CheapHeat™ Direct Discharge System

The CheapHeat™ NT-DH19 Add-on Electric Heater, is designed work with the Suburban Direct Discharge Gas Furnace models NT-12, NT-16, or NT-20. These furnaces are commonly found in Tent Trailers and Pick-up Campers. The CheapHeat™ electric heater frame, fits between the grill and the mounting flange, onto the end of the direct discharge gas furnace, is unique in its manufacture because the heater controller is built inside the frame. This new self contained design simplifies the installation process, by eliminating the need for additional wiring, and controls external to the heater.
As with all RV Comfort Systems products this heater kit is UL certified and RVIA compliant. Because of the NT-DH19 open wire electric coil, and hollow frame design it offers virtually no backpressure to the Gas furnace fan. In fact, the electric heater and frame has more than 4 times the free air passage of the original gas furnace grill that is provided by the furnace manufacturer. For additional safety the heater is protected by an auto reset 140 F degree high limit switch backed up by an inline 262 F degree High temperature fusible link failsafe, which is connected directly to the heater coil itself.

Technical

The CheapHeat Ductless system operates off ofa 20 amp 120 VAC breaker via its internally mounted controller consisting of UL certified PC Board, with a DPST relay rated 240 VAC, 30 amps, which turns the 16.5 amp 120 VAC electric coil on and off. The second relay is a SPST rated at 12 VDC, 10 amps which turns the gas furnace fan motor (2.8 amps @ 12 VDC) on and off in tandem with electric heater relay. The SPDT 12 VDC override switch is mounted to the access panel cover, and is used to switch the thermostat between the onboard heater controller and the gas furnace PC board. When the switch is in the Electric Heat mode the gas furnace controls are bypassed, and NT-DN19 electric element and furnace fan will turn on and off in accordance when the room thermostat call for heat. When the override switch is in the Gas Heat mode, the room thermostat is connected back to the gas furnace PC Board, and the gas furnace will operate as it did before the electric heater was installed.

Compatibility

Works On: The NT-DH19 is designed to work with the Suburban NT-12, NT-16, and NT-20 Series direct air discharge RV Gas Furnace.

Output: Because a RV Gas furnace is only about 60% efficient (40% of heat goes out the flue) and it has a pre-purge (60 seconds) and post-purge (90 Seconds) cycle of approximately 2 ½ minutes for every heating cycle. The overall output during a given heating cycle is reduced as follows:

Note: When calculating heater run time on any average RV, it is assumed (industry standard) that the total run time will be somewhere between a 25% to 75% duty cycle, depending on outdoor temperature. By increasing run time with the CheapHeat™ system, the consumer can exceed the heating capacity of the 12,000/16,000 btu gas furnace’s and meet 86% of the 20,000 btu gas heaters output.