Hello,

I've been trying to understand some of the mechanics of zoning. I've read a lot in this forum so I think know something about it now. But I have a couple of questions:

I asked my HVAC contractor about the variable speed and/or multi-speed blower option. I thought they would allow the system to run longer and be more efficient and dehumidfy more.

However, he says a single speed blower works fine and multi-/variable speeds are a waste of money. He says after the blower comes on in the variable unit, it will run slower at first but automically turn on to high speed after a few minutes if the desired zone temperature isn't reached pretty soon. It won't run at a slow speed for very long time even if just one small zone is on. It will go full blast after just a short time. So, "short cycling" still happens and is not really changed very much by using the more expensive equipment. And the super-dehumidifying claims are just advertising nonsense.

Is that so?

Also, I read about multi-position dampers being used in the supply duct and letting other zones be used as partial "dumps" to minimize inefficiencies and problems with bypass. He did not know anything about this and just used "full open" or "full closed" dampers. I had no answer to his question, "If you dump air into zones other than the one that wants the air, how do you stop the other zones from getting too hot or too cold?" I don't know. Any help?

//