Unit 36: Lab Work - Air-Conditioning System Refrigerants and Component

Slant coils for downflow application are designed with a coil slant of usually

60

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

Both a and c.

Appearance is a major drawback with what type of air-conditioning equipment?

Ductless split systems.

After being threaded many times, the screw holes in condenser cabinets may become oversized; if so, replace the screws with new ones of the same size.

False

List three common types of compressors that are used in air-conditioning systems Reciprocating, Rotary, Scroll.

False

On a package air-conditioning system, which refrigerant lines must be field-installed?

No lines need to be field-installed.

If a structure has no attic, there should be sufficient insulation in the roof to minimize the heat gain in the occupied space.

True

Manufacturers are increasing the physical size of the condenser coil to increase heat transfer rate.

True

List the four major components of an air-conditioning system.

[Compressor condenser metering device Evaporator]

When an "A" coil is used in a horizontal application, the coil is laid on its side and a special __________ pan is required.

condensate

The air temperature of the air off an evaporative cooler is ____.

cooler than the entering air

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

copper tube-aluminum fin

In rotary compressors, the motor is cooled by ____.

discharge gas from the compressor

The return duct portion of an air handling system never needs to be insulated.

false

High-efficiency condensers ____.

have more surface area than standard condensers

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

heat from the radiation from the sun

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 ____.

humidity

The package air-conditioning system is ____ than the split system because it is completely factory assembled and charged with refrigerant.

more efficient

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 south

Three types of expansion devices are used in residential air conditioning systems. They are TXV, capillary tube, and

orifice

A dirty condenser coil can lead to ____.

reduced efficiency

A compressor that uses a stationary vane is the ______ type.

rotary

There are three kinds of attic ventilation: power, natural, and

solar powered

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

stainless steel

More than one evaporator coil circuit is used when ____.

there would be excessive refrigerant pressure drop in the coil circuit

Air-conditioning equipment will perform at its best efficiency when running at full load.

true

If a residential split air-conditioning system has a compressor equipped with a start capacitor and relay, it is probably using a thermostatic expansion valve as a metering device.

true

The moisture content of the air in different locations of the country must be taken into account when selecting air-conditioning equipment.

true

The supply duct portion of an air handling system needs to be insulated when run through an unconditioned space.

true