Exam 50: Commercial Rooftop, Packaged, Variable Refrigerant Flow, and Variable Air Volume Systems

The term enthalpy refers to the total heat content in the air, which accounts for both the temperature (sensible heat portion) and the moisture content (latent heat portion) of the air.

The unit's location should be carefully selected so the system's operation is not adversely affected by air being able to ____ the condenser coil.

By utilizing a strategy called demand control ventilation, DCV, the amount of outside air being brought into the building can be varied based on the actual occupancy level in the structure.

If the curb is mounted as part of a new construction process, it can be assembled and installed as soon as the ____ support system is in place.

By tapping his fist on his ____, the crew member is telling the crane operator to use the main hoist.

____ are intended to help provide the correct amount of ventilation and also help reduce cooling costs by allowing outside air to be introduced to the conditioned space when conditions are correct.

How do variable refrigerant flow (VRF) systems modulate the volume of refrigerant that is pumped through the system?

The economizer is able to increase or decrease the amount of outside air that is brought into the structure with two ____.

The rooftop unit houses the fans and blowers that move air through the heating and cooling portions of the unit but not through the condenser.

Although packaged air-conditioning equipment comes precharged with refrigerant and no field piping must be done, the installation of a rooftop package unit involves many steps and can be very dangerous.

Explain the purpose of the relief fan.

The amount of refrigerant indicated on the ____ is the total refrigerant charge for the unit, not simply a holding charge as in the case of a split-type system.

Some roofs are bonded, which are roofs that carry a written warranty or insurance policy that protects the building owner in the event damage from leaks occurs.

The water coil in a dry cooler can contain 100% water or can be a mix of water with  ____________________.

Many rooftop package units are equipped with multiple ____________________ fans.