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York Evaporator

If I understand you correctly, the air will tend to take the path of least resistance. You are correct in thinking that the box plenum underneath would be better. As far as operation, what are your pressures, temps ? You are in fact cutting off half of the coils capacity and as a result this should be evident on your test results. I am curious to know what the R/A and S/A readings and also the wet bulb on the discharge of the coil.

Mike T.


  • rucomfy
    rucomfy Member Posts: 43
    York Evaporator

    Looking for info and or opinion on application of a York air handler with cased evaporator coil M# G+HA036S. The air handler is located on top of the coil plenum. My concern is that side of cased coil plenum has been cut into to serve as the return opening. It looks like half of the evaporative surface of the coil will be bypassed. There is approximately 6" clearance from the coil apex to the bottom panel, coil is inverted, like a "V". Client says works ok but I can't see how it will perform the way it really should. I would have thought a return box plenum as high as the cabinet is wide would have been much better. Any York retailers out there, before I call York rep....
    Thank-you for your help.
  • rucomfy_2
    rucomfy_2 Member Posts: 10
    Heat Check

    Performing annual maintenance on heating system under maintenance plan. WeilMcLain gas boiler, HE6 with Fields power vent (converted from UltraVent), hot water coil upstream of the air handler, aka "hydro-heat". Checked air handler and blower. Observed the return air method and wondered out loud to myself, how can this be right and how does it work. The evaporator inlet face that I can see thru the EAC opening (which is attached the side of the coil casing in question) is partially occluded and needs to be cleaned. The opening is way too small and the increased velocity has just about rendered the EAC useless. Actually the evaporator is probably the air filter... The reduced air flow could cause comfort issues and possible cycling of the boiler. I was looking to validate my concerns before approaching the client or my SM. It is kinda hard to explain this abberation to either when the system was installed this way probably at least 10 years ago. I know it does not make it right and stranger (and more dangerous) things have been done by people who have no passion for this craft.... BTW.. Mike T thanks for responding.
  • John Mills_5
    John Mills_5 Member Posts: 950

    York & Lennox have used V coils under their air handlers in the past. There is room under the bottom of the V for air to go over to the other side of the coil. BUT most of the air will go through one side so this type of application is best with bottom opening, not side.
  • don_5
    don_5 Member Posts: 4
    I can hear it now

    Its been working fine for 10 years...all I asked for was a

  • Empire_2
    Empire_2 Member Posts: 2,343
    John Read again...

    He stated that the R/A was cut into the side of the cased coil. I know what you are saying, but this is unacceptable. NEVER cut into the cased coil. If you have to knock out a wall, Do it just leave the case alone....;-)

    Mike T.
  • Marty
    Marty Member Posts: 109
    John's right

    Very common, bottom return is far better. Sounds like they just didn't buy the filter rack/panel deal from york.
  • Eugene Silberstein
    Eugene Silberstein Member Posts: 1,380
    As the others have mentioned

    As the others have mentioned, this is definitely NOT the ideal situation. With the configuration as you outleined, the velocity of the air as it flows into the cased evaporator will be greatly reduced. This will result in the air remaining in contact with the surface of the evaporator coil for a longer period of time. This causes lower evaporator temperatures and pressures, which can lead to the freezing of the coil.

    More importantly, this can result in liquid floodback to the compressor, which will cause irreparable damage to the pump.

    All in all, this is not a desirable configuration for the system.

    Hope this helps.
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