Conversion of Window A/C to Portable Design?

[zpcm04]

Is there anything that would prevent me from constructing a ducted enclosure for a window unit, such that I could operate it inside the cooled space like a portable A/C?

BACKGROUND
I live in Jackson, Mississippi and have a workshop in an attached garage that I need to cool. The subdivision’s homeowners association prohibits the conventional installation of a window unit. I have considered portable units, but their cooling capacity will not be able to handle the heat load. Therefore, I am considering purchasing a larger window unit and building an enclosure that will allow me to operate it inside the shop without it being visible from the outside. The enclosure would be designed to draw in outside condenser cooling air and exhaust it outside, similar to the design of the portables. I would use an in-duct fan to overcome the losses due to the duct work and enclosure (the unit's condenser fan would remain functional).

Thanks

 

[marcoh]

By coincidence I saw a very similar installation last week and it seemed to work fine! Just need to match the new fan to the air quantity requirements of the AC.

 

[zpcm04]

Thanks for your response.

Do you recall:
- The size/configuration of the ductwork?
- The size/design of the fan?
- Was the fan mounted in the intake or exhaust duct?
- Did the fan have speed control?

 

[MintJulep]

Yeah, it'll work. But won't the association balk at the flex duct running out from under the garage door, or out the window?

I know it's way more expensive, but have you looked at ductless mini-splits?

 

[zpcm04]

Yes, I have considered mini-splits, but with a $1500 to $2000 installed cost, they break the bank.

I think I can hide the intake and exhaust from view. There are two fake windows (each 29" x 72") in the brick on one wall of the garage that are covered by vinyl shutters. Some of the neighbors have the bottom of the shutters kicked out 4 to 6 inches, like they do in the New Orleans French Quarter. I was thinking I could do the same and hide the duct inlet/outlet behind them.

 

[MikeHalloran]

I wonder if the neighbors have small air conditioners installed through the wall behind the kicked out shutters. If the shutters are louvered, they shouldn't seriously interfere with the hot air leaving the condenser. The typical a/c box sides only need to project six-ish inches outside the surrounding wall to take in ambient air to cool the condenser.

Mike Halloran
Pembroke Pines, FL, USA

 

[IRstuff]

However, the typical window A/C is pretty darn noisy. I doubt that you're going to be able to hide the noise much.

TTFN

Eng-Tips Policies FAQ731-376

 

[MikeHalloran]

On the inside is a workshop.
On the outside, the shutters might help a bit.

The inexpensive small Chinese- mode window air conditioners now on the market include multi- speed fans. Some controls include energy saving mode that switches to the slowest fan speed when near the setpoint. They're quiet enough for me.

The only flaw in the machine is that there is no budget for the electronic control, otherwise completely satisfactory, to store one binary digit of information: that the power switch was 'on' a second or two ago. So when our Deming- award winning power company supplies a brief absence of power, as it often does, you have to manually switch on the air conditioner. Units with mechanical controls are getting hard to find, and they're not energy efficient or automatically quiet, but at least they remember when they were 'on'.





Mike Halloran
Pembroke Pines, FL, USA

 

[marcoh]

Never looked lose enough to determine duct sizes, looked like a couple of 300 flex duct and a home made sheet metal adapter. Fan was on discharge side. Fan would only be small so using a cheap single phase speed controller would enable easy adjustment.