Outdoor air supplied to replace exfiltration and exhaust air and air used to support the combustion process is known as

A four branch parallel circuit has 2 amps of current in one branch and 3 amps, 6 amps, and 7 amps in the other branches. The branch with the larger load is the ________ branch.

A thermistor start assist kit is used on:

What safety measures are used to prevent a dangerous increase in pressure in a hot water heating system?

A fuse or circuit breaker is sized so as to prevent an overload on the conductors it protects. Conductors and circuit breakers must be sized appropriately for the load that the circuit is intended to carry.

As the secondary air is decreased, the percentage of carbon dioxide in the flue gases increases, and the chance of producing carbon monoxide becomes greater.

Minimum economizer settings are established by ASHRAE standard 62 based on the ____ of the structure.

The net stack temperature on an oil fired furnace can be calculated by subtracting the air temperature around the furnace from the flue (stack) temperature.

The most commonly used seam in the sheet metal shop is the _____.

In HVAC, switches are normally wired