CSA 3.7-2017 pdf free download

CSA 3.7-2017 pdf free download.Non-recirculating direct gas-fired heating and forced ventilation appliances for commercial and industrial application.
The air inlet to the heater shall be gradually restricted until the air flow sensing system acts to shut off the main burner gas. The high temperature limit control system shall not function to shut off the gas during this test. The operating temperature control system shall shut off or modulate the main burner gas so the outlet air temperature does not exceed 160 F (71 C) or the activation point of the high temperature limit control system, whichever is less.
If the heater is equipped with variable or adjustable profile plates, the above test shall be repeated at the manufacturer’s specified minimum rated air throughput.
5.9 Combustion
5.9.1
Combustion tests shall be conducted with the heater adjusted to operate at the following conditions.
a) Manufacturer’s specified maximum rated air throughput, minimum external static pressure, and maximum temperature rise.
The air velocity or pressure drop across the burner shall be maintained at the air flow sensing system trip points, including the worst-case tolerance, of Clauses 5.7.1 and 5.7.2 (or maximum possible throughput for designs that do not incorporate a high air flow sensing system) for each temperature rise specified in Clause 5.9.2 by adjusting the fan speed or changing the profile plate opening, as applicable.
b) Manufacturer’s specified minimum rated air throughput, maintaining the air flow sensing system trip point including the worst-case tolerance of Clause 5.7.1, minimum external static pressure for each temperature rise specified in Clause 5.9.2 by adjusting the fan speed or changing the profile plate opening, as applicable.
c) On heaters furnished with profile plate(s) or bypass damper(s), the manufacturer’s specified minimum rated air throughput and minimum external static pressure. The air velocity or pressure drop across the burner shall be maintained at the air flow sensing system trip point including the worst-case tolerance of Clause 5.7.2 for each temperature rise specified in Clause 5.9.2 by adjusting the fan speed or changing the profile plate opening, as applicable.
d) The resulting air throughput starting with the manufacturer’s specified maximum rated air throughput and minimum external static pressure for each of the damper positions identified in Clause 5.7.3. The air velocity or pressure drop across the burner shall be maintained at the air flow sensing system point obtained during the conduct of Clause 5.7.3 for each temperature rise specified In Clause 5.9.2 by adjusting the fan speed or changing the profile plate opening, as applicable.
e) On heaters equipped with profile plate damper(s) or bypass damper(s), the test conditions of Clause 5.9.1 a) shall be re-established at the temperature rise point(s) where the CO results were found to be the highest.CSA 3.7-2017 pdf free download.