Routing air from crawl space to outside condenser

[HotRodBoater]

I have a doublewide mobile home at the place I just bought down in the Houston area. I am about to have a slab poured and the mobile home moved onto it. I will be skirting from the home down to the slab and I had an idea. The outside condenser I have draws air thru the coils on the sides and out thru the top. I know that it's very important to have this area open to allow lots of airflow. This may be hard to explain without drawings...

What would happen if I "boxed" the sides of the unit in and "ducted" the box to the crawlspace and vented the crawlspace on the opposite far end?
My thought process: when the a/c kicks on it draws air from under the home doing 2 things. 1) putting cooler air thru the unit, cooling it faster and easier. 2) drawing fresh air into the crawlspace.

Things I'm not sure of: will this exchange of air make the crawlspace warmer or cooler? Will this **** the conditioned air thru the floors of a non efficient, poorly insulated living space?

 

[rlitman]

My thought is that the compressor fan is not designed to work with that much back-pressure, and so you'll cause big issues.

 

[Rockhead261]

The condensor fan is designed to operate in free air. Most manufacturers specify at least 18" from shrubs and 24" from walls. "Ducting" the unit will cause it to become absolutely filthy in a short time, and will probably entice rodents and reptiles into it.

Don't do it.

 

[matt_i]

I think messing with the airflow thru the condenser will lower its ability to transfer heat to the outside.

If you want to improve heat transfer, I would look at ways to mist the exterior of the coil, so that the fan inside will draw the moisture laden air thru the condenser.

The additional mass of the water plus possible phase change will extract additional heat from the closed loop to the atmosphere.

 

[Fixin'Stuff]

If you want to improve heat transfer, I would look at ways to mist the exterior of the coil, so that the fan inside will draw the moisture laden air thru the condenser.

Unless you do this with distilled water, I'm pretty sure that you would end up with a mineral encrusted coil before too long. Not exactly cost effective.

 

[rlitman]

Unless you do this with distilled water, I'm pretty sure that you would end up with a mineral encrusted coil before too long. Not exactly cost effective.

Correct. However, the condensate you spill from the evaporator side would work for this purpose.

 

[PWC Repair]

Unless you do this with distilled water, I'm pretty sure that you would end up with a mineral encrusted coil before too long. Not exactly cost effective.

Now there's a thought. Maybe run the condensate line over to the condenser with a tee and shutoff. During brutally hot weather you could drip the condensate right across the condenser by way of a 1/2" PVC pipe drilled with holes. Then switch the shutoff to drain normally during mild weather.

 

[HotRodBoater]

That's a pretty neat idea, I will probably play with that.

I just learned that the new way of doing things in the South is to no longer vent crawl spaces and attics, but to seal and insulate them and even have them slightly conditioned.

 

[TangoFoxTrot]

Assuming everything was working properly with it getting enough airflow, I still think whatever energy savings you'd realize would be minimal.

I would also think the air going through the condenser after a few seconds running through the ductwork would be the same temperature as the air that wasn't under the crawl space. It would just be pulling in outside air very quickly before the crawlspace could cool it.

It's not the craziest idea in the world, but if efficiency is a major concern, I would just buy a mini split and that's about as inexpensive as it gets. Like using a few incandescent lightbulbs and plug and play.

 

[LS6 Tommy]

All your going to gain is high head pressure. I'd leave it alone.

Tommy