unit 36

The total heat content of infiltrated air of the same dry-bulb temperature may vary from one part of the country to another because of the difference in ____.

• solar load

• sensible heat

• humidity

• convection currents

A homeowner plans to build a house out in Las Vegas, Nevada, in the middle of the desert. It would be in his/her best interest to lower the 'solar load,' to locate most of the windows on the ____ sides of the house.

• north and east

• east and west

• north and south

• south and west

The solar load on a structure is the heat gain resulting from the ____.

• heat from the surrounding air conducted through the materials of the structure

• air infiltration

• heat from the radiation from the sun

• dry-bulb inside the structure

More than one evaporator coil circuit is used when ____.

• the evaporator is located outside the conditioned area

• there would be excessive refrigerant pressure drop in the coil circuit

• a distributor would not be practical

• a slant coil is at an angle more than 60°

A popular material combination used in air-conditioning evaporators and condensers is ___.

• copper tube-stainless steel fin

• copper tube-copper fin

• copper tube-aluminum fin

• stainless steel tube-aluminum fin

In reciprocating compressors used in air conditioning, the motor is mainly cooled by ____.

• air over the shell of the assembly

• none

• suction gas returning to the compressor

• both

In rotary compressors, the motor is cooled by ___.

• air over the shell of the assembly

• discharge gas from the compressor

• suction gas returning to the compressor

• liquid refrigerant by-passed from the liquid line

A dirty condenser coil can lead to ___.

• increased efficiency

• reduced efficiency

• reduced head pressure

• increased subcooling

High-efficiency condensers ___.

• can withstand higher pressures than standard condensers

• have more surface area than standard condensers

• have stainless steel coils

• are located in separate cabinets

When exposed to salt air, ___ should be used for the screws to secure the sheet metal of cabinets of air conditioning equipment.

• copper

• stainless steel

• iron

• tin