Comfort Maker Model N8MPN100F20B2 balancing airflow split level

[demonrow]

Split-level house (upstairs above finished basement, main level above crawl which means short direct routes to the furnace) Problem: too much return on the main level, not enough upstairs. Upstairs is cool, but the main level is chilly and the basement is frigid.

When we had this unit installed in November, my installer suggested putting in one more return in the two back bedrooms upstairs. But suggested that before we spend the money, we try it out to see how uneven it actually is.

He also said that blocking the main level supply vents could freeze up the coil, that we should not close them down all the way.

So what's the best way to balance the airflow? Should I try blocking the returns on the level and basement? How? Magnetic covers? Have the kids sit in front of them? And the overhead vents in the basement may just need to be replaced - they basically don't close any more.

ANd one more thing: should we get that programmable thermostat? Opinions...?

Any inout / advice / tips / reprimands will be greatly appreciated.

Warm regards (ha ha ha ha ha ha ha ha)

D

[handy randy]

have you checked for dampers in the supply duct usualy near the furnace/air handler? try adding more air to warmer areas opening damper a little at a time and slightly closing off air to cooler rooms give each adjustment 24 hours before readjusting and yes never completely close any vents good luck and hope this helps 

[dkpd1581]

The best generic answer to your question is to install a zoning system.  For one unit to control so many zones with such diverse Heat/Cool requirements with one t-stat  located somewhere in the middle is asking too much from the system.

It is troublesome that your installer advised to "Wait" on a return and to "See how uneven it is."  That presupposes that he knew or suspected it to be uneven and was waiting to see if you could live with the degree of inadequacy.  A proper Manual J heat load calculation and Manual D duct design would have quickly zeroed in on the correct unit and duct design.  With that said, even the best circumstances would still make it very difficult to run essentially 3 floors and several zones per floor from one unit with one T-stat without a zone system.  Another better solution would have been more than one unit.  Your best solution is a proper assesment of your home's heat/cool needs which will lead you to proper duct layout.  These two will dictate the correct equipment.

Blocking supply grills and/or returns will in fact cause airflow issues that can cause freezing of evaporator coils, liquid damage to the compressor, water damage, and over firing in the heat mode.  I would suggest not doing that.  There are companies that specialize in airflow and balancing, you may try having them come out and give an assesment.

As to programable t-stats, they are a great thing if you actually leverage their capabilites, schedule them correctly, and leave them alone to do their job.  Many times people put them up and fiddle with them just as if it was a manual mercury bulb t-stat - overriding the program all the time.  Often times people, not understanding how to program them, end up getting frustrated with them and having all types of mismatched programs in them, wrong day, wrong time, and the unit may not work correctly or provide the savings and degree of comfort expected.  The answer to your question lies in your end goal to be achieved, your living patterns, and usage of the house/spaces within.

I relate it to people who have the newest/best electronic equipment with all bells and whistles.  They show it to you and explain how wonderful it is and there you notice that the time is perpetually flashing 12:00 on the face of it.

Your case is one that has soo many variable that it is best to have an eyes on assesment in my opinion.  Best of luck.

[demonrow]

Thanks Randy & DK,

No dampers in the supply ducts, and DK, a lot of the duct work is now in the finished ceiling of the basement. I think maybe my guy thought that the new system would heat/cool more efficiently, and that's why the suggested wait. I'm guessing. He did say he'd put in the extra return for cheap if we decided to go that way. I agree that it sounds like an eyes on job. And I won't go closing off any vents in the meantime.

Thanks for the input,

D