United States Stove Company KP5522-P, Manual

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the position(s) as needed to achieve a burn rate that is ≤ 50% of the maximum burn rate.” Table 1
of ASTM E2779-10 also notes that th
e Medium Burn Rate Category test must be ≤ 50% of the
maximum burn rate. The memorandum states that this is incorrect as it assumes that zero is the
other bound for determining half of the maximum burn rate, and that the correct approach in
determining the Medium Burn Rate Category should be at a level below 50% of the span
between the Maximum Burn Rate and the Low Burn Rate (a non-zero value).
We have reviewed your request and agree that the Medium Burn Rate Category should be
defined as less than 50% of the span between the high and low burn rates. Meaning that the
Medium Burn Rate Category should be at a level below 50% of the span between the Maximum
Burn Rate and the Low Burn Rate (a non-zero value).
Based on the information provided and with the caveats set forth below, we are approving your
request for an alternative methodology used when calculating the Medium Burn Rate Category
to conduct certification testing as required by Subpart AAA, section 60.534(a)(1)(i) on pellet
heaters. This approval is based on the understanding that the Medium Burn Rate Category is
defined as less than 50% of the span between the high and low burn rates. Additionally, this
approval is based on the understanding that the lowest heat output (Btu/hr) setting available to
the user, and corresponds to the lowest burn rate to be evaluated during certification testing; this
is consistent with Subpart AAA, section 60.534(a)(1), which states: “The burn rate for the low
burn category must be no greater than the rate that an operator can achieve in home use and no
greater than is advertised by the manufacturer or retailer.”
With this Alternate Test Method, the following changes to ASTM E2779-10 must be followed
for certification testing:
1. Medium Burn Rate Category burn rate is defined as:
Nomenclature:
Max
= Maximum burn rate (kg/h)
Min = Minimum burn rate (kg/h)
𝑀𝑀𝑀𝑀𝑀𝑀+𝑀𝑀𝑀𝑀𝑀𝑀
2
Eq.1
All other requirements of ASTM E-2779-10 must be followed during the testing, and all
requirements of 40 CFR part 60, Subpart AAA must be satisfied as described in your test report.
A copy of this letter must be included in each certification test report where this alternative test
method is utilized.
Because this alternative method may be of use to others, we feel that it is reasonable that this
approval be broadly applicable to all pellet heaters tested in accordance with ASTM E2779-10
“Standard Test Method for Determining Particulate Matter Emissions from Pellet Heaters” and
subject to the requirements of §60.534(a)(1)(i) of Subpart AAA. For this reason, we will post this