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lithnights

2 zone system in new construction..do it now or can do it later?

lithnights
10 years ago

I am having a 2 story colonial 3200 square foot house built in PA. The builder is putting in one 5 ton heatpump, with propane backup. My obvious fear is uneven temps between upstairs and downstairs, and after lots of great feedback from some of my other threads, I would like to do a zoned system.

They have already run ductwork for the 1st and 2nd floors (but have not installed the main plenum or return in basement). They are drywalling next week so I need to make a decision ASAP.

My problem is, the builder is quoting me an additional $3600 premium for a 2 zone system (Honeywell I think). We don't really have that kind of money but could do it next year or so. Furthermore, longterm I would love to have a 3 maybe 4 zone system, which would likely be even more. We'll hopefully be here 20+ years.

So..
1. I understand zoning involves the cost of 2 dampers, the extra and more complicated thermostats, some extra wiring, running 2 smaller plenums instead of 1 larger plenum etc., but an extra $3600? Is this really a realistic cost for this for a new install? Keep in mind the basement is entirely open, and the house is not drywalled, so we're not talking major work to run through walls like it would be as a retrofit. And the plenum nor return ductwork is installed yet. So is there really that much extra labor here to justify that price? Am I better off waiting until next year, when I can bring in a few reputable companies and at least try to get a couple different bids and ideas? Or could it possibly cost more to have someone come in next year to do it?

2. Assuming I could do it cheaper next year (by getting some competitive bids), I am leaning towards just having them run the wiring for future thermostats and anything else that can be done now, to get ready for a future install. Is there anything else they could/would run now that would make a future install easier/cheaper?

3. Based on my floorplan (attached) do you have any advice on zones? If I could afford 4, I'd love to do one for the left side of 1st floor, one for right side of 1st floor, one for master bedroom, and one for the left side of the 2nd floor for the other bedrooms. Thoughts? Should I expect to pay a much larger premium to get 3 or 4 zones? i.e. how much would it cost to go from 2 to 3 to 4 etc.?

I would appreciate any guidance on this major decision.

Thanks in advance!

Comments (7)

  • lithnights
    Original Author
    10 years ago

    Here is 2nd story floorplan

  • tigerdunes
    10 years ago

    This is just a repeat of your earlier thread from several weeks ago.

    Best advice is two systems.

    Next is zoning controls. Do it now, not later.

    The main cost of zoning controls is the control itself and ductwork design/sizing. Small zones are problematic. Cheap HVAC non var speed, single stage models can be problematic. Your dealer must have demonstrated experience in this area. Zoning is not for the faint of heart. You don't want to be an experiment.

    IMO

  • lithnights
    Original Author
    10 years ago

    Thanks Tigerdunes. Appreciate the feedback, but I didn't intend it be a repeat of my earlier thread. That was more of do I do zone or do I do 2 units? This is more of, "I now want to have zoning, but can't afford it now. Why would it cost more to do later, assuming this HVAC guy, and/or the builder, is overcharging me?" Know what I mean?

    So what I'm saying is, they have already sized out all the ducts and installed them. Essentially everything is done except running the main plenum and return, and hooking into the ducts leading into the basement.

    I understand the possibility of having them mess up zoning, but I've already called the York rep, as well as the Honeywell rep that deals with the HVAC company, and they both state that it's one of the best ones they deal with. So that gives me a at least a bit more of confidence.. I'm not dealing with a fly by night HVAC company.

    But my question stands, am I being overcharged at $3600, and if so, do I get competition next year and do it then?

    What exactly makes it so much harder then, than now?

  • tigerdunes
    10 years ago

    If you are going to do zoning, now is the time to do it. I don't like the idea of splitting the HVAC install and ductwork with one dealer and have another come in at a future date and add zoning controls. Plus there may be building obstacles that make it more difficult in the future plus compromises that could hurt the effectiveness of what you are trying to accomplish.

    IMO

  • mike_home
    10 years ago

    Unfortunately builders will overcharge for most upgrades. I would estimate the $3600 price is double what you should be paying given that the walls are open and the duct work has not been completed.

    I am not a zoning expert, but don't think it is realistic to create 3 or 4 zones with a single 5 ton condenser. I feel the zones would become too small and you will have air flow problems. That is my novice opinion, so I could be wrong.

    If you don't have the budget now, then your best course of action would be to see if you can create separate zones for the first and second floors. You have to determine where the dampers need to be installed so the two floors would be isolated. Those areas could be pre-wired as well as the wiring for the second floor thermostat. Depending on your layout this could very simple to very complicated.

    Have you thought about bringing in an HVAC contractor to advise you on what has to been done after you move in? You should take pictures of the duct work while the walls are still open.

  • lithnights
    Original Author
    10 years ago

    mike_home,
    The overcharging is my concern, that they are charging way too much, not only b/c the HVAC guy can (no competition) but also b/c the builder is then probably adding on 25% or whatever to the price, then charging me $3600.

    What you're saying about about manual dampers and running wire is exactly what I was thinking. I plan to discuss that with the HVAC guy. Although I'm sure he'll find a way to justify charging me an arm and leg just to do that!

    And yes, I have already brought in another HVAC company (good reputation, solid) for their opinion. He actually said he would do zone or just do a 2 ton upstairs and 2.5 or so downstairs. So there's always different opinions for the same situation..something I've learned throughout this process. Looking back, I should have brought in multiple guys a month ago, but didn't b/c builder had said months ago that they use 2 units for a house my size. But now I'm simply running out of time.

    No matter what I do, I plan to take hundreds of pictures before they drywall.. electric, hvac, plumbing, framing locations etc.

  • lithnights
    Original Author
    10 years ago

    After some long discussions with York reps and with Honeywell (who does the zoning equipment), I think (if the HVAC guy doesn't come down on price) I may have them run 2 trunks in the basement, and feed the appropriate ducts into each. i.e. have all the 1st floor ducts go into the trunk for the 1st floor and the 2nd floor ducts into the trunk for the 2nd floor. Then have them put in a manual damper near the beginning of each trunk, and have them run a thermostat wire upstairs for future use. I can't imagine this would be much more work than what they're planning on doing anyway. Remember the main plenum/trunk isn't even run yet.

    That way I can go the first year and see how bad the temp differential is between floors. And I could simply manually adjust the dampers each season (likely close off the 1st floor by a certain percentage) so that more or less air flow goes where I need it. If it doesn't work out, or if it does but my manual adjusting is too much work, I can do the zoning in the future without too much more cost, since the trunks are already done. I figure at that point, they'd just have to add the zoning panel, hook up the 2nd floor thermostat, add the auto dampers etc.

    And at that point, I could at least have some other HVAC guys come in and get some competition and different ideas.

    Thoughts on this approach?

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