IMPO, (that's in my PROFESSIONAL opinion) heat strips are not worth their relatively modest cost.
I had 2 roof units on me 1998 Monaco diesel pusher and the only thing they would do is take a slight bit of chill out of the air. They weren't meant for heating duty, and at a tiny 6-800 watt draw with air rushing across them, they just don't do the job.
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
Lew Farber...RVIA Certified Master Tech...ABYC Certified Master Marine Electrician
SOLAR TECH ENERGY SYSTEMS, INC.
AM SOLAR ...MAGNUM…VICTRON ENERGY...LITHIUM & LIFELINE BATTERIES…MARINE REFRIGERATION