Hot gas control

[multisync]

We have been asked to provide 4 x 20kw condensing units with hot gas to a single AHU (100% fresh air)Reading the spec Airedale seem to be the implied choice.How does the hot gas control work and how should we set it up etc?

Multisync
london

[Andy]

Hello Multisync:)

hot gas bypass on pressure. When the evaporation drops the mechanical valve opens to inject hot gas into the liquid on the evaporator side of the expansion valve.

Kind Regards Andy:)

[dougie]

Hi Multisync

what refrigerant are you using? Usually say with r.22 you would set it up for about 45 p.s.i to maintain 60 p.s.i. To adjust take the top off the valve and alter with allen key or srew driver to increase or decrease the pressure. The hot gas injection will help to stop the evaporator from iceing up.:o

[Jase]

Hot gas injection is usually used upon low load. The valve is set up to a predetermined value which will keep the evap temp off the zero. The valve may well operate too upon system start up. I'm pretty sure Airedale incorporate a solenoid valve as part of their set up, but they will manufacture as to client speification.

regards
Jase