I am new to the forum and whenever i have questions i try to come to forums where people may work in the industry since i don't.
So here's my problem...and it's one that is common and that is the cooling of a bonus over a garage. I have a bonus that we finished off a couple of years ago and contracted with a local hvac company to add a zone off of our current trane system. We looked at the possibility of doing a mini-split or adding a zone. Since my wife didn't like the looks of the mini split we prefered to add a zone if possible. One company came in and inspected the space and the current system and said it was large enough to handle the additional space so all we needed to do was add the zone and ductwork. We did that and have not been able to get the temp below 86 in the summer. I live in NC and we have many days in the mid 90's and low 100's in the summer and my house faces NW and we have a black roof.
The area in the bonus is around 350 sq ft runs off the upstairs unit which also cools two upstairs rooms that total around 450 sq ft. So right around 1000 sq ft and it's a trane 1.5 ton system. The company came out last year and replaced the flex vent running through the attic with rigid to get better flow but has not helped. We insulated well and i know bonus rooms are hard to keep cool when they have knee walls and are over a garage.
My question is, at this point they say they have done everything they can and it looks like we need a larger unit. Shouldn't they have known that when they did the analysis? That should have been in the original quote. With the cost of upgrading the unit, i may have gone with the mini-split. What should i expect from them? I don't want to be unreasonable but i'm not sure what they should be willing to do to make it right.
The current trane system is 4 years old so i hate to pull it out. I guess i could try to sell it on ebay or something.
Thanks for your help!