a/c icing up coil on open display cooler...

[freeeze43]

anybody find this to be a problem is that a/c diffusser is right above open display cooler, this is a federal open type with no defrost except when cut-out pressure is met,a/c blowing around 65 deg. air at system, should this display case be moved or diffusser disconnected or blocked off, any recommendations on getting around this... thanks..

[Jabarco]

anybody find this to be a problem is that a/c diffusser is right above open display cooler, this is a federal open type with no defrost except when cut-out pressure is met,a/c blowing around 65 deg. air at system, should this display case be moved or diffusser disconnected or blocked off, any recommendations on getting around this... thanks..

What refrigerant is in this unit and what are the Low pressure control settings (cut-out & cut-in).

Jabs

[yotaman16]

the diffuser should be moved, it will blow 55 degree air into the case moving the 30 degree air out.. The case might work fine but will have to work harder for sure..

[hvac wiz 79]

at local wawas in this area (nj) i see the returns right above cases & i always wondered what effect if any it had on either system

[itsiceman]

Never had one ice up because of the duct work but have seen them not getting down to temp. They moved the vent and problem solved.

[freeeze43]

What refrigerant is in this unit and what are the Low pressure control settings (cut-out & cut-in).

Jabs

r22 with cut out at 64psig and cut in at 35 psig

[gas_n_go]

Your settings are too low for not having a defrost clock. I cant tell you exactly what you want without knowing what temp your trying to hit. 55/70 is close

[Jabarco]

r22 with cut out at 64psig and cut in at 35 psig

The settings you have are a good setting for a walk-in cooler but on an open case with R22 I would use 66 psig as cut-in & 40 psig as cut-out.

Jabs

[freonguy]

anybody find this to be a problem is that a/c diffusser is right above open display cooler, this is a federal open type with no defrost except when cut-out pressure is met,a/c blowing around 65 deg. air at system, should this display case be moved or diffusser disconnected or blocked off, any recommendations on getting around this... thanks..

The air from a diffuser WILL disrupt the invisible air curtain and cause spillage of the cold, dry air from the case - so you make that air up with warmer, more humid air from the HVAC system in the store - two things will happen - iced up case and in the very least, inability to hold temperature/ longer run time.

Does the case have a seperate air curtain? If so, ensure that portion of it is working properly.

Years ago, Hussmann used to publish the cases had to be out of any air stream ( that includes ceiling fans ) and the design parameters dictated 75 F DB and 50% RH maximum - food for thought.