Unit Heaters


Unit heaters are a type of commercial heating product that is typically used to heat open commercial spaces such as factories, warehouses, and garages; they are usually hung from the ceiling.


The current standards for unit heaters took effect in 2008. The standards, which were based on standards that had previously been adopted by several states, are prescriptive requirements that require that unit heaters be equipped with an intermittent ignition device and have either power venting or an automatic flue damper.


Typical gas-fired unit heaters generally have a thermal efficiency of about 80%, which means that 20% of the energy is wasted. Condensing unit heaters extract additional heat by condensing the water vapor in the flue gases and achieve thermal efficiencies of 90% or higher.


Federal Date States
2008 AZ Standard Effective *
2008 OR Standard Effective *
1st Federal Standard Effective 2008
2007 NJ Standard Effective
2007 WA Standard Effective
2007 RI Standard Effective
2006 CT Standard Effective
2006 CA Standard Effective
2005 MD Standard Effective
1st Federal Standard Adopted (Congress) 2005
EPACT Initial Federal Legislation Enacted 2005
2005 WA Standard Adopted
2005 NJ Standard Adopted
2005 AZ Standard Adopted
2005 RI Standard Adopted
2005 OR Standard Adopted
2005 NY Standard Adopted
2004 CA Standard Adopted
2004 CT Standard Adopted
2004 MD Standard Adopted

* State standard never went into effect due to preemption by federal standard.

States not showing an effective date have an ongoing rulemaking process to determine standards.

Timeline reflects state standards from 2001 to present; federal standards from inception to present.