I am replacing my central heat/air unit in a couple of weeks. The almost 30 year old one is dying fast (including the A/C ruining my floor with a rusted pan leak.)
My brother-in-law is bringing my unit. He has his own business and I'm getting it at cost. The problem...recent knee surgery will keep him out of the attic and I need to have the duct work ready when he gets here from Phoenix. The heat load is 60,000 BTU. Here are my questions.
1) Since I am adding a new unit I included the square footage in my game room. The previous owner was going to use this for a sun/spa room and for whatever reason didn't duct it.(it couldn't even be used in the total square footage when we bought it for that reason)
Problem---It is VERY narrow where this addition was added to the house. Both the opening and the narrowing at the edge of a gabled roof. I will need to get two vents in this room (about 400 square feet). Is there a special type of ducting for this? I opened the ceiling and the opening is 5 1/4" into the attic. No way a top mount register fitting will work. Ideas?
Do I need a return air line to this room since the doors are mostly closed because of noise? And if so, how do I get the return air line under the unit when I'm coming from the attic?
2) They also changed the garage into what is our master bedroom. It is cold in the winter and hot in the summer. Do you think I need to replace the ducts going to this room. It has flex duct right now. Or do you have another idea? This room is also about 40 to 50 feet from the return air vent.
I don't know how you're going to get a big enough duct to feed that 400 sq ft room through a 5" opening. Can you have the ceiling become a furr down meaning lower it so a duct can fit? Yes, return air would be good but not sure hoe you're going to accomplish that either.
As for your garage/master bedroom I'm betting it's an insulation issue that's contributing to the wide range in temperature, either no insulation in the walls or a few walls or not a good job done with it if it exists.