Inverter/ Relay compartment cooling

[PapaBobby]

Has anyone noticed there is no external air vent for the compartment containing the inverter and relay assortment? This enclosure gets noticeably warm on a summer day when the inverter is operating, recycling the same air. Has anyone devised some type of external air supply or know of one available? Coach is a 2005 Open Road.

[alank]

Yes, I've noticed this, especially during the summer temperatures.
On my coach, the bay that encloses the inverter has some louver type holes cut in the front and back areas. I moved my inverter slightly to the rear of the compartment so I could easily build a shroud between the rear of the inverter and the rear wall where the louvers are cut. That way when the inverter fan comes on, the warm air is forced out the rear louver and cooler air is drawn in through the front louver.

[Argosy]

My original inverter was an older smallish Freedom with a 30 amp charger. It’s at the foot of the bed along with a couple of drawers that hang over the engine compartment. It does have a vent on each side of the bed base but they seemed to be for show. I upgraded batteries and the inverter, I now have a Magnum with a ~130 amp charger. It puts out a lot of heat for a lot of hours if the batteries are low with no real place for it to go.

Over the summer I got tired of hearing the cooling fan on the inverter screaming as it tried to cool with recycled hot air. I scrounged and found a snap disk and couple of small muffin fans that fit in the vent opening. The inverter exhausts out of the side, I made a bracket that holds the snap disk in the exhaust air and turns on the muffin fans. It worked well enough to keep the inverter fan from operating at top speed but still was warmer than I liked, I have a centrifugal fan ordered that has enough air flow to properly cool the compartment.

If you can make a couple of vents and draw some air through the compartment it very likely will extend the inverter’s life, heat is a big enemy of electronics.

[PapaBobby]

Thanks for all of the replies. I have replaced 2 inverters over the past 6 years. I took the last one apart and part of the circuit board was burned. I replaced the last inverter with one that had a larger capacity. Let’s see how long it lasts.

[dssl]

When I upgraded to a 3k hybrid inverter I installed a blower and some louvers. It's set up with a thermal switch that turns it on if the bay gets hot. I also installed a switch so that if the bay door is open the blower turns off since it's a bit noisy.

[PapaBobby]

Great idea. Where did you get the louvers?

[153stars]

The bilge fan moves a lot air. If it's a brushed motor a $10 pwm controller could be used to reduce the speed ,noise and energy used.
EDIT ....A quick look on Amazon to see if brushed motor. I see other people have used a PWM controller to quiet these down.

[Dutch Star Don]

My bays would get over 100 degrees in the summer. I used a 110-volt fan (pictured) as they are quieter than any high volume 12-volt fans.

I mounted it to the front wall of my pass-through bay, blowing out the wall of the bay into a dead area behind my fuel tank. In another bay, around the corner, I installed a vent with a hose that picks up cool air from down low at the rear of my fuel tank. Since it's 110 volts, I bought a 110-volt thermostat from Amazon that lets me set the temp I want it to come on.

[Argosy]

Originally Posted by PapaBobby

Great idea. Where did you get the louvers?

The louvers look like a dryer vent.

[dssl]

Originally Posted by PapaBobby

Great idea. Where did you get the louvers?

Yes sorry, yes it's a dryer vent. Smaller version the normal 3 inch vs 4 inch. Here is a link, no longer available from that seller.

https://www.amazon.com/gp/aw/d/B00AF...b_b_asin_title

I put a screen on the outside which was a bit of a kludge.

[dssl]

Originally Posted by 153stars

The bilge fan moves a lot air. If it's a brushed motor a $10 pwm controller could be used to reduce the speed ,noise and energy used.
EDIT ....A quick look on Amazon to see if brushed motor. I see other people have used a PWM controller to quiet these down.

The noise isn't really too bad, once I mounted it wit rubber mounts.. if everything else is quite you do hear it, that's why I installed the door switch to turn it off with the door opene. .the air path is a bit restricted so the more air moves the better, so I don't want to slow it down, but thsnks.

[dssl]

Originally Posted by 153stars

If it's a brushed motor.

A DC motor always has a comutator and a brush. Since it's a relatively cheap 12v motor it will be "brushed".

[153stars]

Tons of "DC fed" motors are brushless but they are not truly DC motors. Not every brushless DC motor will be happy running on a PWM speed controller on power wires. Some have seperate low power PWM speed control leads that might not be exposed. Most likely a basic brushless DC fan will work on PWM controller. I can find variable control for up to 4 computer fans that run by temp probe.Just not sure if target temp can be set for say 75-90f . Not going to spend any time on it if no interest OP seems happy with his nice setup at full speed.

Originally Posted by dssl

A DC motor always has a comutator and a brush. Since it's a relatively cheap 12v motor it will be "brushed".

[dssl]

Originally Posted by 153stars

Tons of "DC fed" motors are brushless but they are not truly DC motors. Not every brushless DC motor will be happy running on a PWM speed controller on power wires. Some have seperate low power PWM speed control leads that might not be exposed. Most likely a basic brushless DC fan will work on PWM controller. I can find variable control for up to 4 computer fans that run by temp probe.Just not sure if target temp can be set for say 75-90f . Not going to spend any time on it if no interest OP seems happy with his nice setup at full speed.

True, but a relatively inexpensive 12v blower will have a DC motor. Which is what mine is