AC blower fan mod

[m0fugga]

My Airxcel 13500 ultra low profile AC in my Hummingbird only has lo and high fan settings. I've determined that allowing the blower fan to run while the AC compressor is cycled off is causing a drastic rise in humidity accompanied by mold growth at the supply vents. I'd like to possibly mod my AC to include something like an Auto/On toggle that will interrupt power to the blower motor if the AC compressor is not cycled on. Does anyone know of a way to accomplish this? As always, thanks in advance for any info you guys can provide.

[Rock]

You have low and high fan and fan auto and fan on. Fan auto will only allow fan to run with ac compressor on. Fan on let's fan run 24/7

[m0fugga]

Hey Rock, thanks for the reply! On my unit I only have the following four settings: Fan Low, Fan High, Low Cool, and High Cool. There is no auto setting. I called Airxcel the other day and they informed me that all of their units support the addition of an after market thermostat which would include an auto setting, so I'm going to inquire with my dealer on the installation costs for such a device.

[Studiovette]

If compatible with your rig I would go with this. I went from a manual t-sat to a digital one which is suppose to be much more accurate and hold temp within a degree or two.


https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[Jagiven]

A few years back a gentleman did this mod. He posted it here, and made a youtube video. As I recall it took two relays, and he wired it up and placed the unit in side the airstream. I believe he also added a wall thermastat.

[Rock]

mOfugga
It looks like they will do anything to save a penny, first one I seen with no auto. Mine looks just like one in amazon link.

[DaveT]

Install a PWM

Ebay

A diagram I found on the interweb



[Subaru297]

Originally Posted by m0fugga

Hey Rock, thanks for the reply! On my unit I only have the following four settings: Fan Low, Fan High, Low Cool, and High Cool. There is no auto setting. I called Airxcel the other day and they informed me that all of their units support the addition of an after market thermostat which would include an auto setting, so I'm going to inquire with my dealer on the installation costs for such a device.

My unit is the same as this and as far as I know the compressor is running all the time isn't it?
The AC is either on or off. There is no thermostat controlling it. I have never heard a change of tone indicating the compressor is cycling. Or is the compressor on a duty cycle related to the high or low setting?

Cheers

[Grumpy]

Originally Posted by Rock

mOfugga
It looks like they will do anything to save a penny, first one I seen with no auto. Mine looks just like one in amazon link.

His only has ceiling controls, no thermostat.

[01tundra]

Unit mounted controls only, no auto setting.

Select either high or low cool and fan runs continuous while compressor and condenser fan cycles on/off to maintain indoor temperature.

You could probably rig up a way to cycle the fan off, but I bet it causes short cycling on the compressor. The air temp will stratify up high at the unit if the indoor blower doesn't continue to run.

If there isn't any outdoor air introduced through the A/C unit then whether the indoor blower runs of doesn't won't have a bearing on humidity levels. I'm not sure if they are bringing in any ventilation air though our units.

[PonyExpress]

if your condensate water is not draining all the way, then when compressor cycles off you will start to evaporate the water back into the air and yes will feel humid.
I would also check that no outside air is not being sucked in.