensation into the black or grey water tanks or at least have some kind of drain tube to the underside of the motorhome. It’s ridiculous to me to have a $200,000.00+ motorhome and have it running water down the side of the motorhome leaving ugly streaks behind just cuz the manufacturers are too lazy or cheap to make them drain cleanly.
[...] Today’s roof air conditioner choices [...]
If a little bit of water bothered me that much ! I would have my RV dealers shop custom install a drain line on your coach to you liking.
Drainage is normal. To minimize the streaking on the side of your camper, purchase some inexpensive gutter extensions and attach them to both sides of your gutter on each side of the camper. We have found them to work well and they have basically eliminated dirty streaking down the sides of our camper.
Could you touch alittle on theomstats for RV’s. I have a fiver TB and do not cool or heat the garage area. I would like to have a digital theomstat for better control of the living area.
Would you think that Wal-mart would carry something like this or do you have a website I could look at.
Curt, There are a number of digital thermostats that should work and answer your needs, however it would be wise to verify with the manufacturer of the trailer or AC unit(s), the wiring diagram used. Here’s a link for a unit that is compatable to Carrier AC and RV furnaces. http://www.jcwhitney.com/CARRIER-WALL-THERMOSTATS-WIRED-A-C-CEILING-ASSEMBLIES/GP_2014906_N_111+200736069+600002282_10101.jcw
I have a large s.u.v. that I can not the a/c to work, have brought to every mechanical and electrical individual I can think of, can you advise if this small low profile will work on a s.u.v. that is a 16 pass, and can it be mounted to the roof, and since this item is A/C will it work in a truck situation or will I need some kind of power inverter, which I trying to avoid. Thanks for taking time to read this.
Guy, It would be not possible for me to advise you on this given the information you provided. However, I would think a small roof mounted A/C unit powered by a small suitably sized gasoline generator would be one solution. The generator would have to be mounted in a well ventilated location with an unrestricted exhaust outlet outside. Best in an outside compartment.
my RV AC isn’t draining. Can you tell me how to locate the drain hole so I can be sure it’s clear? The unit is a carrier brand.
Hi Cheryl, If your AC unit is working well, and cooling, there will be condensation coming from the unit. Your statement “My RV isn’t draining” leads me to ask, “where is it going then”. Your AC unit may require cleaning. I would have it serviced at a local AC service shop.