What is the purpose of excess air in furnace combustion?
A) Excess air is used for creating a high-fire second stage of combustion.
B) Excess air improves the draft efficiency by raising the combustion gas temperature.
C) Excess air ensures that all the gas is burned by making sure there is plenty of oxygen available.
D) Excess air ensures that the heat exchanger does not overheat.
[Ques. 2] The pump should be located between the tower and the chiller so that:
A) The water is pulled from the tower and pushed through the condenser.
B) The inlet for the sump can be piped to both the sump and the condenser.
C) The water is pulled from the condenser and pushed into the tower.
D) The inlet for the pump is above the water level in the sump.
[Ques. 3] What types of humidifiers work best with heat pump systems?
A) Steam humidifiers B) Wetted element
C) Plate humidifiers D) Water spray misters
[Ques. 4] Combustion air for gas appliances should be:
A) 10 cu ft of combustion air per 1,000 BTU of firing rate.
B) Recycled by piping the vent gases back into the combustion air intake.
C) 1 cu ft of combustion air for every cubic foot of gas.
D) 14 to 15 cu ft of combustion air per 1,000 BTU of firing rate.
[Ques. 5] Where are unit ventilator fan coil units installed in schools?
A) In the school mechanical room B) Below window level in each classroom
C) On the roof above each classroom D) Outside each classroom on a concrete pad
Quick Reply
