Thermostat location problems...hot bedroom

arkaussie · 06-26-2007, 06:30 AM

This is our 2nd motor home and both have had the similar problem. Our bedroom gets too hot overnight. We have tried a small portable fan but it ends up in the way and gets knocked over etc. I do not want too run the a/c fan all night either.

I realise the problem is simply that the stat is in the center of the coach and does not "see" the bedroom heat build up over night.

Recently I had to change out my stat as it would not call for 2nd stage cooling and I got to thinking about installing a 2nd stat in the bedroom. To do this I would wire all the control wires together and just switch the 12volt to which ever stat I wanted to control the a/c. This would result in having the bedroom stat controlling the temp overnight and the original location taking control during the day when I switched the 12volt to the original stat.

I asked the people at RVP but they could not tell me if it would work. At $125 per stat I do not want to mess one up or my a/c control board for that matter.

Any thoughts??

arkaussie · 06-26-2007, 06:30 AM

This is our 2nd motor home and both have had the similar problem. Our bedroom gets too hot overnight. We have tried a small portable fan but it ends up in the way and gets knocked over etc. I do not want too run the a/c fan all night either.

I realise the problem is simply that the stat is in the center of the coach and does not "see" the bedroom heat build up over night.

Recently I had to change out my stat as it would not call for 2nd stage cooling and I got to thinking about installing a 2nd stat in the bedroom. To do this I would wire all the control wires together and just switch the 12volt to which ever stat I wanted to control the a/c. This would result in having the bedroom stat controlling the temp overnight and the original location taking control during the day when I switched the 12volt to the original stat.

I asked the people at RVP but they could not tell me if it would work. At $125 per stat I do not want to mess one up or my a/c control board for that matter.

Any thoughts??

Pubtym · 06-26-2007, 08:02 AM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by arkaussie:
This is our 2nd motor home and both have had the similar problem. Our bedroom gets too hot overnight. We have tried a small portable fan but it ends up in the way and gets knocked over etc. I do not want too run the a/c fan all night either.

I realise the problem is simply that the stat is in the center of the coach and does not "see" the bedroom heat build up over night.

Recently I had to change out my stat as it would not call for 2nd stage cooling and I got to thinking about installing a 2nd stat in the bedroom. To do this I would wire all the control wires together and just switch the 12volt to which ever stat I wanted to control the a/c. This would result in having the bedroom stat controlling the temp overnight and the original location taking control during the day when I switched the 12volt to the original stat.

I asked the people at RVP but they could not tell me if it would work. At $125 per stat I do not want to mess one up or my a/c control board for that matter.

Any thoughts?? </div></BLOCKQUOTE>

Check you over head vents and directions. Make sure cold air is not pointed directly or indirectly toward thermostat.

arkaussie · 06-26-2007, 09:31 AM

I believe you are missing the point or I just did not explain myself well. With 2 people sleeping in a small room for 6-8 hours there will be heat build up that the stat just will not see without circulation. The vents are not pointed to the stat and everything works just fine until we go to bed.

tomsm · 06-26-2007, 10:25 AM

Lindsay,

Since the outside temps are not sufficient to turn on the a/c, you probably would only need to activate one compressor. If that's the case, the simplest a/c thermostat from Home Depot or your favorite big box store might be all you need. You don't all the extra logic circuits and expense of the main thermostat. The new stat would probably only need 12v + & - , and compressor call line. Radio Shack probably has a switch that could switch all 3 of those lines at once.

The bad news is - I don't know enough to tell you whether or not you would risk damage to the main stat control board or the a/c control board. I just wanted to advance the idea that you probably don't need two $125 stats. Maybe one of our real electronic and air conditioning gurus will jump in here soon. Good luck...

tomsm · 06-26-2007, 10:49 AM

Oops - forgot you would also need a line for fan control...

TXiceman · 06-26-2007, 11:38 AM

Simplest solution is to just run the fan all night. At least it will stir up the air and keep the coach more even in temp.

Ken

arkaussie · 06-26-2007, 01:25 PM

Tom,
I have a spare stat that only calls for stage 1 cooling which would work just fine. I like your point that a standard stat could also be used.

Pusherman · 06-26-2007, 01:28 PM

Another possible (free) solution is to set the thermostat down at night about 5 degrees or so. The air between the front and back may stratify (warmer towards the rear vs. the front) but it has to somewhat equalize towards the middle of the coach where the stat is currently located. Worth a try, especially if no one is in the front of the coach (freezing away).

Petro · 06-26-2007, 01:55 PM

arkaussie;

We have the same problem especially when we close the privacy door. We run the fan on manual at night. That seems to help a lot.

Don

Pubtym · 06-26-2007, 04:57 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by arkaussie:
I believe you are missing the point or I just did not explain myself well. With 2 people sleeping in a small room for 6-8 hours there will be heat build up that the stat just will not see without circulation. The vents are not pointed to the stat and everything works just fine until we go to bed. </div></BLOCKQUOTE>

Just curious...what are you doing in that small room for 6-9 hours to generate that kind of heat? Guess winters are not a problem.

depchief · 06-26-2007, 05:08 PM

If you paraell the stats either/or will control the cooling/heat pump etc.

arkaussie · 06-26-2007, 06:14 PM

DP, If I could parallel the stat then that would be great but I think I would still do the 12volt select switch so I could select which stat is in control.

I don't like the fan blowing all night so was looking for a better solution.

ichn2go · 06-27-2007, 01:55 AM

The front of my coach is always different from the rear. A box fan (17.95) running on low on the dash when parked seems to equalize the temps.

But I know exactly what you mean about the heat in the bedroom. With a second thermo won't the rest of the coach be much cooler? Good Miles

John_Canfield · 06-27-2007, 03:09 AM

We have the same floorplan but don't have the same experience while sleeping. We set the thermostat at 75 degrees for bed time and usually that makes for good sleeping.

Thanks to an idea by Pat Tribby (while visiting on Pat & Diane's beautiful & immaculate Ultimate Advantage), I recently replaced all of the directional vents for a model that diffuses the air. This has greatly improved the distribution and mixing of cold (or warm) air. I'll be posting pictures and ordering info for the vents in case anybody else in interested.

arkaussie · 06-27-2007, 06:38 AM

Ichn,
The rest of the coach would be cooler but while we are sleeping it would not be a problem.

John,
The vents sound interesting but it would not help my problem as it is simply the stat not seeing the bedroom temp. I will check your site later to get more info.

fulltimer01 · 06-29-2007, 09:24 AM

John,
I would also be interested in seeing what those vents that diffuse the air look like.

Fultimer