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leong1 · 06-24-2009, 10:03 AM

Hello everyone. I have a 1977 31’ Excella 500 which is out in the sun in S. FL all the time. Could I please ask a couple of questions about air-conditioning? I am presently living in my trailer and pretty much leave the air on 24/7, even when I am away at work during the day. On the few days that I have turned it off, the temp inside has gone up very high, making it difficult to cool down when I return in the late afternoon. Because of the heat here, I do have to keep the air running throughout the night. I have two questions about this:

1. Is it OK to leave the air-conditioning running day and night? What are the down sides to this, other than electricity cost? I believe I have the original factory-installed system in mine, which is really working well, except for very hot days when it won't cool down to below 80 degrees, but at night it's fine.

2. Is it better to turn off the air during the day when I am not there, to save wear and tear on the system? If so, how high will the temp go inside? What kind of “damage” can take place in the inside in such high temperatures? Will leaving the air off in the hot sun affect the operation of the fridge?

Thank you very much for your assistance.

adonh · 06-24-2009, 10:18 AM

Its OK to let the AC run, just adjust the thermostat down a little so the compressor can cycle on and off.

Don

leong1 · 06-24-2009, 10:30 AM

Thank you Don. When you say adjust the thermostat down a little, do you mean turn the thermostat colder or warmer? I keep it set at 73 degress F now. What temp do you suggest I turn it to? Should I turn it down to say 68 or up to say 78?

Thank you again.

Minnie's Mate · 06-24-2009, 12:04 PM

Welcome to the forums leong1. You will find lots of friendly advise here.

We frequently travel to Florida in the summer months and leave our A/C on 24/7 when we do. I purchased a surge guard after the first summer to protect the compressor from drops in voltage as well as surges. At the end of the first summer our circuit board on the A/C burned out. Fortunately, it was covered under warranty, but the service technician speculated that it might have been in a low voltage situation for too long.

When your A/C compressor comes on it draws a lot of voltage at the initial start up. When it's hot during the heat of the day while you are at work, everybody's A/C compressor is doing the same thing. Coincidentally, a lot of you in the same campground will have their compressors kick in at the same time and that will cause a voltage drop for everybody on the same electrical loop. When this occurs, your A/C might not have sufficient voltage to operate properly and this can cause some expensive damage to your unit. The surge guard that I bought at Camping World will shut off the electricity to the entire trailer when the voltage drops below a safe level until adequate voltage returns, or for a minimum of 2-1/2 minutes to allow the compressor to discharge the pressure it may have built up. I also keep a voltage meter plugged into one of our electrical outlets so I can keep an eye on the voltage level. The entire unit plugs into the 30 amp outlet at the pole and you plug your power cord into the surge guard. The surge guard will also check for reversed polarity at the pole. They aren't cheap, but the peace of mind and protection is well worth it. Also, I think they are on sale at Camping World right now.

Just a suggestion.

thecatsandi · 06-24-2009, 12:49 PM

When I was living in mine and on contract in Boise, it was 100+ for most of the month of July. I left the AC on all the time. I could only get the trailer down to about 80. I called the factory and they said for a trailer my size a 20 degree drop is about all I would see. If you have more than one powered vent you could turn off the AC and have one push in and suck out. That would keep it near 100 but the humidity would be high.
I blew one startup capacitor at the end of last season. The unit went through an unknown number of hard starts so I opted to have the AC unit replaced.

Diesel1 · 06-24-2009, 12:59 PM

If it were me I would leave it run( unless I could'nt aford the electric bill). I think it is a lot less strain to get things cooled down and keep them cooled down. the compressor and fans work much harder starting up then they do once they are running. Adios, John

**jcanavera** · 06-24-2009, 03:16 PM

The only other issue not discussed here is wear and tear on the unit itself. Obviously the more the compressor runs, the shorter it's life. The question is what is it's lifespan? I can tell you that I had a Duo-Therm Brisk Air on my Hi-Lo and it ran perfectly over the trailer's 14 year life under my ownership.

We have noticed in our subdivision that the folks who had home heat pumps usually had to replace their outdoor compressors somewhere after 9-11 years of service. Those of us with straight air conditioners got anywhere from 11-16 years of service.

Since I have a heat pump on my Classic, I would expect that its service life will be less. I do use the heat pump side when out in the cool spring or fall temps.

Personally, I have this unit for comfort and bottom line I'll run it regardless of how it affects the overall life of the unit. The only thing that would stop me from using it is a low voltage situation. That condition will kill your AC.

Jack

wahoonc · 06-24-2009, 04:26 PM

Couple of suggestions: If you have awnings...deploy them they take a massive amount of heat load off the trailer. FWIW I run my AC to my comfort levels even it takes 24/7. Also consider getting some Reflectix for the windows. It is a foil faced bubble wrap, I cut mine so it would wedge in the window itself. it is available from both Lowes and Home Depot. You can't see out, but it sure helps cut down on the solar gain from the windows, you can pull it out when you get home in the evenings. Maybe look for a campground with shade trees too.

Aaron

Minnie's Mate · 06-24-2009, 04:34 PM

On use of the awnings. Florida summer thunder storms, or other season for that matter, can dump a lot of rain on the main awning in a short amount of time and cause an awning arm to collapse so if you plan on using them when you are not there, either have them in the lowest notch or the rear one arm in the lowest notch so the water will run off as quickly as possible before the weight can cause a collapse. I have had this happen twice and nearly a third time while I was standing under it.

53flyingcloud · 06-24-2009, 05:26 PM

Quote:

Originally Posted by Minnie's Mate

On use of the awnings. Florida summer thunder storms, or other season for that matter, can dump a lot of rain on the main awning in a short amount of time and cause an awning arm to collapse so if you plan on using them when you are not there, either have them in the lowest notch or the rear one arm in the lowest notch so the water will run off as quickly as possible before the weight can cause a collapse. I have had this happen twice and nearly a third time while I was standing under it.

I would add this footnote..
Be sure they are securely anchored with a screw anchor and roped tightly.
Otherwise, my approach has alway been: to stow the awning away when planning on being absent from the trailer for any period of time at all..

It's that sudden high wind that gets you every time~!
ciao
53FC

richinny · 06-24-2009, 05:44 PM

i agree that the awnings help a lot but the wind will keep pushing and pulling on the hardware all day long.

can you park the trailer in a spot where the sun travels over it from east to west? (less mid day exposure)

someone here put a plant mister on top with a timer. i think it helped take the edge off the body temp. when trying to cool it down.

Lumatic · 06-24-2009, 05:50 PM

In high humidity with my AC on max I had my 13,500 Penguin actually freeze up. Now, if I'm not around I turn the thermostat down a bit.

**jcanavera** · 06-24-2009, 06:04 PM

Quote:

Originally Posted by Lumatic

In high humidity with my AC on max I had my 13,500 Penguin actually freeze up. Now, if I'm not around I turn the thermostat down a bit.

Interesting since I had a freeze up on my SOB when I was down in Destin. The AC repair facility noted that I needed to keep the fan speed on high. He said a lot of folks run the lower air speed which tends to cause a slower air movement through the coils, which in turn allows the coils to be a little colder. Mix in a good dose of Florida humidity and you start to get ice formation. Once that starts, and if the compressor doesn't cycle, the ice starts to build which in turn moves less air and the coils get even colder which in turn builds more ice.

Jack

Silvertwinkie · 06-24-2009, 06:47 PM

In a word, yes. These systems are designed to run. In some cases though you have to be careful of frost buildup, but typically I turn mine on and leave it on until it cools outside. On the newer units, the whole system cycles off, not just the compressor.

When it wears out, as they all do, get yerself a new one, but be comfy. Folks often times think they are wasting energy or cooling for no reason, but I would argue that letting the house or the RV heat up only takes longer to get to a comfy temp later. IMHO, spend the energy throughout the day or spend it running to get the space cooler it after being off for a period of time. Either way yer not gonna get a Greenpeace honorary membership.

leong1 · 06-25-2009, 03:02 PM

Thank you all for your replies.

Two more quick questions: If I leave the AC off during the day and the temp inside the trailer goes up to 110 or 120, will the high temp affect the operation of the fridge?

Also, Lumatic you said:

Quote:

"Now, if I'm not around I turn the thermostat down a bit."

When you say you turn the thermostat down, do you mean you turn it down to make the temperature colder inside? Why do you do this?

53flyingcloud · 06-25-2009, 06:01 PM

Quote:

Originally Posted by leong1

Thank you all for your replies.

Two more quick questions: If I leave the AC off during the day and the temp inside the trailer goes up to 110 or 120, will the high temp affect the operation of the fridge?

Also, Lumatic you said: When you say you turn the thermostat down, do you mean you turn it down to make the temperature colder inside? Why do you do this?

I keep a cheap fan, one I picked up from Wal Mart for under 10$, running all the time..plugged into 120v. Just point it skyward~! I find this keeps the frig working perfect..

Lumatic · 06-25-2009, 07:28 PM

By turning the thermostat down I meant set it to a higher temperature than the max. Also, I never tried J Canavera's idea above but I'm gonna.

leong1 · 06-29-2009, 11:58 AM

Thank you very much to all who replied to my question!!

Foiled Again · 06-29-2009, 01:40 PM

Isn't that much cooler than FL.

I set my "away" temperature at about 78F, when I'm home I set it at 72 or 73F. That way I'm not wasting the campground's electricity on cloudy and moderate days, and I'm not turning the inside of the A/S into a sauna either.

On a few vintage units I've seen what amounts to exterior window blinds - usually just a piece of fabric hooks on at the top of the window, and lays down to cover the pane. I have the SE Safari with the windows that fully open (like those on the classics and Internationals), so it wouldn't be a big deal to open the windows, catch the upper corners of a piece of foil bubble in each window and then let it lay down outside of the window for the day. Anything you do on the OUTSIDE of a window will be twice as effective as any interior blind, etc.

I suppose I could even make a "mini awning" by putting in a bottom dowel rod and making two little extender rods with suction cups on the end to hold the "mini awning" away from the window. For that matter if you have the Herr windows, get some suction cups with hooks and hook a cover over the window - suctioning onto the window at the four corners. It's always better to avoid overheating than to try to fix it once it starts.

Paula

Minnie's Mate · 06-29-2009, 03:56 PM

I agree with every one about taking more energy to cool a hot interior than to keep it cool all day long. You don't only have to cool the air inside the Airstream, you have to cool all the mass that is inside the Airstream. All the wood, aluminum, metal of other sorts, foam cushions, bedding, provisions, etc., all of which act as heat sinks and store the heat and radiate the heat back into the air as quickly as you cool it off. On a really hot day, you might not get the inside to a decently comfortable temperature until 11:00 or 12:00 at night. By then, it may be cooler outside than inside. Then you have been running the A/C for 4-5 hours and had to sit outside in the heat and humidity while the A/C ran without you waiting for it to get bearable inside.

Just turn the thermostat to a higher temperature so that the compressor will cycle on and off to prevent freezing up and invest in a surge guard or other protection device.