Page 3 of 4 FirstFirst 1234 LastLast
Results 27 to 39 of 45
  1. #27
    Join Date
    Sep 2006
    Posts
    1,253
    Quote Originally Posted by overhear View Post
    Thanks mchild, I'll take a look. I have the energy audit scheduled for next week. I'm hoping that will give us a better sense of what kind of tonnage we need and also serve as a reality check when bids come in.
    A well done energy audit will provide you with good information on how your home is using energy (Make sure the techs walk around with you and explain what they are finding and what you can/need to do about it. Don't let them just print out a report and leave it with you.) and will give you a much needed point of info for a properly run Manual J load calc which is the air infiltration. Once the audit is done you can decided what items you want to tackle on tightening up the structure. Air leakage is as much if not more of an issue as insulation. Insulation does not stop air flow. Air sealing is the only way to reduce air infiltration/exfiltration.

    Then you can have a pro (either HVAC contractor or engineer type) run a detailed room by room Man J. With this you can also do some what if runs to see the impact of making some of the improvements. It will help you decide where to spend dollars first. Don't be surprised if the home needs less heating and cooling than you initially thought.

  2. #28
    Join Date
    Jun 2011
    Posts
    20
    Quote Originally Posted by mchild View Post
    A well done energy audit will provide you with good information on how your home is using energy (Make sure the techs walk around with you and explain what they are finding and what you can/need to do about it. Don't let them just print out a report and leave it with you.) and will give you a much needed point of info for a properly run Manual J load calc which is the air infiltration. Once the audit is done you can decided what items you want to tackle on tightening up the structure. Air leakage is as much if not more of an issue as insulation. Insulation does not stop air flow. Air sealing is the only way to reduce air infiltration/exfiltration.

    Then you can have a pro (either HVAC contractor or engineer type) run a detailed room by room Man J. With this you can also do some what if runs to see the impact of making some of the improvements. It will help you decide where to spend dollars first. Don't be surprised if the home needs less heating and cooling than you initially thought.
    And it still makes sense to go forward with the audit now even though we will be replacing doors and adding windows during our renovation later? I can give the building plans to the tech performing the assessment, but want to be sure.

  3. #29
    Join Date
    Sep 2006
    Posts
    1,253
    Quote Originally Posted by overhear View Post
    And it still makes sense to go forward with the audit now even though we will be replacing doors and adding windows during our renovation later? I can give the building plans to the tech performing the assessment, but want to be sure.
    Some people do a before and after audit to confirm that the installers did a proper job and the window, as an example, don't leak like a sieve.

  4. #30
    Join Date
    Jun 2011
    Posts
    20

    Moving along, but still a bit stuck

    Hi All,

    I'm wondering if someone can offer me advice as I'm still floundering a bit here. After all the research I decided I definitely would prefer a multi-zone mini-split or VRV/VRF system with concealed (ducted) evaporator units. I thought I'd get 3 estimates -- 1 from the company that performed the NYS energy audit which does a lot of work in our area, and 2 other estimates ideally from companies that have experience installing split or VRV residential systems.

    But now I'm worried again. We are just a few weeks from putting out whole home renovation project out to bid and I'm not sure that I have a contractor with experience designing a DUCTED or concealed multi-zone split system.

    The estimator from the company that provided our energy audit said that Mitsubishi does not make concealed indoor units and after a while said that he had never heard of a VRV/VRF system. He will therefore only give an estimate for a packaged system. That was disappointing because I know this company will do a manual J and has engineering expertise.

    The 2nd contractor only installs multi-zone split systems but I don't think he's an engineering type as he hasn't taken any measurements. He is proposing a Samsung variable speed system for the 1st floor using units under the floor. A Mitsubishi multi-zone system would serve the 3 rooms and bath on the 2nd floor by tucking concealed ceiling units into the perimeter of the 3rd floor attic bedroom. He was not inclined to cool the bathrooms, but I asked for the design to have the 2nd floor bathrooms each share an indoor unit with the adjacent bedroom.

    He also gave me an estimate for a VRV system, but the price is 25% higher than the already pricey ducted split system, so I don't think we can go there.

    I guess I'm just not sure I've found the right person yet. I called the Daikin distributor and got the name of someone they sell to that installs lots of residential VRV systems. I'll try that person but meanwhile we are starting to lose time and I'm wondering if I should just give up and have whoever the GC on the job is just take care of it (sigh).

    Any thoughts?

  5. #31
    Join Date
    Sep 2006
    Posts
    1,253
    Quote Originally Posted by overhear View Post
    Hi All,

    I'm wondering if someone can offer me advice as I'm still floundering a bit here. After all the research I decided I definitely would prefer a multi-zone mini-split or VRV/VRF system with concealed (ducted) evaporator units. I thought I'd get 3 estimates -- 1 from the company that performed the NYS energy audit which does a lot of work in our area, and 2 other estimates ideally from companies that have experience installing split or VRV residential systems.

    But now I'm worried again. We are just a few weeks from putting out whole home renovation project out to bid and I'm not sure that I have a contractor with experience designing a DUCTED or concealed multi-zone split system.

    The estimator from the company that provided our energy audit said that Mitsubishi does not make concealed indoor units and after a while said that he had never heard of a VRV/VRF system. He will therefore only give an estimate for a packaged system. That was disappointing because I know this company will do a manual J and has engineering expertise.

    The 2nd contractor only installs multi-zone split systems but I don't think he's an engineering type as he hasn't taken any measurements. He is proposing a Samsung variable speed system for the 1st floor using units under the floor. A Mitsubishi multi-zone system would serve the 3 rooms and bath on the 2nd floor by tucking concealed ceiling units into the perimeter of the 3rd floor attic bedroom. He was not inclined to cool the bathrooms, but I asked for the design to have the 2nd floor bathrooms each share an indoor unit with the adjacent bedroom.

    He also gave me an estimate for a VRV system, but the price is 25% higher than the already pricey ducted split system, so I don't think we can go there.

    I guess I'm just not sure I've found the right person yet. I called the Daikin distributor and got the name of someone they sell to that installs lots of residential VRV systems. I'll try that person but meanwhile we are starting to lose time and I'm wondering if I should just give up and have whoever the GC on the job is just take care of it (sigh).

    Any thoughts?
    GCs normally know squat about HVAC so he will just turn to the low bidder (he probably already knows him) and tell him to slap something in. As in cheap.

    Each of the major Japanese manufacturers (watch out for the non-Japanese manufacturers) have contractors listed on their web sites. Also, as you have already done you can contact distributors too. VRV/VRF ssytems are somewhat idiot proof - but then again the installer really does need to know what he is doing to install it properly. Daikin is terrific in supporting their contractors.

    If you are concerned by having a quality Man J and duct design by Man D then hire your own engineer to do the work for you and then he can spec exactly what the system must do to be considered properly installed. There is a fair amount of work with all HVAC comfort system to get it rifgt so spend the time and money now and then you don't have to worry about having to redo it later.

  6. #32
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,756
    I can't see your project very well from where I'm sitting, but it sounds like there is some confusion about process.

    You need a design BEFORE going to bid, unless you like this gambling approach. Step back and think about this. You think the sales guy is going to spend hours and hours learning about a system, pay for custom engineering and design for your house for FREE, then stand behind that design, all in the hopes he'll get the low bid?

    If you want a design for a custom system that is outside the standard cookie cutter poke n hope work, you have to PAY for that design.

    Quote Originally Posted by mchild View Post
    If you are concerned by having a quality Man J and duct design by Man D then hire your own engineer to do the work for you and then he can spec exactly what the system must do to be considered properly installed. There is a fair amount of work with all HVAC comfort system to get it rifgt so spend the time and money now and then you don't have to worry about having to redo it later.
    Jumped me...
    What did the audit recommend? What did it say load was?
    Last edited by tedkidd; 08-07-2011 at 02:58 PM. Reason: Didn't see Mchild's good post
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  7. #33
    Join Date
    Jun 2011
    Posts
    20
    Thanks for the reality check, mchild.

    I'm not sure how to find an engineer to spec out the job. Since my architect, and presumably also the GC's he works with, doesn't have much experience with split and VRF systems, what's the best way to get a recommendation for a good engineer who has done that kind of work?

  8. #34
    Join Date
    Jun 2011
    Posts
    20
    You hit the nail on the head, tedkidd. I've been very confused about process. I totally get why a contractor wouldn't want to put the design work in upfront. And the fact that the architect doesn't think I need the system designed has been an added complication.

    Sorry but I'm a complete ignoramus and don't see anything about load in my NYS energy audit.

    I'm definitely ready to hire someone to design a system.

  9. #35
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,756
    Quote Originally Posted by overhear View Post
    You hit the nail on the head, tedkidd. I've been very confused about process. I totally get why a contractor wouldn't want to put the design work in upfront. And the fact that the architect doesn't think I need the system designed has been an added complication.

    Sorry but I'm a complete ignoramus and don't see anything about load in my NYS energy audit.

    I'm definitely ready to hire someone to design a system.
    The HPwES program and the TREAT software have a LOT of if/then, so none of us can claim to not be somewhat ignorant. That said, sounds like the ignoramus is your architect. Building houses that aren't comfortable to LIVE in misses the point of elegant design, doesn't it?

    The load calc is in the software, but probably not part of the report you received. Are you still engaged in conversations with the auditing contractor? Ask them what the base and improved loads were. TREAT comes pretty close to manual J. Both have a fair "safety factor."

    Did they come up with any hvac solutions?
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  10. #36
    Join Date
    Jun 2011
    Posts
    20
    The load calc is in the software, but probably not part of the report you received. Are you still engaged in conversations with the auditing contractor? Ask them what the base and improved loads were. TREAT comes pretty close to manual J. Both have a fair "safety factor."

    Did they come up with any hvac solutions?
    The guy that did the audit seemed great, but sort of deferred to his company's estimator. Then the estimator didn't seem to have ever seen a split system that didn't use a ductless evaporator.

    I'll call tomorrow and ask for the load info.

  11. #37
    Join Date
    Jul 2008
    Location
    Rochester NY
    Posts
    4,756
    Quote Originally Posted by overhear View Post
    the estimator didn't seem to have ever seen a split system that didn't use a ductless evaporator.
    I'm starting to get confused too. You want mini-splits, right?
    Which makes more sense to you?
    CONSERVATION - turning your thermostat back and being uncomfortable. Maybe saving 5-10%
    ENERGY EFFICIENCY - leaving your thermostat where everyone is comfortable. Saving 30-70%

    DO THE NUMBERS! Step on a HOMESCALE.
    What is comfort? Well, it AIN'T just TEMPERATURE!

    Energy Obese? An audit is the next step - go to BPI.org, or RESNET, and find an auditor near you.

  12. #38
    Join Date
    Aug 2011
    Posts
    568

    Cool

    Quote Originally Posted by tedkidd View Post
    I'm starting to get confused too. You want mini-splits, right?
    some of the fujitsue mini splits can use very limited duct work to do 2-3 rooms
    depending on btu's and room sizes. the operative word is limiited duct! some states and localites are even wanting ducted air from outside even with mini-splits!

  13. #39
    Join Date
    Jun 2011
    Posts
    20
    I'm starting to get confused too. You want mini-splits, right?
    I do have that effect on people.:-) I guess what I mean is the "concealed" ducted indoor units that Mitsubishi sells for their P-Series split system (for example, http://catalog.mitsubishipro.com/vie...oners-systems?).

    Maybe I am confused. Are those units really not very "concealed" when they're installed?

Page 3 of 4 FirstFirst 1234 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event