Oklahoma
Technical
College
HVAC
Program
100

Sensible heat is defined as what?

Heat that can be measured

100

Specific heat is defined as what?

The amount of heat required to raise 1lb of a substance 1 degree. 

100

What is a BTU?

The amount of heat required to raise 1lb of water 1 degree. 

100

Latent heat is defined as what?

Heat used to cause a change of state.

100

One ton of refrigeration is what?

12,000 Btu/hr

200

A room thermostat should be mounted at how many feet from the floor? (This is code)

5 feet from the floor

200

To provide proper oil return to the compressor, The suction line must be pitched toward what?

The compressor

200

What is the purpose of the external equalizer on a TXV?

To offset for the pressure drop across the evaporator.

200

What would be the minimum bending radius on 1" soft copper tubing?

5"

200

What is the heating value of natural gas? 

1,000 Btu/cu ft

300

The purpose of a fan control is to what?

Start and stop the fan motor. 

300

What does a high limit control do?

De-energizes the gas firing circuit upon high bonnet temperatures. 

300

An unconfined space is what?

A space whose volume is greater than 50 cu ft / 1,000 btu of total input of all gas fired appliances.

300

What is the total free area of a 15" x 24" combustion air opening used with a metal grill with an unknown free area?

270 sq in.

300

A confined space is what?

A space whose volume is less than 50 cu ft / 1,000 btu/h of total input of all gas fired appliances. 

400

What is the purpose of the reversing valve on an air to air heat pump?

It changes the flow of the refrigerant making the indoor coil the outdoor coil and the outdoor coil the indoor coil. 

400

Which of the following is connected to the top port of a reversing valve?

The discharge line of the compressor. 

400

One horsepower is the same as what?

746 Watts.

400

One watt equals what?

3,412 Btu's

400

An open run winding will be indicated by which of the following using an ohmmeter?

Infinite ohms from run to start.

500

A grounded condition found with an ohmmeter on a compressor motor will be indicated by which of the following?

A zero reading from any terminal to compressor housing. 

500
How is a heat anticipator wired with the operating contacts?

Series

500

How is a cooling anticipator wired with the operating contacts?

parallel

500

What is the purpose of a solenoid valve?

It controls the flow of a fluid.

500

Which of the following is the correct method for fastening sheet metal joints?

Steel metal screws.