Method of Test for Tracer Gas Test of an Outdoor Furnace Designed for Installation Without a Flue Pipe.
Method of Test for Tracer Gas Test of an Outdoor Furnace
Designed for Installation Without a Flue Pipe.
Liu, S. T.; Kelly, G. E.
NISTIR 6257; 20 p. November 1998.
Available from: National Technical Information Service
furnaces; flues; pipes; annual fuel utilization;
ANSI/ASHRAE Standard 103; DOE test procedure;
efficiency; flue gas measuring location; flue pipe;
gas-fired furnace; induced draft furnace; outdoor
installation; power burner draft factor; tracer gas test
An induced draft, gas-fired furnace originally designed
for outdoor installation without a flue pipe was tested
by the tracer gas method to determine its off-cycle
power burner draft factor. When conducting the tracer
gas test, the lack of the needed space for sensor
installations and for shielding the sensors from ambient
air disturbance creates an accuracy problem for the
manufacturers and the testing agency to properly conduct
the test. This report is to determine the feasibility of
attaching a short flue pipe to the outdoor furnace
during the optional tracer gas test to facilitate test
measurement without significantly increasing the
measured power burner draft factor due to the stack
action of the added flue pipe. The results showed that
it is possible to conduct the tracer gas test with a
short flue pipe of less than 0.3 m (12 in.) without
changing the calculated results for the value of Annual
Fuel Utilization Efficiency (AFUE). Therefore, it is
recommended that a short flue pipe, between 0.2 to 0.3 m
(8 in. to 12 in) in length, be allowed in the Department
of Energy (DOE) furnace test procedure during the
optional tracer gas test for an outdoor furnace designed
for installation without a flue pipe.