Two Zone HVAC - Brook Hollow

Looking for some guidance on updating our hvac system. We currently have one zone (1st floor), and are considering adding a second zone.

Does anyone have recommendations on companies that do this type of work? Secondly, is their anyone in Brook Hollow who has gone through this that could shed some light on the complexity of the project?

Thanks in advance!


I haven't a clue how complex it is, but I will give props to Harmony Heating. They were the only ones to be able to do a very complex install in our home (central A/C in a 3-story 250yo house). If it turns out to be difficult, you may way to call them. Also their team is great - always polite and on time.


Before you go too far, ask your self what is the reason for two zone? What problem are you trying to solve? If it's something like an area that's always too hot or cold it might be something as simple as duct work. Or the solution is a simple upgrade in the fan. If just a small area, then can you get by with cheaper supplemental heat/AC. Get a couple of good companies to come in and discuss what the problem is and go over solutions you'll be happy with.

For companies - search the forum for "HVAC". HL is littered with them, only a few names keep coming up over and over. In my case I only needed a replacement unit, no additional units or changes in zones. I got estimates from Air Group, TGM, and All Temp. Air Group had a really nice Carrier unit but even though I love their service, the price differential was just way too much and I went with TGM. Did a great, neat, well planned out job.

One thing you're going to come across is the duct work near the unit has to be changed. The code for the exhaust side has changed since when our homes were constructed . That takes with it a change in pipe size because of the water heater that's also there. Plus they generally need an outlet for an inside pump (luckily the sump is right there), and an outside electric outlet. If you get any work done, go over all of the ancillary items. Particularly when you're talking the additional zone.


Three floors, 250 years old, wow. Like 1776, wow, that's tough to do out here in the hinterlands. Three floors, that's hard to do all around. Have old house too, but only 150 so we sort get two zones by definition, basically two units.

2nd floor ducts come down from attic, air handler in attic, compressor outside. Only difficulty was finding raceway to link compressor to handler which is pretty small rqmt. Otherwise, they put a vertical gutter on the side of house to use as raceway.

1st floor ducts come from basement, air handler in basement, compressor outside.

So basically two units which if size works, didn't cost that much more that a single unit able to handle multiple zones. Also basically have 50% service if one unit fails.

I am kind of overbuilt so can cool very quickly but also can maintain often with only the upstairs unit on. Could have used a single unit but the ducting and system cost didn't outweigh having the redundancy and power of two units.

I would agree though, it depends on size, etc. and you may want to look at those ductless units which don't require a window and put out some pretty good numbers of cooling.

strangerdanger strangerdanger
August 12th

I did my system 3 years ago in that area. I didn't go with 2 zones, would have been more costly and unnecessary. The HVAC people noticed that the builders ran a return in our finished basement that was handling more air than the return on the main level. So in summer months it would take a long time to cool because it was drawing cooler air in from the basement. Anyway we closed that off and with the newer equipment house feels great at 74/75 on the hottest days, any lower it my wife complains. It's still 5 degrees warmer upstairs but with the variable speed blower and upstairs sensor (allows the system to monitor temps in dual locations) it works out well. Oh, and with the new equip. Electric bill $58 Gas bill $47, budget amounts of course. But usually left with a credit at the end of each year cycle. Couldn't be happier really.


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