Search:

Type: Posts; User: 19characterusername

Page 1 of 5 1 2 3 4

Search: Search took 0.01 seconds.

  1. Replies
    1
    Views
    432

    1. Use a psychrometric chart with the protractor...

    1. Use a psychrometric chart with the protractor looking thing sitting above the saturation curve with sensible heat ratio markings on it.
    2. You take your space sensible heat ratio and plot that...
  2. Replies
    1
    Views
    635

    VRV or VRF + hydronic heat

    Apologies if this has been posted before, wasn't having much luck with my searching. I'm designing a job where we may be using a combination of a VRF with perimeter or radiant floor hydronic heat. ...
  3. Typically CO2 should be a maximum of 700-900 ppm...

    Typically CO2 should be a maximum of 700-900 ppm or a maximum of 400 ppm over ambient. Also sensors need to be calibrated and in every zone to make a VAV or multiple zone system work right with DCV....
  4. All of the above. Your local building code may...

    All of the above. Your local building code may have higher rates than would be determined based on a performance method based on people and occupancy or chemical contaminants as can be found in...
  5. Best bet in this scenario is to measure the...

    Best bet in this scenario is to measure the number of rows, tube size, face area and fin density (count the number of fins in 10cm). Then give that information along with the flow and return temps as...
  6. Replies
    12
    Views
    1,052

    Things to check: 1. Can your chemical go down...

    Things to check:
    1. Can your chemical go down the local sanitary sewer?
    2. Are storm and sanitary combined (like nyc)?If 1&2 are yes then you're done.
    3. If not then maybe you use containment and...
  7. Running VAV w/o reheat is doable but it requires...

    Running VAV w/o reheat is doable but it requires return air reset, average or critical space reset (easy with DDC boxes). For return air reset make sure that sensor doesn't see mixed air or you...
  8. Replies
    4
    Views
    1,865

    Line volt wiring not to code due to inadequate...

    Line volt wiring not to code due to inadequate support.
  9. Run through diagnostics with your LG rep. ICs can...

    Run through diagnostics with your LG rep. ICs can be damaged without it being visually apparent. IC damage is typically only functionally apparent.
  10. I've run into this on VRF units with the same...

    I've run into this on VRF units with the same story. You need a robust ground (CW lines don't cut it according to the engineering manuals, you need a proper grounding rod) and I'd suggest TVSS for at...
  11. Multistack like any other brazed plate condenser...

    Multistack like any other brazed plate condenser system cannot be used on open condenser systems due to fouling. Full stop. A proper multistack design must incorporate a plate and frame in the...
  12. If there are balance valves on the bypass legs...

    If there are balance valves on the bypass legs (there should be to mimic the pressure drop of the coil) then you can add VFDs to your pumps and go to variable flow pumping and save a boatload of...
  13. Replies
    5
    Views
    839

    This sounds like it could be a typical thermally...

    This sounds like it could be a typical thermally broken construction. The panels would overlap the frame on the unit interior so the frame isn't exposed to the air stream and the neoprene gasket...
  14. Replies
    5
    Views
    751

    Yeah Munters and similar desiccant systems are a...

    Yeah Munters and similar desiccant systems are a better option performance wise but I think $/CFM is too high for the developer. The architect won't give me the space either. My battle is for...
  15. Replies
    5
    Views
    751

    DX dehum makeup air units

    Looking at Reznor, Aaon, Daikin-McQuay Rebel, other mfg's hot gas reheat units. For a luxury condo corridor unit. Any experience good or bad? The Rebel is new, and I see a lot of substitutions to...
  16. Replies
    19
    Views
    3,142

    Retail, office, residential, everything. It has...

    Retail, office, residential, everything. It has to meet natural ventilation requirements or be provided with mechanical ventilation. Even when you satisfy natural vent requirements, there's no...
  17. Replies
    19
    Views
    3,142

    Min OA depends on occupancy. IMC2009 and ASHRAE...

    Min OA depends on occupancy. IMC2009 and ASHRAE 62 are 0.06 CFM per sq ft plus 5 CFM per occupant for most occupancies. Gyms, classrooms and other spaces with higher activity rates or space rather...
  18. Replies
    19
    Views
    3,142

    It's in all IMC based codes and just about...

    It's in all IMC based codes and just about everything else. When a space is occupied you have to ventilate it mechanically or naturally (5% of floor area in operable window free area and nothing more...
  19. Replies
    19
    Views
    3,142

    The economizer module also handles the min OA...

    The economizer module also handles the min OA position for ventilation needs during occupancy. If your OA and relief dampers aren't at least slightly open when your space is occupied, you likely have...
  20. Not sure. I wasn't on the survey, a colleague...

    Not sure. I wasn't on the survey, a colleague took the picture. We were only concerned about moving flues out of the way of some planned higher work. This was interesting but out of my scope.
    ...
  21. Gooseneck + Exhaust fan = Exhaustneck or Goosefan?

    Nice, eh?
  22. Replies
    36
    Views
    3,722

    I used to work in patents. Patent quality is...

    I used to work in patents. Patent quality is often so incredibly poor. Things that ought not to have been patentable get patent protection due to sloppy prior art examination. Also the people who are...
  23. Replies
    6
    Views
    1,982

    Copper can be easier to deal with if you don't...

    Copper can be easier to deal with if you don't want to pay attention to water quality on closed systems. Copper won't develop flaky rust prior to installation which can be a problem when...
  24. Replies
    14
    Views
    2,641

    Shouldn't the fan starter or VFD have contacts...

    Shouldn't the fan starter or VFD have contacts for shutdown by the FAS? The controls either keep power and are aware the FAS has shut down the fan or could also lose power and shut the unit down...
  25. At nominal 200-250 of borehole ft/ton equipment,...

    At nominal 200-250 of borehole ft/ton equipment, that sounds like it would be 20 to 25 k to drill plus equipment and installation less the tax credit. Which isn't bad, I guess. I'm not sure how...
Results 1 to 25 of 107
Page 1 of 5 1 2 3 4
Comfortech Show Promo Image

Related Forums

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