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  1. #1
    Join Date
    Jan 2005
    Location
    Bakersfield, CA
    Posts
    209
    New house is about a week away from HVAC rough in. Had planned on a 5 ton Trane XL19, XV90 3 zone system. The other option had been 2 separate systems. My contractor has been great until this week. It has taken several days to get a return call to set up a time for the rep to go onsite to plan the rough in.

    It appears that the original rep who was to handle the rough in planning has had an illness in the family and I am now going to deal with a new rep.

    I finally got a call from the substitute rep who will be planning my install. I asked him some final questions about zones, register locations, etc. and got some very perfunctory answers. I told him I had the Man J calculation and also a report that shows the loads for each zone. He had no interest (said "I determine loads by square feet and ceiling height"). The onsite foreman said the rep came by for about 10 minutes, discussed the attic access and marked the registers on the foundation and then left.

    I am concerned that all my time spent investigating and learning on this iste may be wasted if a poorly (or hastily) planned and executed installation goes ahead.

    At this point I plan on trying to speak to the owner Monday about my concerns, including asking for the details and support for the duct and register plan. If I can't get some good feeling that the install will be properly planned I am thinking about opting for the 2 system approach, thinking that might be easier to get right than a zoned system.

    Are my concerns legitimate, and can you suggest some questions I might pose to the owner on Monday?

    Thanks for your assistance.

  2. #2
    Join Date
    Mar 2003
    Location
    Cincinnati
    Posts
    7,977
    You're paying right ???? Tell his ass you want it done right or he can hit the road.

    If it's multi-story go with 2 systems.

  3. #3
    Join Date
    Sep 2002
    Posts
    4,970
    I guess Im currious , did he give you a bid price for installing the system with what was going in, As far as saying how many heat runs, how many returns venting and everything else with the option of a price for the two systems instead of the zones? Or is he doing it that you will just pay as to how you want it put in at this point from the way he originally planned to put it in. Did you talk about how you wanted it before he gave you a price? Thats just a few questions that I would like to hear before I give an opinion. mattm gave an answer that might just start a war and with that attitude of nit being diplomatic will make the construction of your house a living hell. Your better finding the facts before you burn the bridge.

    [Edited by dec on 08-27-2005 at 01:59 AM]

  4. #4
    Join Date
    Nov 2004
    Location
    SW FL
    Posts
    6,274

    Exclamation Plans & Specs

    Originally posted by nathan9999
    At this point I plan on trying to speak to the owner Monday about my concerns, including asking for the details and support for the duct and register plan. If I can't get some good feeling that the install will be properly planned I am thinking about opting for the 2 system approach, thinking that might be easier to get right than a zoned system.

    Are my concerns legitimate, and can you suggest some questions I might pose to the owner on Monday?
    What SPECS are included in your original contract?
    Did you approve and sign-off on these specs
    for a 3-zone system?

    Specs and drawings are a part of the bid.
    Stick to the _Plans and Specs_ or
    update them, then get revise bid(s) and re-sign contract.

    You MUST be Prepared to
    STOP WORK whenever needed until
    a clear, thorough understanding
    of plans and work progress are reached!

    Of course, builder will rightfully
    extend overall project schedule
    to address deviations and the resultant change orders.

    [Edited by dan sw fl on 08-27-2005 at 06:50 AM]
    Designer Dan
    It's Not Rocket Science, But It is SCIENCE with "Some Art". ___ ___ K EEP I T S IMPLE & S INCERE

    Define the Building Envelope and Perform a Detailed Load Calc: It's ALL About Windows and Make-up Air Requirements. Know Your Equipment Capabilities

  5. #5
    Join Date
    Jan 2005
    Location
    Bakersfield, CA
    Posts
    209
    Thanks for the responses. The bid was a one page description of the equipment used. It did not include detailed specifications of registers, duct layout, etc.

    The bid was basically type of equipment and a general description of vents installed, etc.

    What I was told was that the contractor would come out near the end of framing to settle on attic access and the site for the inside equipment, register placements, etc.

    I don't want a war, I just want a high performance system that is about twice the price of the builder's grade system (2 - Trane XB12, single stage 80% single speed furnace). A dual system was bid at various SEER levels. I chose the zoned system after a thorough consideration of the benefits and issues (and about 10 hours on this site).

    My concern is that this zoned system may be more dependent on a quality installation than a standard 2 system configuration.

    I accept responsibility for not getting the bid in a more detailed format. I think I was so happy to have found a contractor who would discuss a zoned system and who seemed to appreciate the value of a Manual J (about the only one out of 6 contractors contacted) that i didn't demand a more detailed bid agreement.

    Thanks again. I'm going to call contractor on Monday and express my concerns and see how it goes.

  6. #6
    Join Date
    Jan 2005
    Posts
    340
    Originally posted by nathan9999
    I told him I had the Man J calculation and also a report that shows the loads for each zone. He had no interest (said "I determine loads by square feet and ceiling height").
    Does your municipality require an energy use calculation (perhaps including a Manual J) as part of the permitting process? If so, maybe the building department would be interested to know the contractor's level of interest.

  7. #7
    Join Date
    Sep 2002
    Location
    South Dakota
    Posts
    6,579
    nathan, I see you are in Bakersfield, California. California's title 24 requires that a heating and cooling load calculation be done AND used when laying out and installing a system.

    You may want to remind your contractor that this is the law in Califorina plus you want the job done right.

    Correct duct sizing is determined by the room by room load calculation not by any rule of thumb. Using the calculated load for a particular room, the designer then calculates the correct CFM for that room. From there the designer calculates the correct duct size for that room. The duct mains are sized to the correct total CFM for all rooms at a specific system resistance.

    It sounds like the first guy from your contractor was on the right track and the second guy is going to go by experience and guesswork. California does not allow for that and neither should you.


  8. #8
    Join Date
    Jan 2005
    Posts
    340
    Great post, NormChris.

    For those who are interested, here's the specific requirements of Title 24.

    http://www.energy.ca.gov/title24/res...appendix_k.PDF

    The following steps should be followed in the design and installation of the HVAC system
    to ensure efficiency and comfort (for details, see section on Recommended Details for an
    HVAC System: Materials, Fabrication, Design, Installation, and Performance Testing):
    HVAC System Design and Installation August 2001 K-2

    1. Determine room-by-room loads and air-flows using ACCA Manual J calculation
    procedures (or substantially equivalent);

    2. Layout duct system on floor plan, accounting for the direction of joists, roof hips, firewalls,
    and other potential obstructions. Determine register locations and types, duct
    lengths, and connections required to produce layout given construction constraints;

    3. Size duct system according to ACCA Manual D calculation procedures (or
    substantially equivalent);

    4. Size HVAC equipment to sensible load using ACCA Manual S procedures (or
    substantially equivalent);

    5. Install equipment and ducts according to design specifications, using installation
    requirements and procedures from the Uniform Mechanical Code, the Air Diffusion
    Council, SMACNA, California Residential Energy Efficiency Standards, and
    manufacturers' specifications (Title 24); Using these procedures and those in
    Appendix A, the duct system should be substantially air tight;

    6. Charge the system appropriately, and verify charge with the evaporator superheat
    method or subcooling method (or substantially equivalent);

    7. Check for proper furnace burner operation and fire-box drafting;

    8. Test the system to ensure that it performs properly by determining (1) that the system
    is properly sized, (2) it does not leak substantially, and has either (3a) proper air
    handler fan flow, and proper plenum static pressures, or (3b) proper room and return
    air flows, and proper plenum static pressures. (Procedures are detailed in Section 3.)

  9. #9
    Join Date
    Jan 2005
    Location
    Bakersfield, CA
    Posts
    209
    Thanks for the very informative responses. I'll not bore you with the entire history of this process, but I can tell you that not one of the contractors I spoke with would meet the requirements of Title 24, at least in my opinion. Most were still using the "so many tons per square foot" method.

    I knew that sealed ducts were going to be required for permit pulled after 2005, but that's about it.

    The architect did include a Title 24 spec that called for 6.5 tons. The Manual J (which the Trane regional distributor technical advisor reviewed) indicated 4.5 tons. So I was a little skeptical of the Title 24 calc results (probably just an automated by-product of the program used by the architect). Having settled on the equipment I am now most concerned with the duct and register design and the quality of the installation, particularly because of the zoning issues.

    I will print out the Title 24 reference and provide it to my contractor. I must confess I'll do so with a little anxiety because I don't know if I can locate another dealer who will do any better.

    Thanks again for your involvment in a useful and informative forum.

  10. #10
    Join Date
    Jan 2005
    Location
    Bakersfield, CA
    Posts
    209
    Forgot to just ask a follow up question. What would be your reaction if a customer presented you with the 8 page document that Travis linked to?

    And as a recommendation for me, would you suggest that I present this to my contractor as the "desired" or the "mandatory" elements in my new system? Like I said, I don't want or need a war at this time.

    Thanks

  11. #11
    Join Date
    Sep 2002
    Location
    South Dakota
    Posts
    6,579
    I think the contractor is required to file a title 24 energy compliance form or set of forms with the state to show how your system is in compliance with the state regulations.

    Ask them for a copy of the filing. In addition, I think Pacific Gas and Electric Company maintains a title 24 energy auditor service to aid homeowners and contractors who seek assistance in these matters.

    All California HVAC contractors should be well aware of title 24. They are all required to adhere to it.




  12. #12
    Join Date
    May 2002
    Location
    Colorado
    Posts
    697
    Nathan,

    Have a lawyer send your contractor a copy of Title 24 along with a note about how you expect full compliance.

  13. #13
    Join Date
    Jan 2005
    Location
    Bakersfield, CA
    Posts
    209
    Panama, my concern with that approach is that at this stage I won't have a contractor. Our area is going full tilt on construction and all trades are hard to come by.

    I'm going to try the discussion approach first and hope we can come to an understanding.

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