Update: New project - forced air ventilation for the electrical bay

John_Canfield · 05-07-2008, 09:15 AM

Update: please see my last post...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We have seen our electrical bay temperature climb to over 120 degrees after a day on the road and running the inverter to power the fridge, Tivo, King Dome, etc. 120 degrees is right at the upper operating limit for our Xantrex RS2000 inverter/charger and I have been concerned about the long-term effect on the unit.

In fact, I just replaced the RS2000 unit (only a few months shy of the 36 mo warranty) due to the fans getting really noisy after it has been inverting all day. Don't know if the Alaska dust we accumulated or the high temperatures contributed to the fan problem but I needed to address the heat issue.

The project basically consisted of installing a 3" marine bilge blower underneath the bed blowing down into the electrical bay via a 3" hole I cut in the floor.

Complete project details and pictures here.

We haven't had a chance to test the blower under operating conditions, but we will be on the road later this month and we hope this will dramatically lower the bay temp.

If you don't know how hot your inverter compartment gets, think about buying a wireless thermometer and finding out!

John_Canfield · 05-07-2008, 09:15 AM

Update: please see my last post...
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We have seen our electrical bay temperature climb to over 120 degrees after a day on the road and running the inverter to power the fridge, Tivo, King Dome, etc. 120 degrees is right at the upper operating limit for our Xantrex RS2000 inverter/charger and I have been concerned about the long-term effect on the unit.

In fact, I just replaced the RS2000 unit (only a few months shy of the 36 mo warranty) due to the fans getting really noisy after it has been inverting all day. Don't know if the Alaska dust we accumulated or the high temperatures contributed to the fan problem but I needed to address the heat issue.

The project basically consisted of installing a 3" marine bilge blower underneath the bed blowing down into the electrical bay via a 3" hole I cut in the floor.

Complete project details and pictures here.

We haven't had a chance to test the blower under operating conditions, but we will be on the road later this month and we hope this will dramatically lower the bay temp.

If you don't know how hot your inverter compartment gets, think about buying a wireless thermometer and finding out!

codgerbill · 05-07-2008, 09:24 AM

hmmmmm...
Just a quick thought. If the problem exists only when driving or on the move why not just put a windscoop either on the door or underneath and have ingress and egress holes with louvers or some such things to cover the holes when not in use and maby a small filter to keep out dust?

John_Canfield · 05-07-2008, 10:08 AM

One of the project requirements was keeping water intrusion out of the bay while the coach is in motion.

My first thought was a vent (or two vents) located somewhere up high where there would be little chance for water to be forced in, but I couldn't be positive they would not allow water to penetrate.

This was not something I was willing to test since a design failure had disastrous consequences - damaging my $1,200 inverter.

Randy Chesnutt · 05-07-2008, 10:14 AM

On my Journey I had high heat in my ele. box after a long day on the road. What I found was that the muffler was reclose to the back of the boxs. I got a peace of sheet metal and put it between the muffler and the box,with a air space between the plate and the boxs. That help with the heat problem. I guess you can call it a heat shield.

SteveG · 05-07-2008, 12:47 PM

John, nice job and helpful explanation.

Can anyone recommend a remote temperature unit. The one I use for monitoring just the outside temperture uses two AA batteries in both the base and remote unit. I have to remove the batteries to preserve a reasonable battery life. I need to move on to a more sophicasted system with multiple remotes.

RCtime · 05-07-2008, 01:21 PM

Great job John and explanation.

How about a temperature contolled swich installed after the main on/off switch.
It would then run as needed. Just a thought.

John_Canfield · 05-07-2008, 01:25 PM

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SteveG:
John, nice job and helpful explanation.

Can anyone recommend a remote temperature unit. The one I use for monitoring just the outside temperture uses two AA batteries in both the base and remote unit. I have to remove the batteries to preserve a reasonable battery life. I need to move on to a more sophicasted system with multiple remotes. </div></BLOCKQUOTE>Steve - thanks

We use an Oregon Scientific wireless unit similar to this one. Ours doesn't have all of the features of this one, but it works pretty well. I think we got ours at Lowes three years ago. The batteries seem to have quite a long life-span - we only replace them once a year or so.

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by RCtime:
Great job John and explanation.

How about a temperature contolled swich installed after the main on/off switch.
It would then run as needed. Just a thought. </div></BLOCKQUOTE>Ron - that's a good idea and one that I hadn't considered. Once I get some operating experience with the current arrangement, I might do a thermostat - it would be fairly simple to wire. Probably the biggest hurdle is to find a suitable thermostat with an operating range of 100-150 degrees.

C Zimm · 05-07-2008, 06:01 PM

Aahh, John:
Something else for me to ponder. I run the "Demented" inverter a lot during travel and never considered excess heat. However, I don't have the fridge wired to the inverter but the in-motion TV or the I-Pod with the Bose speaker is usually on. At times the Micro-wave for a very short interval. Now if I can afford fuel to travel I'll need to monitor the electrical bay.

John_Canfield · 05-07-2008, 06:38 PM

Hi Cliff - ah fuel... we are cutting our summer traveling a little short this year due to the diesel prices and the market being in the tank.

We're heading to San Diego around the end of the month - I'll send you an email when we get in the area. (How about sending me your phone# in a PM)

I suspect if the inverter is basically idling, there isn't much heat being generated. Ours on the road is typically putting out 700-800 watts and generating lots of heat over several hours.

rv rick · 05-08-2008, 05:22 PM

John

Great project and pictures. I especially noted the 12v buss -- could you mention where on your coach that was located? I have a Tour that I suspect may be similar.

Thanks again for sharing.

John_Canfield · 05-08-2008, 07:13 PM

Rick - our 12 volt and 110 volt breakers are at the foot of our bed. On our coach, the bed was not designed with gas struts to where you can lift the bed up easily (although it was hinged to allow access to the workings underneath.

On one of our Forest City trips, we had the factory add the struts - now it is a simple matter to get to all of the previously inaccessible space.

Glad to share! You're welcome

rv rick · 05-09-2008, 05:04 AM

Our bed is the same -- a great idea that I shall adopt.

THanks!

John_Canfield · 06-23-2008, 06:45 AM

After about 2,000 miles of use, much of it in the hot South West, I feel confident in pronouncing the project a complete success.

In the worst case scenario, the electrical bay temperature was only three to five degrees hotter than the ambient air temperature - that was after pulling ~500 watts from the inverter for three to four hours.