Two ways to get heat out of a rooftop unit. They cost different amounts, work in different weather, and need different ceiling assemblies. Decide this before you order, because the ceiling assembly has to match.
Side by side
| Heat strip (heat-ready unit) | Heat pump unit | |
|---|---|---|
| How it heats | An electric element in the ceiling assembly, like a space heater in the ceiling. 5,600 BTU (38203-4551) or 6,000 BTU on the ultra-low Mach 8 (37203-4551). | Reverses the refrigerant cycle and pulls heat from the outside air, so it gets several times more heat per watt than a strip. |
| Works down to | Any outdoor temperature. Output is small, so it takes the chill off; it does not heat a 35 ft fifth wheel in January. | Best above about 40F outdoors. Output falls as it gets colder and the unit shuts off near freezing. Keep the furnace for cold nights. |
| Power draw | About 16 A on heat. Runs on 30 A service, not with the microwave. | About the same as cooling, roughly 14 to 16 A. |
| Cost over cool-only | About $100 for the strip, plus a heat-ready assembly (9430E715, 9430-725, or the 8430A635 ChillGrille). | About $130 to $300 more for the unit than the same series cool-only, plus a heat pump assembly (9630-725, 9630A715, or the 8630A635 ChillGrille). |
| Series available here | Mach 3, Mach 15 and Mach 8 Plus air conditioners with a heat-ready assembly | Mach 15, Mach 10 and Mach 8 Plus heat pumps |
Who should buy which
- Cool only: Florida and Gulf Coast full-timers, summer-only campers, anyone with a working furnace who never camps under 50F. Most buyers.
- Heat strip: shoulder-season campers who want to knock the morning chill off without lighting the furnace. Cheap, simple, no extra noise.
- Heat pump: anyone on electric hookups through fall and spring in the Southeast, Southwest or California, where nights run 40 to 60F. It saves propane every night it runs.
The matching rule
Heat strips do not fit cool-only ceiling assemblies. Heat pump units need a heat pump ceiling assembly (9630 or 8630 family), which has the heat pump controls built in; a 9430 assembly on a heat pump unit gives you cooling only. The one exception is the plenum-only 9430-4552 with the 9530A751 heat pump control package. Kate RV Heat Pump Complete Kits and the heat-ready kits are built so the assembly matches the unit.