Search:

Type: Posts; User: hvacconsultant

Page 1 of 4 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    40
    Views
    4,221

    Right, I should have been more clear. If the...

    Right, I should have been more clear. If the units are rated for 208/230V you can use 2 legs of a 3 phase service, otherwise you would be undervoltage since the 2 120 legs will get you 208V not 230V.
  2. Replies
    40
    Views
    4,221

    Yes, there is 240V/3Ph, as we refer to it,...

    Yes, there is 240V/3Ph, as we refer to it, country ass electric, but my point was that if he does have 208/230V/3Ph power, you can't run a standard 2 pole 240V condensing unit.
  3. Replies
    40
    Views
    4,221

    The 1Ph and 3Ph units with equal hp motors will...

    The 1Ph and 3Ph units with equal hp motors will draw the same power. The real advantage of 3Ph is for the motor, they like the smoother power curve and should last longer with everything else equal....
  4. Replies
    6
    Views
    420

    Usually the boiler makeup is attached at the air...

    Usually the boiler makeup is attached at the air separator so the makeup water can run through it before entering the system. The only "wrong" place for an expansion tank is at the pump discharge...
  5. Replies
    15
    Views
    1,526

    Agree with the above poster. You want 50 cfm in...

    Agree with the above poster. You want 50 cfm in bathrooms and 100-150 cfm in bathrooms with showers for moisture control. What I have in my house and recommend is to wire the exhaust with the lights...
  6. You don't use a bypass damper on Infinity systems...

    You don't use a bypass damper on Infinity systems since they are variable speed. If you use a bypass it will not like it and constantly search for the setpoint. You MUST use an Infinity zone...
  7. Replies
    18
    Views
    1,267

    IMC should have a new code in 2009 as far as I...

    IMC should have a new code in 2009 as far as I know. I've never had the AHJ ding me on OA when I use DCV, even in Chicago at permit reviews you just have to explain your methodology. Obviously, I too...
  8. Replies
    18
    Views
    1,267

    No you don't. It is at the engineer's discretion...

    No you don't. It is at the engineer's discretion to determine the appropriate people load. The IMC explicitly states that. ASHRAE also allows for a 50% reduction in people if the space is not...
  9. Replies
    18
    Views
    1,267

    I don't understand your argument here. I am just...

    I don't understand your argument here. I am just advising to use some common sense instead of blindly following codes.
  10. Replies
    18
    Views
    1,267

    If you have a 400 sqft reception area with 5...

    If you have a 400 sqft reception area with 5 chairs in it, I don't think you have to provide air for 20 people. I think that is pretty straightforward.
  11. Replies
    18
    Views
    1,267

    Thermal comfort & exhaust is in ASHRAE...

    Thermal comfort & exhaust is in ASHRAE fundamentals. For occupancy you would want to look in the Building Code & the Mechanical code. Personally I would use judgment for both, e.g. a lobby is listed...
  12. Replies
    4
    Views
    541

    You use the 5 psi with a 3.5psi drop table in the...

    You use the 5 psi with a 3.5psi drop table in the IFGC. You would then regulate the pressure to 7"w.c. at the unit. At least that is how I would do it.
  13. Replies
    12
    Views
    1,290

    Are you nuts? An unoccupied utility room needs no...

    Are you nuts? An unoccupied utility room needs no ventilation and the code agrees. ASHRAE allows up to a max of 5,000 ppm of CO2 in an 8 hour period. Two persons in a room for maintenance would take...
  14. Replies
    11
    Views
    817

    No recirculation of bathroom air. Section 403 of...

    No recirculation of bathroom air. Section 403 of the IMC. For residential, the code requires either 20 cfm of continuous exhaust or 50 cfm of intermittent exhaust. I do believe that there is an...
  15. Rules of thumb are 2.4GPM / ton on the chilled...

    Rules of thumb are 2.4GPM / ton on the chilled water side and 3GPM / ton on the cooling tower side.
  16. Design temp for Chicago is -10 and we've hit it...

    Design temp for Chicago is -10 and we've hit it more than once this year.
  17. Sorry :p typing too fast, yes that is what I...

    Sorry :p typing too fast, yes that is what I meant OA > HC > CC.

    As far as the preferred setup with PH > CC > HC, I can't say I've ever seen a unit installed with this configuration. I don't see...
  18. Cooling coil is upstream of the heating coil for...

    Cooling coil is upstream of the heating coil for freeze protection as well as dehumidification, I always call for my units to be oriented that way even if there is no application for...
  19. Stats, valves and pumps fail, you also have...

    Stats, valves and pumps fail, you also have damper leakage when the unit is off. Water + OA <32 == freeze. You have to prepare for that. Chilled water coils should be drained in the winter months...
  20. The FLA is 53 but what is the LRA? Since you seem...

    The FLA is 53 but what is the LRA? Since you seem to be pretty sure that everything is installed correctly and all the wiring looks fine, it definitely sounds like the fuse is too small. Most motors...
  21. Replies
    15
    Views
    1,292

    7 day programmable tstat with 55/85 setback is...

    7 day programmable tstat with 55/85 setback is required by the energy code for any non-residential job.
  22. Replies
    4
    Views
    418

    Your local McQuay guy should be able to tell what...

    Your local McQuay guy should be able to tell what was originally in there since you got the serial number. I'd give them a call.
  23. Replies
    27
    Views
    2,645

    I take it you don't work with JCI often then:p

    I take it you don't work with JCI often then:p
  24. Replies
    3
    Views
    762

    I'll throw some numbers out there since you don't...

    I'll throw some numbers out there since you don't want to :D

    IMC says that retail stores should have 0.3 cfm / sqft of outside air. If you have a 1500 sqft store that requires 450cfm of outside...
  25. Replies
    13
    Views
    31,683

    Granted he didn't do a load calc, but he is...

    Granted he didn't do a load calc, but he is probably right. Old furnaces were only about 70% efficient, so your BTU output was most likely around 70,000 BTU's and a new 90% 60,000 BTU furnace would...
Results 1 to 25 of 76
Page 1 of 4 1 2 3 4
Comfortech Show Promo Image

Related Forums

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