The Lasko 6435 is the top-rated crawlspace heater as of November 2015, according to customer reviews on Amazon.com. Other popular heaters include the Lasko 6405 and the Camco 57331 Olympian Wave.
The Lasko 6435 space heater offers customers a remote control and oscillating heater with a self-regulating ceramic element. Its popularity comes from its automatic overheat protection and low price. As of November 2015, the Lasko 6435 has a 4.5-star rating and sells for around $48.
The Lasko 6405 provides widespread oscillation and an adjustable thermostat with an automatic shut-off timer. It provides 1,500 watts of heat and sells for around $48. Its rating is 4.6 out of 5 stars.
The Camco 57331 Olympian Wave heater is a higher-end model, selling for around $175. It is adjustable from 1,600 to 3,000 BTUs per hour and is not only a portable space heater, but can also be mounted on a wall. This heater is popular among shoppers and has an overall rating of 4.4 out of 5 stars.