No answers Stinky - but we have a separate unit in our sunroom and also our garage (very large - 4 car+ and a workshop) and they work great. I don't remember the size of the unit (tons) for the garage. The one in the sunroom is installed in the wall below a window (it's not very tall) and has a programmable thermostat. We've never checked into the zoning thing, but our home is all one level.

Hope you get some answers!!

tina

Don't know if you have the space for more than one unit, but you might want to see about splitting the system into two, then you have a separate one for upstairs and one for downstairs. This is more efficient than a zoning. Might want to get a quote on that too.

I looked into converting our system into a zoned one and it was less than the quote you got and ours involved re-doing ducts and return air. We also don't have a variable speed fan and to add that the price comes close to what you were quoted, however yours already has that.

We are in a more semi-rural area and in TX. Sometimes things are less here and sometimes more.

Sorry I can't help you with the technical side but I can add my 2 cents about two zones. We have 2 zones - not upstairs, downstairs like you're considering but side by side because we have 2 separate systems. The original house is on one thermostat with it's own HVAC units and the 1000 square foot addition has it's own HVAC system.

One important consideration is that placement of the thermostats. You don't want to locate it in a room that is the coldest or hottest because then the temperature in that room will dictate the temperature for the entire zone. We had to move the thermostat because it was located in the room that had the most extreme changes in temperature in the summer and winter. When the thermostat kicked on in the winter to make that room comfortable all the other rooms were too hot and we had to play around with opening and closing the room registers.

Another factor is how your house is situated on the lot. Does one side get the full heat of the afternoon sun? Are there trees to provide shade in the summer? Is one side exposed to winter winds?

The builder put dual zones in my DH's business office which is only one story but one side was next to the paved parking lot and received the full effect of the summer sun. That side of his office was nearly unbearable in the summer even with awnings over the windows and Pella blinds inserted between the window panes. By making it dual zone they could compensate for the heat in that side of the office without freezing out the occupants in the other side.

It might be helpful to get another estimate - and another opinion.

As I mentioned I'm not knowledgeable of the technical side - exactly how does the automatic zoning work?

I just replaced my AC in our florida condo, 2800 squ feet, 5 ton Trane,
around 6,000. There was a Florida Power and Light rebate of 1,000, so
5,000$ My unit will also provide heating if needed ( rare in FL).

I think 2 zones is a good idea. We have 2 of everything though; so they truly run on their own; verses 1 system split in 2 zones. Our 1st floor unit had a $25 part go during the cold of winter; we were thankful that the bedrooms were upstairs in their own zone.

As far as thermostat placement; some times you just can't win. Ours is in the master; we'd like it in the hall but it's an open hallway; the last HVAC guy that came here told me that the unit would always be running because of the foyer. He did suggest adding another return on the other side of the house to help the air move better; so I'll be adding that.

Tina, thanks! I appreciate hearing about your sunroom and garage (which sounds huge!) Lucky you to have one story living!

Lyfia, that "truly" dual zone system IS the best way to go about it. It's efficient, effective, and wonderful, but it's also nearly double the expense! Don't know how long I'll be in this house, plus I have other substantial projects I need to budget for, including a huge master bath remodel. Thanks so much for your reply!

Maire Cate, thanks for your detailed response. All good points. I will review all the factors you have called to my attention. Good thing is my AC is still working, (though I'm sure it's relatively costly to run being 24 years old!) Still, I have time to gather info/estimates before I need the furnace to be working! I just found out that the furnace kicked the bucket when I had my AC cleaned and inspected this month. Didn't want to wait until the frost was on the pumpkins to research system replacement estimates/issues. Thanks again.

Mitch, that sounds great! What a deal. Maybe your price is so good because you don't have an actual furnace? We need a gas furnace and it is the most costly part of our system, by far. We'll get $500.00 back from the gas company, but will miss out on the Fed's $1500.00 rebate (from last year! Oh well.)

Hi Rose! Missed your reply. Thanks!

Sounds like you have an excellent system, much like the one Lyfia suggested. Guess there's no sngle answer or solution. There are so many variables that affect performance.

Stinky - we built our home - 13 years ago but still thought of our "advanced" years and steps. Our house is "L" shaped with the garage coming out the back. It IS a large garage but with 2 vehicles and a boat, and a hubby who loves to tinker, well that's his area. He also does some contract work from home, so it pays off. Our home is actually pretty compact, it's only the two of us. We have no hallways, rooms flow into each other. We were able to get what we needed on one level. We do have a basement but it is accessed only from a separate outside garage door. The sunroom started as a screened in porch but we loved it so much we wanted to be able to use it daily, so we sheetrocked, and had the sliding windows put in, so we get the best of both worlds. There is not a day goes by that we are not in that room.

tina

Stinky, I have radiant heat but I think zoning is wonderful. It is all attached to one boiler. We have 2 zones downstairs and then upstairs the childrens bedroom and bathroom are on one zone, the master bathroom has it's own zone and the master bedroom has its own zone.

The benefits we find are these: When we have an empty nest, we will not need to turn on the kids zone unless somebody is visiting. I like my room cold when I sleep so I never turn on the zone for the master bedroom. I like my bathroom toasty so that zone runs all the time in the winter. If I were to build this house again, I would have placed the children's bathroom on it's own zone or placed a switch on heater as that room tends to get pretty cool in the winter. We rarely turn on the heat downstairs because we use a woodstove so the separate zones are very important in that regard as well.

I have no thoughts on the worth for air-conditioning though as I stick with ceiling fans.

Unless you have rooms that are too hot or too cold with a one zone system, you probably don't need to go to the expense of a two zone. The manual zoning system would help push more cool air upstairs in the summer and seems worth installing for the price.

sg, another AC company quoted much more; you're right though, we don't have a separate gas furnace, just electric heat probably. If you need a dedicated furnace, this will bring the price up for sure.

First, Trane's are THE best IMO. Boy do they put out a lot of cold air!

I really can't help with your question but we have two systems now. One for the front part of the house since we built on, the other for the back part of the house.

It's been great turning the heat/air down when we're not using those rooms.

The price you quoted for the one system is the exact price we were quoted for a new Trane a couple of years ago here in OK!