HVAC Residential Question

[Pete Pemberton]

1st post, hopefully I can contribute some in the future.

2nd story gets too hot, need to increase airflow to upstairs, or draw of return. Professional suggested increasing size of rectangular run off plenum from 12x8 to 16x8. Cap off and reroute one run to upstairs directly out of plenum. $500 quote, run is abot 16' and price includes cap and 3 larger takeoffs for added air pickup.

No air flow technical tests were conducted to measure draw or load of system. (just repeating what I have read in other threads, I have no knowledge of what tests are available, etc.)

Carrier 3 ton system, no attic fan, 10 SEER (more than likely). Yesterday outside temp was above 85, thermo set to 75 ran all day after servicing and recharging in mid AM. Inside temp went from 81-75 in about 6-8 hours.

House is 2 story, 4 bedroom upstairs, return in each bedroom, and one small and one large return on 1st floor. rough sqft is 3600.

Also, A coil has a leak, he quoted two models with installation and drier compound (in case moisture was drawn in during recent freeze over of coils) $900.

All comments and suggestions are welsome, well, except flames...

[c_kubie]

May want to vent the Attic. A sealed attic with no air flow isn't good.

Also, my want to post what state you are in? $500 for seems reasonable, but it also deplends on what kind of access does he have to the ducts.

[JimL]

Just about everyone in my neighborhood has added a second system and dedicated it entirely to the upstairs. They are extremely pleased with the results.

Of course all the new 2 story homes are now being built with 2 systems.

[Pete Pemberton]

Upper middle class suburbs north of Cincinnati, OH. 9' exposed ceilings. There is nothing in the way. He claimed alot of labor to take down the old and redo the new, or whatever he is doing...

[tbasc]

I'd check the local climate before venting the attic. However, the pooint is a good one.There are a lot of things beside mechanical systems that affect heat.

The Building Science Corporation web site would be a good place to start.

TB

[tbasc]

What is an "exposed ceiling"? TB

[Pete Pemberton]

Unfinished?

[Travis Jordan]

Install a second system for the upstairs, and downsize (replacing) the existing first floor system. Have the bidding contractors include a "Manual J" heat gain calculation as part of their quotation process. Base your new systems on the results of the Manual J's, but DO NOT OVERSIZE. Only consider variable speed air handlers - better humidity removal, cheaper to operate, and very quiet in low-speed modes.

In an upper middle class home, I'll bet this is the only way you're going to be happy in the long run.

[ds549]

a freind has a 27 year old brick 1100sq ft with central ac house that was hot when 90 and above. it had plenty of eave vents but none on the roof. we put a power vent for 1600 sq ft on the roof in the center of the house and that really cooled that house down. the house also had enough insulation ,trple pane windows and damn good doors.and ac is adequate. it sits out in the sun in central ky. lucas