Upgrading Roof Air Conditioner

[John503]

I have a Monaco Monarch 30PPD and it is equipped with a single 13,500 AC unit. Being completely ignorant about these things I need some of the professional advice from members. My quest is this-- What would I need to do to up grade this 13,500 AC to a 15,000 AC, or is this even something that can be done with minimal problems. While the 13,500 does cool as it is designed, I just feel a larger unit would do a better job overall. It seems as if the 13500 does not have enough push to get the air to bedroom area as it should. There is air coming from the bedroom ducts that is cool but just not enough of it to do the job right. Any help appreciated. Thanks John

[wolfe10]

John,

Replacing the 13.5kBTU with a 15.0kBTU is not difficult at all.

The roof hole is the same size for each.

You can check with your coach maker to verify the amp rating of the wiring and check the 120 VAC breaker for the 13.5kBTU unit.

15.0kBTU units are made in "regular" and "energy efficient" models. The energy efficient units use less power and may require no wiring modification. But, even a regular 15kBTU may not require wiring upgrade-- that you will need to confirm with your coach maker.

Do not expect a large difference in output. Before spending money for this (other than at the time you would replace the unit anyway), I would look at insulating the windshield (a large source of heat, particularly if facing the sun), adding window awnings to keep the sun off them, etc before spending the big bucks on a new A/C when the current one is functioning properly.

You can also add fans-- either 12 VDC or 120 VAC to help move air around.

Brett

[BIXLER]

I have the same unit and improved the output by taking down the grill, and using tape to close the cool air from leaking and being drawn back thru the evaporator.

This improved the output by 50%.

[John503]

Thank you both for the suggestions and information. I had kicked around the idea of the window awnings but never did them. My last MH had them on all windows and it was the same size as I have now but it seemed to cool much better. Now might be a good time to install them. I dont have the solar screen for the front windshield but I will pick one up and give it a try. I will also try the tape and see what happens. When you taped it up, did it improve the airflow in the rear ducts? I have checked ducts for any obstruction but found nothing. It just appears there is not enough force to push air out in a decent quantity to cool properly, the rest of MH is fine. I use a small fan to help circulate air and for the noise it makes to help drown out outside noises. Again, thanks for the info.

[Guest BillAdams]

If you think closely about the numbers you would only be gaining a 10% increase. 13.5K BTU vs 15.0K BTU. The end result is unlikely to be dramatic (but it will be costly) so I would seriously consider other options for keeping cool air in and/or hot air out.

[tbutler]

Regarding the problem of getting air to the bedroom, it may not be a factor of having enough force to get the air there as much as it is a problem of letting too much air come from vents in the front of the motor home. If the vents in front are full open then the bulk of the air will escape nearest the air conditioning unit. Closing some vents or partially closing them will result in forcing the air to the bedroom. You could just do this on a daily basis. When you will be in the bedroom, close off several vents in the front of the motor home. This should result in greater air flow to the bedroom.

I am a strong proponent of using sun screens on the windshield and the other driving area windows that don't have awnings. Louise always comments how she can feel the motor home get cooler right away as I install the sun screens on the windshield and the drivers and passenger side windows. Awnings are essential for all windows if you feel your air conditioner performance is marginal. They are the most effective way to keep heat out of your motor home. Windows are the least insulating surface on the motor home. Covering them from direct sunlight will greatly reduce the heat that comes into the motor home. Slide out toppers also greatly help reduce heat in the motor home.

There are other things that can help with keeping temperatures comfortable in the motor home. Park with the windshield facing north if possible. This helps even with a sun screen. Select a shady site if one is available. Use window curtains and day/night shades to help keep heat out of the living space. After driving, open the engine compartment cover if possible to allow greater air circulation and faster cooling of the engine. The same goes for the generator compartment if you have been using the generator. Cook meals outdoors when convenient. Eat cold meals when you can. Shower in the campground showers rather than in your motor home. Turn off any unused lights. Keep TV usage to a minimum. All these things will reduce the load on the air conditioner.

[John503]

Tom thanks for input. I don't have window awning but will most likely go ahead and add them. I will also get a good sunscreen. I have already tried the closing off of the front vents but that helped very little. Currently we use a fan to help force air to bedroom area and this helps about as well as anything I have tried. Again, thank you for your advice. John 2006 Monaco Monarch SE

[BIXLER]

By taping the air leaks I got more air to the rear vents. Also get the insulating foam blocks that go into the roof vents this makes a big difference. solar covers on the windshield make a big difference . When you take the cover off the AC turn it on and you will feel the cold air blowing into the air return. If you want to contact me Email MB98ULTRA@AOL.COM