Results 1 to 3 of 3
  1. #1
    Join Date
    Jun 2013
    Austin, TX

    Useful control range of TXV

    If you take (for example) a 2 ton system with a TXV, then slow down the compressor to half speed with a VFD, you essentially have a 1 ton compressor in an otherwise 2 ton system. Yet it can be made to work just fine.

    Over what range do typical TXVs operate over? In other words, if you continued to lower the capacity of the compressor, about when would the TXV fail to operate properly? (Assume lubrication problems were solved in some other way.)

  2. #2
    Join Date
    Sep 2012
    Auckland , South Pacific.
    TXV are designed to regulate/ control with specific conditions, ie., evaporator TD., air on versus coil evaporation condition them regulate the suction super heat accordingly. By reducing evaporator duty the TXV will control superheat. The only mechanical TXV I have come across that will control down to 30% of select design is the sporlan ' O " series. Other than that electronic TXVs

  3. #3
    Join Date
    Mar 2005
    Pacific Time Zone
    Txv's also have a minimum pressure drop.

    I agree, an electronic txv would likely be the best way to go, however if you're only running your speed down to 30% and your TXV goes down to 30 maybe you almost have a matched system?
    "How it can be considered "Open" is beyond me. Calling it "voyeur-ed" would be more accurate." pka LeroyMac, SkyIsBlue, fka Freddy-B, Mongo, IndyBlue
    BIG Government = More Dependents
    "Any 'standard' would be great if it didn't get bastardised by corporate self interest." MatrixTransform - not my website.
    Versatile Hunting Dog Federation -

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