Toyotomi's Wall-Vented, Oil-Fired Space Heater

The Japanese company Toyotomi introduced its OM-22 oil-fired, pilotless, wall-mount space heater in the U.S. in 2001. It is designed to operate on No. 2 fuel oil or kerosene (No. 1 fuel oil) and relies on an external fuel tank (typically installed in a basement). Like Rinnai wall-mount space heaters, this is a through-the-wall-venting product with sealed combustion. The OM-22 has three output levels: 8,000, 15,000, and 22,000 Btu/hour. The efficiency, at 90%, is high for oil-fired heating equipment, and the combustion is relatively clean. According to Patrick Miller, of Nelson & Small, Inc., the distributor of Toyotomi products for the Northeast, the OM-22 vaporizes the fuel and burns the vapor, rather than directly burning the liquid fuel. A porcelain rod is heated electrically to initiate that vaporization. The unit uses 275 watts of electricity in the preheat mode and 46 watts during operation (primarily for the fan).

Researcher Dr. C. R. Krishna of Brookhaven National Laboratory, who studies fuel oil combustion, calls vaporization the “holy grail” of oil heating. If it’s done right, vaporization results in very low emissions of nitrogen oxides (NO