Ducting Systems and Air Ventilation - HVAC - Single Zone to Multi-Zone - DIY?

We have a forced air system in our home that provides our heat in the winter and A/C in the summer. We have an air handler in the basement for the 1st floor and one in the attic for the 2nd floor. Each air handler has exactly one thermostat attached to it to control the temperature. I would like to create 2 zones on the 1st floor. How involved is this? Is this something I can do myself if I know the parts to get? Obviously I would need to install some sort of multi-zone board and cut into the duct work to install some mechanically or air controlled dampers to control the air flow to each zone. I may be able to speak with some experts at my local HVAC supply house but am not sure what information I would need to provide them so I can come up with a "how to".

Unit would have to have a VS blower. Some duct would have to be replaced. You will have to have a place to dump all the extra air with out freezing the coil. Id keep what you have!

Unit would have to have a VS blower. Some duct would have to be replaced. You will have to have a place to dump all the extra air with out freezing the coil. Id keep what you have!

Hmmm...that bad huh? What the heck is a "VS Blower"?

Variable speed! Not saying that it can't be done because it can. But zone systems have so many problems.

Zoning of residential forced air systems is usually a bad idea, sometimes a very bad idea.

I see. What are some of the issues? It sounds as though if they are single zone the air flow is setup to distribute the air evenly. However, we have areas on each floor in which they don't get as cool in the summer or as warm in the winter, even after fiddling with the manual dampers to each register. But then again, I don't want to throw the whole system out of whack either.

Hot and cold spots in a home is a duct design problem that can be fixed. Duct work will have to be sized for the heat load in each room. A heat load of the home will tell you this. This usally goes back to jack leg companys doing the install.

Hot and cold spots in a home is a duct design problem that can be fixed. Duct work will have to be sized for the heat load in each room. A heat load of the home will tell you this. This usally goes back to jack leg companys doing the install.

We have a billiard room that is located off of the end of the house (sits over the walkout portion of our unfinished basement) that has a catherdral ceiling. Double french pocket doors are the entrance to the room from our family room, double french doors with full size floor to ceiling sidelights to our outside deck, 2 double hung windows on the opposite wall, and the gable end has a complete unit of 4 double hung windows with fixed top lights above. A lot of glass in this room and it is tough to cool in the summer and tough to heat in the winter. What would you suggest we look at to get more airflow to the room?

If I remember right it has 5 supply registers in the floor (2 on each end of the french doors to the deck, 2 under each double hung window opposite and 1 in the center of the gable end) and one return in the floor just to the side of the french pocket doors to the family room. I think that the supply duct is 6" or 8" flex, I think 8" but I am at work and cannot say for certain. I know for certain it is insulated flex duct though.

Any help or insight would be greatly appreciated. Thanks!

Yes more air! Have a heat load done. This will tell you what you need to know to size the duct work.

Yes more air! Have a heat load done. This will tell you what you need to know to size the duct work.

Is the heat load something I could calculate or is it best to hire an expert? There appear to be numerous places on-line that can walk me through what I need to measure. Would I be looking for a heat load for just the room in question or do I need to do the entire house?

there are web sites that you can do a demo for like $50. If you do it right id do the hole home.