Chapter 15 (AIR CONDITIONING) Flashcards
How do you call the water vapor content of air?
B. Humidity
When air contains all of the water vapor it can hold, it is said to be
C. Saturated
What is the instrument used to register relative humidity?
A. Hygrometer
Humidity is a measure of which of the following?
A. Water Vapor Content
Air conditioning is the process of:
C. Maintaining the air at a required temperature and humidity
In an air-conditioning system, before the air is circulated to the required area, it is:
D. All of the above
The temperature at which water vapor in the atmosphere begins to condense is known as the:
B. Dew Point
Saturationg temperature is the same as:
A. Dew Point
When the bypass factor is B, the coil efficiency for sensible cooling of air is equal to:
B. 1-B
The psychrometric chart in air conditioning determines the
D. Moist Air Conditions
Which of the following is considered as comfort condition in air conditioning?
D. 20°C DBT, 60% RH
The drift loss in cooling towers is about:
C. 10-20%
Cooling towers are used for cooling water:
D. To be used for cooling the compressor
By which of the following processes heat mainly dissipates in cooling towers?
D. Evaporation
Which one is commonly used in liquid absorbent?
C. Ethylene Glycol
In sensible heating cooling following parameter remains unchanged
D. Humidity Ratio
Heating and dehumidification can be obtained simultaneously if air is passed through:
D. Any one of B and C
Dirt and foreign materials normally build-up on the side of the condenser tubes. To ensure adequate condenser capacity, a certain factor is used in calculating the overall heat transfer through the walls of the tubes including the heat transfer rate of the layers dirt and foreign materials. What is this factor?
C. Fouling Factor
The engineer was tested to design the air conditioning system for a ball room dance hall. Comsidering that this involve a lot of activity from its users, the engineer would design that will require:
A. Maximum Attainable Effective Temperature
What is the value of the Mach No. throat of the converging-diverging nozzle?
C. One
What do bodies at a temperature above absolute zero?
B. It emits Thermal Radiation
When air is saturated, the wet bulb depression is:
A. Zero
In a window air conditioning unit, which of the following is usually done by the owner
A. Semiannual cleaning or replacement of filters
Fan motors in air conditioning units usually have:
A. 2 or 3 speeds
Which of the following capacitors that can usually be found in an air conditioning unit?
D. All of these
Which of the following troubles commonly occurs inside an air conditioning unit?
D. All of these
The motor condition of an air conditioning unit can be checked with:
A. The continuity of light or with an ohmmeter
An air conditioning system wherein the entire systems are mounted in the cabinet:
A. Console Air Conditioners
The use of water to carry heat occupied spaces
A. Hydronic Heating System
The method of cooling which primarily used where ambient air temperatures are high and relative humidity is used:
A. Swamp Cooling
The other name for swamp cooling is
C. Wet Roof Cooling
Evaporative Condenser is used to cool
A. Condenser Vapor
A method of cooling which uses water as refrigerant. Pressure on the water surface is reduced to lower its boiling temperature.
A. Steam Jet Cooling
How should the window type air conditioning unit be placed?
B. Slant toward the outside of the home
The amount of CO can be determined by the color of Palladium Chloride. An amount of 30ppm to 70ppm will cause:
A. Slight Darkening
The term used to express the amount moisture in a given sample of air. It is compared with the amount of moisture in a given sample of air.
B. Relative Humidity
A dehumidifier is usually a smalk hermitic refrigerating system. It has both a condenser and an evaporator. Many older systems use R-12 or R-500. The newer units use:
A. R-134a
Palladium Chloride may be used to measure the presence of:
B. CO
The normal cut-out setting of a window unit thermostat is between:
A. 13°C to 16°C
Thermostat are used with most window units. They have differentials which vary between:
A. 2°C to 4°C
In an air conditioning unit, the thermostat fails. The unit did not start. How do you test the operation of the thermostat?
A. Cover the air outlet and air inlet with a cloth. The air will recirculate into the unit and the temperature will quickly drop to the cut out temperature.
Which of the following dehumidifier is often used to reheat the air after moisture is removed?
C. Condenser
Which of the following refrigerant is added sometimes to other refrigerant to improve oil circulation?
C. R-170 (Ethane)
A refrigeration that deals with producing temperature of -157°C or lower
D. Cryogenics
Measurement of a device’s ability to remove atmospheric air from test air.
A. Atmospheric Dust Spot Efficiency
A liquid mixture having constant maximum and minimum boiling points. Refrigerants comprising this mixture do not combine chemically, yet the mixture provides constant characteristics.
A. Azeotropic Mixture
Refrigerant in Group A1 (R-11). Chemical combination of carbon, chlorine, and fluorine.
A. Carrene
Which of the following refrigerants is popular in the industrial refrigerating system; also popularly absorption system of refrigerant.
A. R-717 (Ammonia)