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!

[ophiela]

We have on eceiling fan and have been considering getting two more for other reasons, this may just push us over the edge.

Well, they've installed today 4 dampers - 2 x 6" and 2 x 8"
and so far at least, it seems to be doing the trick. Suddenly both floors feel almost identical. They did say they might from time to time need to be manually adjusted, but only on extremely cold or hot days. Temps around here don't normally hit extremes, so maybe this will prove true.

After all the great insight from this board, we did get them to put in writing it would (a)solve the problem (b)not require constant adjustment (c)not effect efficiency

I greatly appreciate the input offered here.

GO HVAC guys (and gals)!

Ophelia

[fat eddy]

I guess I'm naive, I thought everyone put balance dampers in every run.

[rmeader45]

Originally posted by 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]

I think the key here is your builder said temp difference between "rooms" and not between floors of your house. Here in my area it is 8-10 degrees between floors with a system type that you have installed in a multi-level house. Sounds like a tract built house and not a custom house. As your well aware heat rises and with one t-stat and no zone you in the long run not gonna be completly happy. But then again ya bought a Ford house and not a Mercedes. Your actually lucky they installed the manuel dampers, but then again you ALREADY had that option with adjusting your original installed supply registers in each room.

[dash]

Originally posted by ophiela
We have on eceiling fan and have been considering getting two more for other reasons, this may just push us over the edge.

Well, they've installed today 4 dampers - 2 x 6" and 2 x 8"
and so far at least, it seems to be doing the trick. Suddenly both floors feel almost identical. They did say they might from time to time need to be manually adjusted, but only on extremely cold or hot days. Temps around here don't normally hit extremes, so maybe this will prove true.

After all the great insight from this board, we did get them to put in writing it would (a)solve the problem (b)not require constant adjustment (c)not effect efficiency

I greatly appreciate the input offered here.

GO HVAC guys (and gals)!

Ophelia

(a)Will most likely need seasonal adjustment,unless the upstairs was too cool in the summer.Hot air rises,cold air falls,winter-reduce air to 2nd floor,summer-increase air to 2nd floor.

(b)see (a)

(c)It has already changed the "static pressure" that the fan operates at,adding dampers will do that.This will add to the operating costs,maybe a little ,maybe a lot,can't tell from here.