To: nehearth@bigfoot.com, info@firespaces.com, staywarm@tempcast.com, Heikki.vauhkonen@tulikivi.fl, crouchpa@ix.netcom.com, Jerry Frisch <frischro@premier1.net>, tuliaha@adiglobal.com, Mike VanBuren <vanburen@hearthassociation.org>, Charles Clark <clark@bia.org>

Subject: Clearance language suggestion

Cc:

 Here's an idea about clearance language - please feel free to critique, or preferably, to improve or offer alternate suggestions:

 Jerry Frisch faxed today with comments, which are posted on MHA's IBC page:

 He related his experience with Swedish heaters, which in his opinion need a clearance of around 12". Let's assume for a second that that is correct. If we assume, for the sake of argument, that a Swedish heater has a firebox thickness of 5", then, using an 8" firebox with 4" clearance as a second data point, we could assume a linear relationship and extrapolate a chart thus:

Figure 1

 For soapstone, we could have a simple multiplier, such a X 2

 If this approach is deemed reasonable, then it simply remains to establish the actual slope of the graph, and the soapstone multiplier, preferably from testing. I would propose that we agree the final arbiter to be the ASTM subcommittee - this way, it will have to pass the test of outside professional opinion.

 Norbert