Cold weather delights!

[G Cook]

Hello all,

This may seem like a silly question.....

Been at a couple of cold rooms today which are suffering from the cold. Condensing units outside with no fan speed controller fitted so unit ends up tripping on lp switch.
When the units were started back up again i noticed that the site glasses were bubbling.

Can the extreme cold (it was -22.4 celcius here the other morning ) cause the bubbles in the glass or am I barking up the wrong tree?

Thanks in advance

[chemi-cool]

You need head pressure controll also on the first fan.
And yes, its the low temp that causes the bubbles.

[G Cook]

Cheers Chemi, I take it that its due to the high side pressure being dropped to such a low level. What is the actual reason that there is not a solid stream of liquid?

[chilliwilly]

Did the bubbles clear or did they persist?

[mad fridgie]

Cheers Chemi, I take it that its due to the high side pressure being dropped to such a low level. What is the actual reason that there is not a solid stream of liquid?

A number or reasons.
You do not have the correct mass flow of refrigerant (hence tripping on LP)
Some of the refrigerant is held up in the condensor (no all flowing) balancing heat transfer

[G Cook]

The bubbles persisted chilly.

[jpsmith1cm]

http://www.sporlanonline.com/90-30.htm

http://www.sporlanonline.com/90-31.htm

http://www.sporlanonline.com/90-30-1.htm

These are the guidelines that i follow for charging units that will see temperature extremes.

[cadwaladr]

tell me about the cold got 2 vans with gah units fitted ,they are heat/cool units trying to maintain +16 celcius and they cannot do it arghhhh

[djbe]

tell me about the cold got 2 vans with gah units fitted ,they are heat/cool units trying to maintain +16 celcius and they cannot do it arghhhh

They will struggle in low ambients, have they got heater pads in the drain pans? If they have perhaps you could add a relay to energise them in heat mode which will add a bit more?