HVAC Theory Final Flashcards
Which is a two pipe hot gas defrost system?
Reverse Flow Hot Gas Defrost.
How many pipes is a conventional flow hot gas system?
Three pipes.
How is electric defrost usually terminated?
By time.
Which is evaporative condenser is usually found in a large industrial ammonia system?
Shell and tube.
Where are static condensers found>
Residential refrigerators and upright freezers.
What is an advantage of cool gas reverse flow defrost?
Less thermal shock to the evap. Lasts longer.
The use of a liquid chemical to absorb the vapor of another chemical is what?
The absorbtion method.
Which law states absolute temp and volume change proportionally while the pressure remains constant?
Charles Law.
Which law states that the pressures are equal in all directions?
Pascals law.
Which is the law of constant temperature?
Boyle’s law.
Does a high CoP indicate a more efficient system?
Yes.
A reduction in diameter will do what to the flow through it?
Increase velocity pressure, and decrease static pressure.
Evaporators with a higher TD usually..
Tend to have a greater capacity, provide a lower R/H, and require defrosting more often.
Evaporators with a lower TD usually..
Tend to have a lower capacity, provide a higher R/H, and require defrosting less often.
