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Drew
17-08-2013, 01:31 AM
Hi all,

there seem to be many ways to run freezer drains:

insulated, uninsulated, internal trace heat , wrap around trace heat, various wattages,
pvc or copper , traps or no traps, heaters that are made up or premade ones.

I always have issues with them failing or having dead spots. What wattage should I use on a freezer running at -20c. With an insulated PVC pipe?

has anyone got a good solution? What is the hottest the self regulating ones can get.
ive heard stories of insulated PVC pipes melting? Why would they do this if the heaters can regulate themselves? Surely they shouldn't get to hot? We get 5, 10, 15 watt per foot I think. Would the 15 w/ft offer 15w max, but shut down to 0w/ft?

Drew
17-08-2013, 01:37 AM
What temps should they try and maintain the pipe at?

FreezerGeezer
17-08-2013, 04:56 AM
For your second post - it only really needs to keep the temp. slightly above 0*C to avoid any sitting water freezing. For the rest, it seems to be down to personal preference or what's available at the time. Most freezer drains I've seen are PVC iirc. I don't recall ever seeing one that'd melted.

1mikeefc1
17-08-2013, 01:52 PM
We always use 22mm brass/copper drain and fittings, most of them are originally put in with drain line heater inside but once its being replaced we use external drain heater wrapped around it and fixed with tie wraps. Seems ok to us until the the goes down anyway.

Rob White
17-08-2013, 09:30 PM
Hi all,

there seem to be many ways to run freezer drains:

insulated, uninsulated, internal trace heat , wrap around trace heat, various wattages,
pvc or copper , traps or no traps, heaters that are made up or premade ones.

I always have issues with them failing or having dead spots. What wattage should I use on a freezer running at -20c. With an insulated PVC pipe?

has anyone got a good solution? What is the hottest the self regulating ones can get.
ive heard stories of insulated PVC pipes melting? Why would they do this if the heaters can regulate themselves? Surely they shouldn't get to hot? We get 5, 10, 15 watt per foot I think. Would the 15 w/ft offer 15w max, but shut down to 0w/ft?

Get the drains out of the room as early as possible
and keep the drain above freezing all the time.

Use an internal with low wattage and keep them on 24 hours a day
to ensure that all water inside is free to flow.

Use copper because it is stronger but it will dissipate the heat
more. The use of insulation is not required if the drain has
an internal heater.

Only wrap the heater on the outside if you can't get access
to the internal drain.

Regards

Rob

.

PaulZ
20-08-2013, 11:17 AM
Hi Drew
I agree with Rob regarding the internal heaters, using copper pipe and making them as short as possible in the room.
The internal heaters keep the heat inside the pipe where you need it and I would insulate the drain.
You definitely need a trap outside the room, this stops moisture being drawn up the drain which will block it as well.
If you wrap the heater around the pipe it will have to be insulated otherwise it will not work that well if at all.
Paul

Peter_1
20-08-2013, 07:42 PM
We use a silicon heater of 100 W inside a non insulate PVC tube.
Air traps outside the freezer.
Avoiding the heater touches somewhere against itself.