Room Above Garage HVAC help

[Steve40th]

My room above the garage has two AC ducts allowing cool air to go in there. But, its always 10 degrees hotter in there. We keep the door open as it is upstairs and the house stays at 72, but that room just wont get cool, even with two ceiling fans.
So, the only option I see is a portable AC unit. But, do they need to be vented? Do they produce condensation?
The room has two windows on the roof that open to the elements, but no screens and they are sky light style.
I am trying to figure a way to cool that room as my daughter, her baby daddy and my grand baby sleep in there..
Any low cost solutions wood be great.

 

[ctgoodman]

That room is in a completely different zone and has a different HVAC requirement than the lower floor. From what you are describing you only have a thermostat downstairs and some ducts off of that system going into that room? Bottom line is it will never be equal or really even close in the extreme seasons. If it was me I would close off the ducts and install a mini split for that room. Then it will be comfortable up there. Also when you do this keep that door closed for the most part.

Also, how is that room insulated and is that adequate? Are the windows energy efficient?

 

[yeldogt]

You could try an internal duct fan -- I have actually been successful using one in a kitchen. But, I'm thinking 10 degrees is too much.

You would have to do a load calculation on the space and see what's needed (BTU's) to get the 10 degrees with a window type unit.

Or eliminate the ducts -- and go with a minisplit. How about one of the DIY units? with quick connect hose requiring no evacuation. ... sounds like this is a temp situation -- you don't need a 15 years solution. The DIY units are not the most efficient units -- but much better vs the efficiency of window units.

 

[Steve40th]

You could try an internal duct fan -- I have actually been successful using one in a kitchen. But, I'm thinking 10 degrees is too much.

You would have to do a load calculation on the space and see what's needed (BTU's) to get the 10 degrees with a window type unit.

Or eliminate the ducts -- and go with a minisplit. How about one of the DIY units? with quick connect hose requiring no evacuation. ... sounds like this is a temp situation -- you don't need a 15 years solution. The DIY units are not the most efficient units -- but much better vs the efficiency of window units.

The DIY units with quick connect hose requiring of no evacuation. Can you pm me one.. I have been searching..

 

[mopar4wd]

I used a duct fan for my daughters room seems to compensate up to a 3 degree differential but won't get to 10 degrees maybe a more powerful one would get closer.

 

[yeldogt]

Look up Mr. Cool (one brand) ... also we have a thread on them here ..if you can find it among all the mini split threads.

Or google DIY mini split ... they don't have many and they also have some that are not DIY within the same brand.. Have to look closely at the line set.

With the DIY one is stuck with the line set length -- obviously.

I'm thinking of doing one at my vacation cabin -- getting someone to the place is a pain and it's not like it's running 24/7 .. still would be 2-3x more efficient vs the noisy window unit.

The unit I saw had the line set already brazed/attached to the wall unit -- a connector fitting was installed on the outside unit. Attaching the line set to the unit -- broke the line set seal.

Some people have friends or other ways to get a normal one evacuated for little money -- if you can .... that may be a way to go.

If you go to third world countries these things are all over .. and they are not being evacuated ... many are using hose like found in an automobile .. with metal screw fittings.

Maybe the HVAC industry is keeping these out of the USA -- or some environmental laws.