Light Commercial

Question 1

Parallel compressors are piped into a system in such a manner that

Answer 1

The discharge lines are connected to a common manifold

The suction lines are connected to a common manifold

Question 2

An advantage of the parallel compressor systems would be

Answer 2

Load matching
Higher efficiency
Less compressor cycling

Question 3

An optional arrangement added to a roof top air conditioning system which has a motorized damper and opens when the room thermostat calls for cooling and outdoor temperature and humidity conditions are met is called

Answer 3

An economizer

Question 4

Roof-top air conditioners typically are mounted on top of a roof curb to help provide a leak proof connection to the roof. The roof curb is generally ____________ high.

Answer 4

12-15 inches

Question 5

Many roof top heating/air conditioning systems are 2-stage heating or 2-stage cooling or both. The primary purpose for this is

Answer 5

To allow for fluctuating loads

Question 6

To maintain operating effectiveness and performance the air pressure in a building should be

Answer 6

Slightly positive to the outdoor pressure

Question 7

Air brought into a building to replace ventilated air leaving the building is called ________

Answer 7

Make-up air

Question 8

Some applications such as hospital rooms require

Answer 8

100% make-up air

Question 9

The most common method of indoor air odor control is

Answer 9

Dilution with ventilation air

Question 10

If more air is exhausted through ventilation than is made-up from fresh air inlets the building is considered

Answer 10

Negatively pressured

Question 11

In kitchens where appliances may add a considerable amount of both latent and sensible heat, the heating and cooling load can be reduced by the proper installation and use of_________

Answer 11

Exhaust hoods

Question 12

Correct installation and use of bathroom exhaust fans can greatly reduce the risk of

Answer 12

Indoor humidity issues

Question 13

Proper ventilation in modern mechanical rooms is important because the refrigerant leaked from a system

Answer 13

Can cause asphyxiation

Question 14

The primary purpose(s) for the use of a Variable Air Volume (VAV) system is to gain operating efficiency by

Answer 14

Offering building zone control
Reducing the indoor blower RPM
Capitalizing on passive solar gains

Question 15

The constant air volume system is less efficient than a variable air volume system because

Answer 15

The system always runs in the maximum cooling position

Question 16

When “zoning” a building for the purpose of climate control, zones are generally divided into areas by

Answer 16

Floors (1st floor, 2nd floor)
Exposure (north side, south side etc.)
Occupancy (number of people, type of activity)

Question 17

When working on an upper floor or a roof top of a building the top of the ladder should extend above the top edge of the roof by at least

Answer 17

3 feet

Question 18

When gas pipe is installed across a roof the pipe must be

Answer 18

Supported and fastened

Question 19

According to OSHA falls from ________________ are one of the leading causes of occupational fatalities and injuries.

Answer 19

Ladders

Question 20

OSHA recommends _______________ when climbing a ladder

Answer 20

Maintain a “3-point” contact with the ladder at all times

Question 21

Design specifications for “Suspended Personnel Platforms” require the support platform rating be at least ______________ the maximum intended load.

Answer 21

5 times