Fahrenheat Ceiling-Mount Industrial Heater - 7500 Watt, Model# FUH724

I installed this heater in a 3-car mostly uninsulated garage. Because I wanted to mount it higher than would be convenient for controlling the thermostat and wanted to be able to turn it off and on remotely, I wired an external thermostat to the heater.The basic requirements are a thermostat, a power source less than 30V DC or AC, a relay and some 2 conductor wire.Parts I Used- Thermostat - ICM Controls FS1500L Garage Stat, which has a digital display and will work with millivolts to 30VDC/VAC control line.- 5VDC power adapter - 5VDC 500ma power adapter. Virtually any 5VDC power adapter, such as a charger for a cell phone will work. You will need to know which wire is positive and which is negative.- Relay - I used a SunFounder 2 Channel DC 5V Relay Module because I had one. I suggest finding a relay module that uses screw-to-tighten terminals rather than the pin terminals on the model I used. It will simplify the wiring process. This type of relay is commonly used for Arduino projects.- Wire - I used standard 2 conductor solid thermostat wire between the heater and the thermostat.Wiring It Up- Remove the OE thermostat in the heater, which is connected between the AC input terminal L1 and terminal 1 on the contactor assembly. I plugged the big hole in front with a ½" hole plug.- Mount the relay module inside the wiring area of the heater. I used a couple of aluminum standoffs to ensure the bottom of the relay board didn't short out on the chassis and ensuring that it was securely anchored.- Connect the Normally Open connections on the relay to the two previous thermostat connections. These use standard slide-on connectors. Polarity doesn't matter, as it is switching AC and the current is not high, although I didn't measure it.- Connect the 5VDC supply positive wire to the R terminal on the thermostat.- Connect the 5VDC supply negative wire to the white wire of the thermostat cable.- Connect the red wire to the W terminal of the thermostat. There is space in the thermostat housing for small wire nuts to make the connections.- The relay module in the heater has connections for power (Vcc, GND) and actuation (IN1, GND). I jumpered the power and actuation connections so that the relay board is powered and actuated simultaneously. This eliminates the need for a separate power connection for the relay board.- Connect the red wire to the Vcc/IN1 and white to GND.How It WorksWhen the thermostat sees a temperature below the set point, the internal relay closes, causing the relay module that you installed in the heater to be powered and the relay to be actuated, turning on the heater.VariationsThe only constraint on using different components is that your power source must match the need for actuating the relay. If you have 24VAC available near your thermostat mounting location, you'll need a 24VAC relay for mounting in the heater.UsageI use the On/Off switch on the thermostat to determine when heating occurs. I set the thermostat to 65. I usually turn it on an hour or so before going out to the garage. This will get me a 7-8 degree temperature rise in a 3-car largely uninsulated garage. My only challenge is remembering to turn it off at the end of the day so that I don't keep the garage warm all night.

After reading other reviews of this heater, I chose this as the solution for heating my detached workshop.I had read that the spacing inside was a little tight for wiring the power cord, and this was indeed true. Not a huge deal, but could have been laid out a little better. More frustrating was that the knockout for the 1" access hole was very difficult to remove -- much more difficult than in other service panels I've used. One half of it tapped loose pretty easily, but the other half would not even pry out without deforming the side wall of the case a bit A few taps with some body hammers and it was back in shape. That could have been easier, though.One pleasant surprise I found when reading the included manual is that the unit can easily be configured for any of the following wattages: 3750, 5000, 6250, and 7500. I almost bought the smaller 5000 W unit because I was concerned that my 70 A service to my shop might not be enough to power this heater, air compressor, and other power tools I often use. Now that its installed, it appears to not be a problem, but I wish I had known that it was configurable like this as I would not have hesitated at all buying this bigger unit. If it does trip my main breaker, I can just move a wire jumper or two and lower the heater's power consumption. Brilliant. Of course, it would then put out fewer BTU's, but that's the tradeoff.In general, I'm impressed with the unit's construction and performance. The fan moves a good amount of air and it fairly quickly raised the temperature of my 864 sq ft shop to a comfortable level. Yes, there are hot and cold spots due to lack of general air circulation, but that could be rectified with small fans in a couple of strategic locations. Using an infrared temperature meter I measured the temp of the floor to be about 47 degrees, objects at mid-height at about 55 degrees, and the ceiling in the middle of the room a toasty 70. That's with the heater thermostat set on one notch above the LO setting (and it's now 25 degrees outside). I'm confident this heater could bring my work space up to 60 or 70 if the thermostat was set higher. I'm anxious to do that test on the next really cold day (has been pretty mild so far this winter). Keep in mind my walls and overhead door are insulated. It would probably not do so well if that wasn't the case. I might consider blowing insulation in the attic space now that I have heat to keep in.I would definitely recommend this heater to anyone looking for a heating solution for their unheated space.