Environmental Engineering Reference
In-Depth Information
TABLE 9.6
Gas and Oil Fired Boilers - Minimum Efficiency Requirements
Subcategory or
Rating
Condition
Size Category
(Input)
Equipment Type
Eficiency
Test Procedure
Boilers, hot
water
Gas fired,
<87.9 kW
89% AFUE
10 CFR Part 430
.87.9 kW and
<732.7 kW
89% Et
10 CFR Part 431
.732.7 kW
91% Ec
Oil fired
<87.9 kW
89% AFUE
10 CFR Part 430
.87.9 kW and
<732.7 kW
89% Et
10 CFR Part 431
.732.7 kW
91% Ec
Boilers, steam
Gas fired,
<87.9 kW
75% AFUE
10 CFR Part 430
Gas fired all,
except natural
draft
.87.9 kW
and <732.7 kW
79% Et
10 CFR Part 431
.732.7 kW
79% Et
Gas fired,
natural draft
.87.9 kW and
<732.7 kW
77% Et
.732.7 kW
77% Et
Oil fired
<87.9 kW
80% Et
10 CFR Part 430
.87.9 kW and
<732.7 kW
81% Et
10 CFR Part 431
.732.7 kW
81% Et
Ec = combustion efficiency (100% less flue losses).
Note:
Units shall also include an interrupted or intermittent ignition device, have jacket losses
not exceeding 0.75% of the input rating and have either power venting or flue damper.
A vent damper is an acceptable alternative to the fuel damper for those furnaces where
combustion air is drawn from the
conditioned space
.
As of August 8, 2008, according to the Energy Policy Act of 2005, units shall also
include an interrupted or intermittent ignition devices and have either power vent-
ing or automatic flue dampers. A vent damper is an acceptable alternative to a flue
damper for those unit heaters where combustion air is drawn from the
conditioned
space
.
Ducts and Plenum Leakage
For duct sealing, Seal Level A shall be used. This requirement supersedes
the requirements in Section 5.3.4.6.2 of EEECBC.
Economisers
Systems shall have economisers as specified in Table 9.8 [6] and high-limit
controls as specified in Table 9.9 [6]. Rooftop units with a capacity of less
than 60,000 Btu/h (18 kW) shall have two stages of capacity control, with the
first stage used for cooling with the economiser and the second stage to add
mechanical cooling.
