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  1. coldmaster

    Air conditioning system for a desert area

    how about a water cooled chiller?
  2. coldmaster

    hot tub heat loss

    Also you may have to consider how far from the hot tub to locate the cooler, so as not to unduly heat the beer...
  3. coldmaster

    How to optimize R410a charge in HP in cold weather?

    Why not weigh in the charge, as you mentioned? And account for the liquid line length in the weight. Why is it so costly to weigh the gas?
  4. coldmaster

    Who's paying for this time?

    Here here. You should only be charging for billable time or related research, etc. Unbillable time would be a business decision and it doesn't sound like yours to make. Killing time should be on your time.
  5. coldmaster

    Condenser Water System Design

    Consider winter operation and operation under low loads. A three way bypass valve below the roof level may help with this. The main piping should be insulated throughout the building if CW used for free cooling in the winter.
  6. coldmaster

    Need a Valve to Prevent CHW Vaporization in a High Rise Building

    Sounds to me like you need to increase the pressure to get some water up to the top stories...
  7. coldmaster

    Improve efficiency of heat recovery wheel

    If your sweet energy recovery gear is really working nice...document the energy consumption. take a look at the loads...are there opportunities to conserve? You may save "less" energy with your fancy gear if you reduce the load, but you'll be using less energy overall, which has gotta look good...
  8. coldmaster

    Pressure sensors locaiton for Variable pumping

    If you don't have pressure independent flow control valves you may be better off with the sensor "2/3" of the way down the main run. Differential pressure setpoint should be determined based on full flow and 100% system demand. I don't think you want to control the system based on any one...
  9. coldmaster

    Capillary tubes and TXV

    Why chnge a TXV for a capillary tube?
  10. coldmaster

    VRV/VRF versus Chilled water system

    Careful applying the VRF to tele/data closets. These units don't have the same low ambient operation as their smaller (1 indoor :1 outdoor) cousins...VRF won't cool during cold winters.
  11. coldmaster

    Coil Energy Recovery Loops

    The effectiveness in terms of heat recovered will be based on actual coil selections, air temperatures and relative air volumes.
  12. coldmaster

    How to get your foot in the HVAC door

    I would suggest developing a relationship with a good mechancial contractor. They can use your engineering insight and you can use their industry experience.
  13. coldmaster

    Cold Room Humidity

    Definately agree with mauricestoker...in a refrigerated room, humidity is determined by the coil TD, the match between the nominal capacity of the evap and the capacity of the condensing unit. Higher TD, colder coil, more frost on the coil, and out the drain during defrost. Definately make...
  14. coldmaster

    Use of Solenoid Valve in Heat Pump Liquid Line

    The "drop" solenoid prevents refrigerant migration during the off cycle. I believe the manufacturer is concerned with the total amount of refrigerant in the system once you get into longer pipe runs. Liquid refrigerant will migrate to the coldest part of the system, then flood back to the...
  15. coldmaster

    Large Scale Plotter Load

    The question I keep coming up with in this situation: what is an appropriate diversity factor to apply to the nameplate watts? maybe 50%
  16. coldmaster

    Wind effect on heat loss/gain through walls

    Wind speed and convection coefficient are taken into account using ashrae. Although I've never been able to make any sense of the discussion regarding RTS or heat balance...I believe those methods are innappropriate for hand calculations...I believe these are for the authors of computer...
  17. coldmaster

    A/C makes air feel cold and damp

    That shouldn't be too much air for that room.
  18. coldmaster

    Energy Saving Window Covers?

    There's a whole industry devoted to exterior shading. I'd be interested in using an exterior shade or "sun louver" that takes advantage of the different angle of the sun, summer vs winter. At winter angles the sun hits the glass, during summer time the glass is shaded.
  19. coldmaster

    A/C makes air feel cold and damp

    You want that compressor to run more, not less. the longer the compressor runs, the longer the cooling coil is cold, the more moisture is pulls out of the air...satisfy the space too quickly and the compressor shuts off and stops "making water." The unit should cool down the room in hours...
  20. coldmaster

    A/C makes air feel cold and damp

    Cold and damp is classic oversized. Load is less than 2 ton in the space. Take a good look at the load calculation before you throw down for new central system.

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