HVAC 1 Mod 5 Review Questions
10
5lb of water heated to raise the temperature 2*F requires how many BTU's?
discharge pressure
A TXV regulates the flow of refrigerant to the evaporator to maintain a consistent _______.
reciprocating compressor
A compressor with a piston that travels back and forth in a cylinder is a _______.
from a higher pressure to a lower pressure
A gas or a liquid always flows _____.
hygroscopic
A substance that attracts and absorbs moisture from the air is referred to as being _____.
changing it's resistance to electrical flow
A thermistor responds to temperature changes by _____.
counterflow towers
Forced-draft cooling towers in which the air flow is forced up from the bottom as water trickles down are called ______.
rose
HFC-410A refrigerant comes in a disposable container that is painted ___.
72*F(22*C)
If a gas is superheated 15*F(8.3*C) to a temperature of 87*F(31*C), we can determine that its boiling point is _____.
evaporator
In a refrigerant circuit, the low pressure, low temperature liquid is converted into a low-pressure, low-temperature vapor in the _____.
compressor
Ina refrigeration system, the low-pressure, low-temperature vapor is converted into high-pressure, high-temperature vapor by the _____.
50
OSHA establishes the maximum exposure to ammonia vapors at 5 minutes to a concentration of how many parts per million(ppm)?
time clock
One clear example of a secondary control ____.
centrifugal
Reciprocating compressors can be found in any of the following configurations except _____.
can be measured by a thermometer
Sensible heat is heat that __________.
after all of a solid changes to a liquid
Super heat can be gained _______.
212
The Fahrenheit scale is based on the temperature water boils at sea level, which is ___*F.
accumulator
The accessory found only in the refrigeration circuit suction line is the _____.
size of the opening and the pressure applied
The amount of refrigerant flow through a fixed-orifice metering device is dependent upon the _____.
as the pressure is decreased
The boiling temperature of a liquid is decreased ____.
the fluorocarbon always has fluorine in it, but not all halocarbons do
The difference between a halocarbon and a fluorocarbon refrigerant is that ______.
HFCs
The fluorocarbon refrigerants that are least harmful tot the ozone layer are the ______.
inlet of the comprpessor
The low side of the refrigeration system include the _____.
remove heat from the refrigerant
The main purpose of a condenser is ____.
transfer heat into the refrigerant
The main purpose of an evaporator _____.
maintain a predetermined liquid level
The metering device for a flooded evaporator is designed to ____.
-
The operation of a double-suction riser depends on ______.
conduction
The transfer of heat from one object to another by direct contact is called ____.
a fusible plug responds to high pressures; a rupture disk responds to high temperatures
What is the difference between a fusible plug and a rupture dish?
grey with yellow shoulders
What is the required color code for refrigerant recovery cylinders?
subcooled
When the temperature of a liquid refrigerant is below its condensing temperature, the liquid is _______.
liquid line
Which primary refrigerant line is considered the least critical in its layout and installation?
receiver
Which refrigerant circuit accessory provides a place to store the system refrigerant charge during service procedures or prolonged shut downs on larger systems?
infrared heating systems
Which type of heating unit or system is based on radiation?
14.7
Zero gauge pressure (0 psig) corresponds on the absolute scale to ____ psia.
ammonia
_______ is slightly more efficient at transferring heat that halocarbon refrigerants.
