Regulating Air Temperature in Bi-Level Home

[ophiela]

I own a two-story home with one HVAC unit ("Goodwin" or "Goodman", I think). There's one thermostat - it's not zoned.
When the outside temp is 75, and the tstat is set to 74, downstairs temps fluctuate from 71 to 78, while upstairs temps fluctuate from 80-89 degrees.
I recently spoke with a HVAC company who recommended a zoned system. It's a relatively new home and the HVAC system is actually still under builder's warranty, which is soon to expire. (Warranty states temps shouldn't fluctuate more than 5-6 degrees between rooms.)

Now the same company (the one the builder contracts for the warranty work) is telling me they can install more dampers to regulate the air, but I'm concerned the builder is just trying to get out of the expense and buy time until after the warranty expires. I know the builder doesn't want to go to the extra expense of installing a zoned system, and I don't want to get stuck with the expense myself.

Can anyone tell me what the likelihood is that more dampers will actually regulate the system/temps properly?
If dampers will get the job done, that's fine.

Thanks.

[Edited by ophiela on 02-24-2005 at 04:35 PM]

[billva]

i love your signature line, although i would substitute something else for the chocolate, like maybe another martini.

you have a common problem, i'm guessing this is a townhouse.

by installing dampers you will force more air to the desired level, in cooling upstairs, heating down.

this will help somewhat but can, and probably will reduce the efficiency of the system.

if you start the solution now with the builder, he may have to keep the warranty going until the 5-6 degree temp. difference is achieved. (but probably not, and you wont know that until the hottest or coldest days of the year)

zoning will require alot more expense to him, it WILL be his last resort.

sorry to hear about the goodwin.

good luck

[dash]

IF the duct system is properly sized(unlikely),AND the dampers can be located in and easily accessable place,you will still need to adjust them for the seasons.

When they damper off the second floor for the winter,it will not have enough air for the summer,so it will be too warm.Thus they will need to be reset,for cooling.

The builder paying for a zoned system,is very unlikely to happen,but you never know.

With properly designed ducts and a good zoning system,it'll work perfactly,not always easy to be sure this happens.

[pipedope]

Dampers will help! There is no way the builder will pay for Zoning! Try setting your fan on the thermostat from auto to on will keep air circulating and decrease the temp swing between the two levels.

[billva]

are there returns on each level?

[thermister]

I agree with pipedope plus it will keep the house air cleaner and fresher. Dampers will help but, if the ducts were not sized properly and supply and return ducts are not positioned properly the builder should be held responsible and it will roll down hill from there. Be sure you document everything you do, all your interaction with the builder/contractor etc. Get the ball rolling before you are out of warranty.

[ophiela]

This is basically what I suspected - though I know as much about my HVAC system as I do about quantum mechanics.
I greatly appreciate the unbiased feedback and understand the challenge I face with the builder.

Uhm - dumb question - is a register = return? There are three returns - one below the thermostat, one in the hallway right at the top of the stairs, and one just inside a bedroom door just at the top of the stairs.
Logically, the two returns would be pulling all that hot air (which tends to rise anyway) right up the stairs, I suppose...

[ophiela]

pipedope - if I set my fan from auto to on, won't it run continuously and hike up my bill? Or am I missing some piece of logic here?

[pipedope]

yes and no. the blower does use energy which will increase your electric bill but if by circulaing the air may reduce the run time of the furnace or in the summer the compressor. which saves you money. also if the house is at a more constant temp you may be able to lower the thermostat setting to accomplish the same level of comfort.

[ophiela]

pipedope - Maybe I'm not understanding - do you mean that just because the fan is on, the compressor/furnace aren't necessarily cooling/heating and that use of those is still regulated by the tstat? If so, I didn't realize this.

[tinner73]

"on" from the stat makes the blower from the furnace/airhandler run constantly. heat or a/c will still come on as needed, but the blower will not shut off. it is just a big circulation of all the air in the house.

[tinner73]

"auto" from the stat has the blower come on with the heat or a/c. after the stat is satisfied, the blower shuts down. sounds like you need more air movement. do you have ceiling fans?

[cem-bsee]

in a well designed system, the temp should be +/- 3F between rooms just after the blower shuts off (not in auto)

ask if anyone did a load study to determine the actual needs of each room?
same problem in both heating & cooling season?
got shade on west? film on west windows?

return air grills are normally larger & not closeable, on inside walls

re: elec use of blower: try it one month -- BUT you need to track DegreeDays vs kwh usage AND know your base elec usage when heat & cooling need is none or small, usually in May or Oct -- else you will NEVER be able to determine the influence of the blower -- may cost extra $3- 5/ mo to run continuous --

be aware, having the blower run all the time does not allow the a/c remove humidity as well!