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  1. #14
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    Quote Originally Posted by cmajerus View Post
    your not the only one, and my guess there are more than just 2 companies out there. We only had 2 major problem child jobs, but neither are perfect to this day, just tolerable. One question I would have is are there any other indoor units that would be compatible to the duct system installed for the HI-V? ie: round metal duct, not fiber pipe.
    You can use round metal for HV.
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  2. #15
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    Apr 2007
    Location
    Exeter, NH
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    Iceing has never been an issue

    It's always the other way around, getting the evap temp to 38 is the problem. Balancing the charge when there is too much load, not enough loads, too humid, too cold out doors or any other associated problems and you can be here for hours.

    All my problems have been under sizing and not taking stratification into account, I actually believed the story about how fan forced air movement would eliminate it... Wrong (well, maybe in Canada it dose).

    We won’t go into the flex ducts failing, after all that wasn’t their fault, they didn’t make them… Or the fact the fan motors fail due to running on low voltage (rheostat controlled). Change is good… Now that these problems have been corrected and the devalued dollar they have essentially priced themselves out of the market. I have to charge 2K more for the Hi-V over a conventional system.

  3. #16
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    Keep pricing references out of the public forums.
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  4. #17
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    Sep 2007
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    Kenilworth NJ
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    Quote Originally Posted by heatkits View Post
    It's always the other way around, getting the evap temp to 38 is the problem. Balancing the charge when there is too much load, not enough loads, too humid, too cold out doors or any other associated problems and you can be here for hours.
    So the system either is at a 45-50 degree suction line (under-charge), or it is tripping on high head (over-charge). getting the magical 38-42 with out popping safeties is the issue. Is that right?
    Hmmmm....smells like numbatwo to me.

  5. #18
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    Sep 2007
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    Kenilworth NJ
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    Quote Originally Posted by beenthere View Post
    You can use round metal for HV.
    I actually heard of some guys using central vacuum cleaner supply pipe for longer 2" duct runs. the inside is VERY slick to keep dust from accumulating, and it is 1/4 the cost per foot (I'll edit that out if I need to ) and eliminates the need to compensate for low flows on longer runs, just make sure you end the run with 10' of the regular hose for sound attenuation.
    Hmmmm....smells like numbatwo to me.

  6. #19
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    A 2" supply, carrying 40 CFM, is about 1800 FPM. Ain't gonna be much dust collecting in a pipe.
    At 30 CFM its around 1375 FPM.
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  7. #20
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    Kenilworth NJ
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    Quote Originally Posted by beenthere View Post
    A 2" supply, carrying 40 CFM, is about 1800 FPM. Ain't gonna be much dust collecting in a pipe.
    At 30 CFM its around 1375 FPM.
    I agree, HVAC guys don't care about dust, we have filters for that, and the velocity is high as you say. i was illustrating that the pipe is designed for central vac systems, where dust is a concern. and as such it offers very low friction losses, when compared to the flex that would otherwise be used.

    Also the fittings on the Vac pipe is as Heatkits pointed out, compatible with the Hi-V duct fittings, since ESP uses the same fittings on their flex.
    Hmmmm....smells like numbatwo to me.

  8. #21
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    Apr 2007
    Location
    Exeter, NH
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    59

    right you are...

    However, we're using lower grade efficiency condensers with no pressure switches, just a temperature overload on the compressor. They seldom trip from laboring the motor.

    Had I to do it again, I would have increase all the units by at least a half ton or better.

    For the most part; once they got balanced and people learned how to run them, most are satisfied with them.

  9. #22
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    How to run them???
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  10. #23
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    Sep 2007
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    Kenilworth NJ
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    Quote Originally Posted by numbawunfela View Post
    So the system either is at a 45-50 degree suction line (under-charge), or it is tripping on high head (over-charge). getting the magical 38-42 with out popping safeties is the issue. Is that right?
    Right you are...
    Quote Originally Posted by heatkits View Post
    However, we're using lower grade efficiency condensers with no pressure switches, just a temperature overload on the compressor. They seldom trip from laboring the motor.

    Had I to do it again, I would have increase all the units by at least a half ton or better.
    So the temp overload on the compressors were cutting the compressors out due to high heat load before the charge was sufficient to bring the comfort level in the home to the setpoint. you would oversize the condensers...right?

    Out of curiosity, did you double check the ari ratings for the matched pair condenser to Air-handler? I have not made it a habit myself, but after I saw what the difference MIGHT be as posted below, I think I will start. Could it be the system was sized to the nominal capacity and not the actual capacity as matched to their individual condensers?

    The goal is not to point a finger, but rather to get my head wrapped around the proper application of these systems. I would rather go with an ari rating than a blanket 1/2 ton oversize, unless of course you did go with the ARI rating already.....
    Hmmmm....smells like numbatwo to me.

  11. #24
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    Sep 2007
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    Kenilworth NJ
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    Quote Originally Posted by beenthere View Post
    How to run them???
    They ran a little flex if needed from the standard take off to the hard plastic pipe to accomodate any weird angles if there are any. then run the little 2" pipe like plain round duct, cutting it with a copper tubing cutter, and gluing in the els and such similar to PVC pipe. then pushing the last 10' length of flex onto the end of the tubing, since the connectors are literally the same. then strap it down if you feel like you need to.
    Last edited by numbawunfela; 06-27-2008 at 09:24 AM.
    Hmmmm....smells like numbatwo to me.

  12. #25
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    Apr 2007
    Location
    Exeter, NH
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    59
    Hi-V systems are a subtle form of conditioning with very low volume of air movement. Deep cycling defeats the inherent design of the system and setback thermostats actually work against it. We tell our customers to just set it at a normal temperature 74 to 78 range and forget it... The more they try to manage it or conserve energy the more it will cost to run and the more uncomfortable they will be.

    We only use digital, non-programmable thermostats with a 1 or 2 degree dead band in them. We also recommend shorter filter service due to the "always on" design.

  13. #26
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    Sep 2007
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    Quote Originally Posted by heatkits View Post
    Hi-V systems are a subtle form of conditioning with very low volume of air movement.
    We only use digital, non-programmable thermostats with a 1 or 2 degree dead band in them. We also recommend shorter filter service due to the "always on" design.
    Cool - that is helpfull

    Not the kinda thing one would get from the literature. thanks again for your input.

    You were saying about the condensers?
    Hmmmm....smells like numbatwo to me.

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