Page 2 of 2 FirstFirst 12
Results 14 to 19 of 19
  1. #14
    Join Date
    Jul 2006
    Location
    NW burbs of Detroit
    Posts
    6,058
    Quote Originally Posted by mtamara View Post
    I have the same situation as the original poster, and want to do the work myself. No one returns my calls when I mention that the ducts are in a crawl space.

    1) Would metal tape be as effective as mastic for sealing the ducts?

    2) What kind of insulation works best, esp for a DIYer? Fiberglass? Reflectix?
    Advice...OK . DIY...NO WAY!

    Please read the rules for posting.

  2. #15
    Join Date
    Jun 2001
    Location
    Louisville, KY
    Posts
    12,189
    Quote Originally Posted by skippedover View Post
    Air moves through insulation and for the non-believer, just know that air FILTERS are made from the same material as the most popular insulation, fiberglass. So the real answer is first to thoroughly seal the ducts to stop air from going into or out of the ducts anywhere except within the treated space. Once you've got the ducts completely and thoroughly sealed (not with duct tape) then you can insulate to great advantage. Don't be fooled either. The high velocity systems are no more leak proof than any other using flex duct if they're not installed properly. Furthermore, the high velocity systems start out with a lower SEER rating and so are not as energy efficient to begin with. So even if their ducts were more leak proof, the trade off is in loss of efficiency up front to loss of efficiency through the ducts. The HV systems do have a place in life, somewhere but ease of installation (meaning higher profits) is the reason some contractors install those systems. Other companies sell their systems at a high enough profit margin that they can install very high efficiency, super quiet, systems with thoroughly sealed ducts.
    How much insulation do you recommend?
    Perhaps you should have read the instructions before calling.

  3. #16
    Join Date
    Dec 2007
    Posts
    26
    You are correct on load design and Espi Tech offers this service both on line and in house. a real advantage however is the exact cftm is given for each run, so, IF, the contractor does the proper calculations the exact number of outlets per room are known.

    I would imagine less than 5% of contractors really do proper load analysis. I have talked to many so called pros that oversize product to a great degree to cover thy butts.

    That being said plumbers are looking for other ways to make it due to the DIY crowd and the Home Depot mentality. I mean really, Trane is selling in Home Depot and that in my mind no matter how it is done strikes all in the industry in the wrong way. It will not take long for similar retailers to buy a private label from desperate mfg. hire their own installers and bam, everyone is out. If we were all smart would stop buying Honeywell and anything sold directly or some how indirectly from our industry to the home owner direct. Plumbers will tell you it is a slippery slope indeed.

  4. #17
    Join Date
    Dec 2007
    Location
    Denver, CO
    Posts
    1

    Hi-Velocity

    I am quite familiar with the Unico System (high-velocity, small-duct) and they offer both free load calculation and duct design services. Of course, their designs won't work for conventional systems, so only utilize if you are considering high velocity or it will just be a waste of your time and theirs.

    Also, Unico's high velocity systems are rated different than conventional systems. Due to the difference in engineering, tradional SEER testing does not properly rate Hi-Velocity, Small-Duct systems and the Department of Energy has a different rating technique for high velocity. That rating document can be obtained from Dept of Energy or Unico's marketing department.

    So the statement "Furthermore, the high velocity systems start out with a lower SEER rating and so are not as energy efficient to begin with" is misleading if you do not get all the information available and understand the different engineering aspects of conventional vs high velocity..

  5. #18
    Join Date
    Dec 2007
    Posts
    26
    Quote Originally Posted by Load-Calcs View Post
    I am quite familiar with the Unico System (high-velocity, small-duct) and they offer both free load calculation and duct design services. Of course, their designs won't work for conventional systems, so only utilize if you are considering high velocity or it will just be a waste of your time and theirs.

    Also, Unico's high velocity systems are rated different than conventional systems. Due to the difference in engineering, tradional SEER testing does not properly rate Hi-Velocity, Small-Duct systems and the Department of Energy has a different rating technique for high velocity. That rating document can be obtained from Dept of Energy or Unico's marketing department.

    So the statement "Furthermore, the high velocity systems start out with a lower SEER rating and so are not as energy efficient to begin with" is misleading if you do not get all the information available and understand the different engineering aspects of conventional vs high velocity..
    As I understand it Unico got away with the old design of the system and only 200 cfm/ton by claiming the lack of leakage, and really in my opinion a cop out. Velocity Plus has 300 cfm/ton and it does not leak either. With Unico you get approx 11 seer with a 13 seer cond unit. With Velocity Plus you get 13 with a 13. Apples for apples a better deal for all.

  6. #19
    Join Date
    Dec 2007
    Location
    winston-salem,n.c.
    Posts
    1

    heat loss

    Quote Originally Posted by hvaclover View Post
    Advice...OK . DIY...NO WAY!

    Please read the rules for posting.
    try using mastic tape,or resendial mastic.this will get rid of your duct loss.try using r8 insulation

Page 2 of 2 FirstFirst 12

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