I've got a moisture problem in a large crawl space area. There is efflorescence on the soil and nearby concrete foundation. It is a well ventilated space, but the ground just has a lot of water. Instead of installing a forced air heater which would just blow much energy out the vents, I thought about burying an electric radiant floor heating mat in the loose soil in the lowest, wettest spot. This one only uses 180 watts though $150 for the mat, and $70 for the thermostat seems a little steep.
Do you think the mat would work OK covered with loose, sandy soil in a completely unoccupied area? Maybe staked out with markers so some future handyman doesn't get a surprise?