I own a two story home near Chicago in Illinois and my 60+ year old home has had heating and cooling problems since I bought it. I have a forced air system (3 year old furnace) that has one main feed into the house that spilts and the spilts - split to feed into the individual rooms. I get poor air circulation on the 2nd floor where the bedrooms and bath are and not so good heating and cooling on the main floor. I have had 2 different HVAC reps. out to look things over and both stated that the existing duct work is the source of my probelms AND my central air unit (2 tons) is too small for my home (approximately 2000 sq feet). Both persons offered their opinion that I have the duct work rerouted. Is that possible and if so could it solve my problems?

If the A/C unit is too small, nothing you can do with the ductwork will help matters at all. A thousand square feet per ton is definitely asking a lot,

Where is your unit located? If it's in the basement, consider cutting off the second floor ductwork, and use the unit for the first floor only. Then install a second unit for the second floor, with ducts in the attic. If the unit is in the attic, then it would be vice-versa.

Thanks for the response. The unit is in the basement and the duct work going up has a long run across the basement before it splits and goes up. I think monkeys installed this - no wait they would have been more thoughtful before running this mess. Now, I asked an HVAC person about getting a 3 or 4 ton unit (knowing the 2 ton is too small) and he is under the impression that the "A" coil would freeze and become a problem because the cold air wouldn't be able to move through the duct work fast enough. I also though about cutting off the second floor, but then I have the issue of heating 4 fairly large rooms during a Chicago winter. Can duct work be rerouted without cutting open every wall on the main floor?

Nothing you can do with the ductwork will make up for two tons of absent capacity. There is no reason a second unit in the attic serving the second floor only could not also have a heating coil in it. What is the source of your heat now? The same source could be used in the attic. It seems like the simplest way to do it, and you'll end up with two zones, a distinct advantage.

Thank you for the response. I agree with you and think that will be the best way to go (2 Zones).

Having your ductwork system replaced/rerouted will solve the majority of your air flow problems of your home and help improve the air conditioner (improve, not solve). Adding a second system in the attic could aleviate these problems as well but then you'll have two separate systems to maintain/repair in the future (plus a large investment).

A better solution would be to have your current ductwork system replaced and add on a zone control system. This still provides you will multiple zones independently controlled from each other (increases comfort, utility savings and adds capacity to your air conditioner). This also keeps you with a single heating and air conditioning system to take care of.

Also, since your furnace is fairly new it should be sized for your entire home (not just the first floor). If you block off the second floor ductwork from your furnace it will cause your home to be more un-evenly heated (we call it short cycling of equipment). This causes your home to have greater temperature swings which decreases the overall comfort of your home (feels drafty).

Hope this second opinion helps - GWC