This is topic Anyone got a heater like this in their booth? in forum Film-Yak at Film-Tech Forum ARCHIVE.
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Posted by Steven J Hart (Member # 2340) on 02-04-2011, 05:56 PM:
I've got one of these electric unit heaters in the booth, and one in my garage. What has puzzled me for years is this: I can leave the thermostat at the same setting, but if its really cold outside, like -10 F the room will be quite cold, around 55 F. Today, with the temperature outside at about 28 F, the booth was over 70 F. How can I have a 15 degree temperature fluctuation depending entirely on outside temperature? The one in my garage acts exactly the same way.
As you can see from the photo, the thermostat for the unit is mounted in the lower part of the chassis.
Posted by Rick Raskin (Member # 1561) on 02-04-2011, 06:28 PM:
My guess is that your garage and the booth are both poorly insulated and that the heater cannot produce enough heat when it gets really cold outside.
Posted by Bruce Hansen (Member # 281) on 02-04-2011, 07:51 PM:
The thermostat is too close to the heater. It is not measuring room temp. It is measuring the heater temp. The thermostat needs to be moved away from the heater. I have had the same problem with fish tank heaters. The thermostst is in he glass tube with the heater, and does not measure water temp. I built a thermostat with a sensor that is in the water, and now the temp in my tanks stays constant, and I no longer have problems with ick and fungus.
Posted by Rick Raskin (Member # 1561) on 02-05-2011, 07:51 AM:
Does the heater run continuously on cold days?
If yes, then its undersized.
If no, move the thermostat.
I once had a similar problem with an electric baseboard heater and relocating the thermostat solved the problem.
Posted by Steven J Hart (Member # 2340) on 02-05-2011, 09:26 AM:
My garage is very well insulated, the booth not so much, but the booth is only about 12X20. No, the heaters do not run continuously. In fact they seem to cycle on and off about the same amount when its cold out than when its warm. I've looked into putting a wall mounted thermostat on the heaters, but have never gotten around to it. the weird thing is that if you feel the bottom of the unit where the thermostat is mounted, it never feels warmer than room temperature.
Posted by Joe Redifer (Member # 3) on 02-05-2011, 12:38 PM:
I would think it would be more effective if it were lower. Heat goes up. That means this thing has to push it down where heat doesn't want to go.
Posted by Kenneth Wuepper (Member # 1174) on 02-05-2011, 06:46 PM:
Can you run the fan continuously? That might keep the air circulating through the thermostat and the heater.
Most unit heaters of electric and the gas fired type are placed above head height in the space they are intended to heat.
A remote thermostat in the area where the occupant stands or sits is better for actually controlling the comfort in a space.
Posted by Tom Petrov (Member # 1534) on 02-06-2011, 04:15 AM:
When I worked at the drive in. We had a heating element that went red, behind it was a belt driven pulley spinning a fan of air into the elemnet.
must of been 1950's, we also had a change-over in that booth
Posted by Jake Spell (Member # 5294) on 02-07-2011, 12:41 AM:
The fan on those units is cycled based on the heater element's temp to avoid blowing around cold air. Basically the thermostat on the bottom controls the heater and another non-adjustable one controls the fan. So the heater way be running all the time and its too cold for the fan to stay on, although it sounds like its simply turning off because it cant sense the room temp very well, I have seen that many times. Moving the thermostat will solve that problem.
Posted by Mitchell Dvoskin (Member # 751) on 02-07-2011, 11:33 AM:
Hot air rises, especially if the ceiling and walls are not well isolated. Most likely, the upper part of the room is reaching the thermostat temperature while the lower part of the room is still cold.
Posted by Steven J Hart (Member # 2340) on 02-08-2011, 08:24 PM:
quote: Jake Spell
The fan on those units is cycled based on the heater element's temp to avoid blowing around cold air. Basically the thermostat on the bottom controls the heater and another non-adjustable one controls the fan. So the heater way be running all the time and its too cold for the fan to stay on, although it sounds like its simply turning off because it cant sense the room temp very well, I have seen that many times. Moving the thermostat will solve that problem.
This is precisely the reason I haven't added an external thermostat yet. I'm afraid that if the room reaches the desired temperature and I just cut the power to the unit it could warp the heating element because the fan would be cut off as well. The fan normally runs for a minute or so after the element has shut off to cool said element down. I guess If I wanted to dig into the guts of the unit I could add an external High voltage, High amperage thermostat just to the heating element circuit allowing the fan to run as normal. I suppose a low voltage thermostat could also be used with the addition of a relay to the circuit...
Steve
Posted by Jake Spell (Member # 5294) on 02-09-2011, 12:48 AM:
Well the thermostat on the front just controls the heating element if my memory is correct, there is a separate one for the fan. If it was me, I would simply move the thermostat on the front to the wall. This does require doing some wiring in the unit. If you dont feel comfortable doing it, any electrician should be able to do it for you
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