How to cool bonus room above 2-car garage?

[TITAN500]

We just purchased a new home (built in 2001) and we are having an issue with keeping a 13' x 22' bonus room above the gargage cool. You can actually feel the floor is warm due to the heat from the gargage "rising" through the floor (the garage has a ceiling...see photo...so I am not sure of the insulation). The bonus room has central air from the AC unit that is cooling the entire house but it is not able to keep that the bonus room cool. There is window in the bonus room above the garage but it faces the front of the house so I do not want to put a window unit in. Another option is putting a portable unit up there. We also thought about since we don't use the garage for parking cars (I have exercise equipment out there), would it help if we put a window unit in the garage which has a window facing the side of the house. Would keeping the garage cooler help with heat rising through the floor into the bonus room?

Thank you in advance for any suggests!

[BaldLoonie]

A 2 pipe portable unit, window unit in the space not garage, PTAC (motel unit) or mini split.

[TITAN500]

A 2 pipe portable unit, window unit in the space not garage, PTAC (motel unit) or mini split.

Thanks BaldLoonie! You will have to forgive my ignorance but what is a 2-pipe portable unit and what does mini split mean? I am considering this unit as a portable unit http://www.lowes.com/pd_211842-80003-PAC+C100EL_4294859075+4294931511_4294937087_?produ ctId=3305976&Ns=p_product_quantity_sold|0&pl=1&cur rentURL=%2Fpl_DeLonghi_4294859075%2B4294931511_429 4937087_%3FNs%3Dp_product_quantity_sold%7C0&facetI nfo=De'Longhi. Thoughts?

[heatingman]

It looks inexpensive enough to try. FYI you'll need to do something with the condensate (part of what an ac does is dehumidify). Also the unit may end up fighting itself b/c it looks like it will be rejecting heat into the same room you are trying to cool. Notice how your central unit has a unit outside to reject heat.

But if you have money, a better route would be a mini-split. Mittsubishi is one of the bigger names in the market.

A mini split ac is operationally similar to a conventional ac, but smaller and usually ductless. A mini split ac is also permanent.

[TITAN500]

It looks inexpensive enough to try. FYI you'll need to do something with the condensate (part of what an ac does is dehumidify). Also the unit may end up fighting itself b/c it looks like it will be rejecting heat into the same room you are trying to cool. Notice how your central unit has a unit outside to reject heat.

But if you have money, a better route would be a mini-split. Mittsubishi is one of the bigger names in the market.

A mini split ac is operationally similar to a conventional ac, but smaller and usually ductless. A mini split ac is also permanent.

Thanks heatingman! The unit I am looking at has a venting duct that mounts in the window like this: http://www.portableacguide.com/image...ernal-vent.jpg

[heatingman]

Well, I'd probably give it a try.

It would be proof of concept at the very least.

One thing to watch for is electric capacity of the outlet you plan to use. Air conditioners are typically a fairly large draw. I did not see any info about amp draw. It should have a dedicated circuit, so I strongly advise enlisting an electrician to evaluate the installation location for electrical capacity compatiblity.

[lentz]

A 2 pipe portable unit, window unit in the space not garage, PTAC (motel unit) or mini split.

A Mini-Split would work great. You have a remote stat. Can set it to come on and go off at about any time you would like.

[tipsrfine]

A Mini-Split would work great. You have a remote stat. Can set it to come on and go off at about any time you would like.

[Rcb2875]

You will be defeating the purpose while your floor is radiant heating the room. You would do best to spend the cash insulating the garage ceiling to isolate the heat there. OR insulate and cool the garage. You will have to decide which is more cost efficient, running a window unit to compensate the lack of insulation or tearing out sheetrock and insulating better.

[energy star]

Insulate the roof down to the floor. The knee wall is probably insulated not the roof to floor. If you have access doors for a storage in the knee wall seal them. Are the supply registers in the ceiling or knee wall. Get an insulated garage door.

[mchild]

TITAN500,

As others have noted these bonus rooms are often a problem. In many cases, the insulation is not properly installed for the room. The area behind the knee wall is attic space and as such will be quite hot in the summer. The wall between the knee wall and the room will often have no more than R13 when it needs more like R30 - R38 - like the ceiling of an attic.

The next issue is the insulation between the floor of the bonus room and the ceiling of the garage. Often this insulation is against the back side of the dry wall of the garage ceiling and not against the underside of the floor. There ends up being an air gap between the underside of the bonus room floor and the insulation. This air gap will normally be open to the area of the attic on the other side of the knee wall. Thus, hot attic air is moving through this space, heating the floor of the room and rendering the insulation useless. This can happen in the ceiling areas too with the insulation against the underside of the roof decking but leaving an air gap to the back side of the dry wall of the ceiling of the bonus room. Without resolving these issues the room will never be comfortable - summer or winter.

[jrpsimivalley]

all I got to say is fujitsu mini split heat pump

[tedkidd]

Thermal image camera diagnostics will visibly explain what mchild is talking about. Stack location, knee wall leakage, reverse stack, duct length, ac cycling, all add to "bogus room" problems.