Patent ID: 7625578

Claim:
A method for dispensing a volatile material from a heating device having an enclosed heating chamber designed to hold a volatile-impregnated substrate there within, the heating chamber having chamber walls and being vented to the outside air; a fuel burner; and an air flow path to guide hot gases generated by the fuel burner past the substrate to heat the substrate and release the volatile material therefrom, the method comprising the steps of: a. providing a substrate holdable by the enclosed heating chamber, the substrate having: i. granular particles adhered together to form a body having a network of pores and passages, the interior surfaces of which are non-reactive and non-absorptive with respect to the volatile material to be dispensed; and ii. the volatile material to be dispensed, disposed in the pores; b. installing the substrate in the heating chamber; and c. activating the fuel burner to release the volatile material from the pores, which volatile material is then dispensed; wherein the volatile material is an insect control active material and the device is configured such that the volatile material can be dispensed at an insect controlling rate due to application of heat until the amount of the volatile material remaining in the pores is no more than 10% of an amount of the volatile material present in the pores immediately prior to the activating step and wherein the volatile material comprises an insect control active ingredient selected from the group consisting of natural pyrethrins, pyrethrum extract, synthetic pyrethroids, and mixtures thereof.