EPA, along with State and industry stakeholders, believes emissions testing using cord wood is important because it presents a more realistic picture of emissions from wood heaters in daily use. Manufacturers of wood burning devices who must meet the Final New Source Performance Standards (NSPS) for Residential Wood Heaters can test emissions using cord wood.

While not required, manufacturers choosing to test with cord wood need to have prior EPA approval.

Crib wood is a specified configuration and quality of dimensional lumber and spacers, usually cut 2”x4” or 4”x4” lumber Crib Woodthat is stapled together.  This configuration was intended to improve the repeatability of wood burning emissions test methods.

Cord wood

Firewood, also called cord wood, is what a typical homeowner uses, and is a more accurate measure of how a wood heater will perform in homes.

In the preamble to the NSPS, commenters overwhelmingly agreed that cord wood testing better represents real-world conditions, provides better information for consumers to choose the cleanest and most efficient heaters and that the EPA should encourage cord wood testing. Thus, the final regulation includes a cord wood alternative compliance option for Step 2 and allows voluntary, temporary EPA hangtags for devices tested with cord wood.