House doesn't cool down enough

[Jackie]

Our problem is multifold and I am hoping for advise.

Last year we purchased a 2000 Cavco double-wide, with 1400 s.f., in Arizona. Once the summer temperature climbed past 90, our 4 ton central air conditioner stopped cycling and struggled to maintain an indoor temperature of 72. (We use ceiling fans throughout, too.) As the temps climbed the a/c couldn't handle it and the coolest we were able to get our home was 78 degrees during the day. At night, with no sun load and cooler temperatures, it returned to cycling and cooled the house down properly. Needless to say, our summer electric bills were off the wall and worse, the house still wasn't as cool as we wanted it.

We noticed many homes out here, including older mfg homes, use an evaporative cooling system. We thought perhaps that would help during the dry months. We called in several contractors for estimates. We received two estimates in the $2200 range. Two other contractors told us they wouldn't even install an evaporative cooling system in our home. One said it would create too much moisture and eventually rot our home; the other said we needed a bigger a/c unit instead, so it would cycle properly, and not an evaporative cooling system.

We realize we would be unable to use the "swamp cooler" during monsoon season, but thought it would help during the other hot months and save us considerably on our electric bill and also cool the house down.

We are also wondering if replacing windows or adding awnings to deflect some of the direct sun would help and if so, would it help enough to justify the cost?

In the meanwhile, we're dreading another summer here.

Your thoughts are appreciated.

[Mary]

One thing that helped us considerably here in sunny and hot central California is to add solar film to the windows that get direct sun. It cuts an amazing amount of heat and we noticed immediately that the power bills went down. It also seems to help in the winter holding the heat in (as it does get cold here too).

The film is expensive ($45 a box) and terribly difficult to apply; it's sort of like aluminum foil membrane, and you can't make mistakes or you start again! I was so angry at the difficulty that I wrote the company. Apparently there is easier film available. I guess I didn't look far and hard enough. Anyway, we got it done.

We also use ceiling fans throughout the house, and dress in shorts and t-shirts at home. We also go down to the pool whenever possible.

As far as the AC cycling, etc. I cannot address that. Ours seems to work fine and I am very grateful! I think awnings also help, and so do shade trees. We have awnings but no trees.

Good luck to you.

[David Oxhandler]

Check out the
heating and cooling web section of Mobile Home Repair.com.. Whether you are searching for an AC part, tips and information on repairs and maintenance or help with troubleshooting, CLICK HERE NOW!.

[Cliff]

I always naturally assume that others are not as ignorant as I, so you've problably checked this, but I had a similar problem in West Texas. I even had an air conditioner repair person check it out and declare that the unit was doing what it was supposed to. One day my wife happened to be working in a flower garden near a vent in the skirting and noticed cold air. I crawled under the house and found that the duct work from the fan to the rest of the house had come loose and there was a three or four inch gap. Most of my cool air was blowing under the house! I repaired it with duct tape and now it cools fine. I went one whole summer sweltering in 100 degree heat and thinking I just didn't have enough AC!

[rmurray]

I do not think I would call that a/c repairman again....He missed a fundamental problem..

[Jackie]

Thank you so much for your responses.

We did check to make sure the duct work was intact. (Anyone could have missed that, Cliff!)

I forgot to mention: we use hotel grade black-out drapery liners, which probably serve a similar purpose as window film. (You can't see out the liners of course, but we thought it would also help around the window frames if that were part of the problem.) Even with the liners, I have noticed that our rooms seem just a tad warmer near the windows than in the center of the rooms. It could be my imagination though, since the temperature difference doesn't register on a thermometer.

Thank you for the a/c & heating repair link. It's great! I searched back through all of last summer's posts and did not see my issue addressed, but will ask there too.

Unfortunately, we can't afford to replace windows, add awnings, put in an evaporative cooler and replace the a/c unit. They're all rather pricey and since we can do only one of them, I am still looking to see which would make the greatest impact.

Thanks again.

[Kurt]

I would think that a 4 ton unit would be plenty big for the size of your house. The house should be well insulated as it is a fairly new house. Are the inside evaporator coils icing up when the unit runs? Is your outside condensor unit located in a shady spot with plenty of clearance around it for good air circulation? It also could be something as simple as your system being undercharged. I assume that you have had an HVAC guy check out your system and he should have checked this stuff. Good luck.

[Jackie]

We were told the system is properly charged and nothing seems to ice up when it runs. It is NOT located in a shady spot though. It gets full, intense sun all day long. Does that make a difference?

[Kurt]

The system is very reliant on the air flow through the outside condensor coils to remove the heat from the superheated refrigerant and condense back to a liquid. This liquid is then metered through a valve into your evaporator coils to be boiled off by the heat it absorbs as you try to cool the house. More heat is also added simply by the act of condensing the refrigerant. If the refrigerant cannot be cooled back to a liquid, it will not function as it should. Possibly, some sort of sun shade over the top of outside unit might aid in cooling. Just make sure there is plenty of clearance for airflow around and on top of unit.

[EB]

Kurt is suggesting an awning of some kind, which you have stated you can not afford. The condensing unit in direct sunlight all day is normal here in AZ. Most older homes have roof top units and i've seen many last well past 10 years and work fine. One rule of thumb when cooling in AZ is you should never set your t-stat more than 30 degrees below ambient. Even at 30 in this heat you are asking alot from any unit.
Welcome to the desert!