Condensate traps for hot gas defrost blowers

[willysmb]

Hi all
Are liquid condensate traps required on gravity feed flooded blowers to keep the coil empty during defrost?

[RANGER1]

willysmb,
I would say yes to that.
You need latent heat to defrost it, so any condensate would & should be drained away.
Normally the surge drum has a gas powered valve on liquid in & return to surge drum.
Hot gas is piped in to one or the other on unit side of gas powered stop valves to pressurize evaporator.
Liquid is drained back into surge drum to clear it & as it is formed during the defrost.

[willysmb]

Thanks Ranger,
The problem im having is ice building on the bottom few rows of the coil,maybe 8 inches or so.The coil (guntner) has good drainage built in in the headers,but the piping between the evap and surge drum have no p-traps,just elbows.I think Im collecting condensate during hotgas,blocking off the bottom rows from seeing any hot gas with a liquid seal...

[RANGER1]

Thanks Ranger,
The problem im having is ice building on the bottom few rows of the coil,maybe 8 inches or so.The coil (guntner) has good drainage built in in the headers,but the piping between the evap and surge drum have no p-traps,just elbows.I think Im collecting condensate during hotgas,blocking off the bottom rows from seeing any hot gas with a liquid seal...

For some reason I thought you also had a liquid float drain system. It couild be used at bottom of header if you had enough room.
I'm assuming you are regulating hot gas return to surge drum with a regulating valve set at around 75-80psi?

Will you consider repiping this unit to make it a bit better, as you suggest trap off bottom of header?

[Segei]

Usually, bottom of the coil will not defrost properly, if back pressure regulator located higher than coil bottom. It would be good to look at the sketch of this evaporator.

[willysmb]

Z
For some reason I thought you also had a liquid float drain system. It couild be used at bottom of header if you had enough room.
I'm assuming you are regulating hot gas return to surge drum with a regulating valve set at around 75-80psi?

Will you consider repiping this unit to make it a bit better, as you suggest trap off bottom of header?
no liquid float drain. R22system gravity feed flooded blower .defrost holdback reg set to 85 psi ,reg located on rooftop 7ft above blower,no traps,just trouble LOL! I agree with all replies...might have to cut into piping...

[chemi-cool]

You can add a defrost heater under the coil activated in parallel with the hot gas solenoid.