February 03, 2010
The Indiana Department of Environmental Management has begun the process of writing new rules to regulate outdoor hydronic heaters, also known as outdoor wood furnaces, outdoor wood boilers, wood heaters and water stoves. The units are used to heat homes and businesses and also can be used to heat swimming pools and hot tubs.
IDEM is considering rules that would set requirements for smoke stack height and emissions standards for units installed after the rule is effective. The agency also is considering additional operational rules and fuel restrictions.
According the IDEM Web site, an initial public comment period for the rulemaking on the units was published on Dec. 5, 2005, with a deadline to comment set at Jan. 3, 2006. Due to several requests, an extension was granted that set the deadline for March 3, 2006.
According to IDEM descriptions, outdoor wood boilers are free-standing, wood-burning appliances that heat water, which is then pumped underground to provide heat to a structure. An outdoor wood furnace also can be used to provide hot water year-round.
IDEM also claims that larger capacity, low stack heights, design differences, operating conditions and lower operating temperatures cause more intense smoking and smoldering conditions nearer to ground level than in other woodburning devices. The agency also claims that those factors have led residents to complain to IDEM about certain outdoor wood boilers.
According to IDEM, stack heights on outdoor wood boilers are typically eight to 10 feet above ground level. Chimneys on homes are almost always above the roof line and are typically 20 to 30 feet above ground level. The lower stack heights decrease the opportunity for wood smoke to disperse, to some extent, in the surrounding air before affecting nearby individuals and residences at ground level. And IDEM states that the basic design of outdoor wood boilers causes fuel to burn incompletely, or smolder, which can result in thick smoke and high particulate emissions.
Mailed comments on the new rules should be addressed to:
#05-332 (APCB) Outdoor wood boilers
Sean Gorman Mail Code 61-50
c/o Administrative Assistant
Rules Development Section
Office of Air Quality
Indiana Department of Environmental Management
100 N. Senate Ave.
Indianapolis, IN 46204
IDEM will accept comments on the issue until Feb. 22.