60 feet is not bad,all depends on what cfm is needed and the duct size.
Originally posted by classicrock4you
Gentlemen, I hate to sound like an ass (but I am so good at it, lol) but many of you need to re-read the post carefully and get your facts straight.
Rooms over the garage have 4 exposed sides, roof/ceilings,
unventilated kneewalls, etc. Heat gain per square foot is twice that of downstairs
This is not a garage, it is a a ROOM OVER an unconditioned GARAGE. Ductwork is in crawl, furnace in center of house (he said long run under house)The ROG now has a long run from the trunk, then, 90* turn, then up 16", another 90* turn, then over 15" and come thru ceiling. Talk about going around your elbow to get to your thumb, I bet the equivalent length on the supply line is 60+ feet.
NO RETURN mentioned.
Gentlemen, you can seal the ductwork with r-30 and it wont help this situation. You can install r-60 in the attic and it wont help. You can install a booster fan and it won't solve the problem. The ONLY professional way to solve the problem is to analyse the new situation, get out your tools (manual J and D), rip everything out, and start from scratch and do it the right way.