[ILM] 102D

Question 1

wet thermometer gives

Answer 1

a wet bulb temperature

Question 2

if the air is perfectly dry, then that air sample is said to have

Answer 2

zero enthalpy

Question 3

sublimation

Answer 3

the phase change from a solid directly to a vapour without passing through the liquid state

Question 4

Dew Point(DP)

Answer 4

an air condition in which dry and wet bulb temperatures are the same

Question 5

most people are comfortable in a relative humidity ranging between

Answer 5

30-60%

Question 6

how many grains in 1lb of water

Answer 6

7000 grains

Question 7

the higher the specific density of air,

Answer 7

the greater the horsepower rate the fan and its driving motor require to move the heavier air

Question 8

Volatile Organic Compounds

Answer 8

emit toxic gases

VOC

Question 9

wet air is lighter than dry air

T or F

Answer 9

True

Question 10

Standard air

Answer 10

Temp: 68F
Press: 14.7 psia
Density: 0.075 lb/ft3

Question 11

Air transfers heat in 3 ways:

Answer 11

1. Radiation
2. Conduction
3. Convection

Question 12

Radiation

Answer 12

gas only

Question 13

Convection

Answer 13

gas or liquid

Question 14

Conduction

Answer 14

solid

Question 15

pressure is

Answer 15

the amount of force applied per unit area

Question 16

weight of 1psi

Answer 16

is similar to the weight of approx. 6897 five-dollar-bills

Question 17

1 psig ==

0 psia == -14.7psig

Answer 17

2.04”hgv

29.92”hgv

Question 18

Total pressure - Static pressure ==

Answer 18

Velocity pressure

Question 19

velocity means both

Answer 19

speed & direction

Question 20

typical AC unit cfm

typical Heat Pump unit cfm

Answer 20

400 cfm/ton

450 cfm/ton

Question 21

MERV stands for

the higher the MERV,

Answer 21

Minimum Efficiency Reporting Value

the more efficient the filter

Question 22

MERV rating

Answer 22

1-20

Question 23

MERV ratings

1. basic residential furnace
2. good residential, basic commercial
3. good commercial
4. hospital surgical areas

Answer 23

1. 1-4
2. 5-9
3. 10-14
4. 15-17

Question 24

pitot tube is

Answer 24

an air pressure measuring device

Question 25

anemometer

Answer 25

measures air velocity

Question 26

velometer

Answer 26

an airflow meter that takes readings in feet per minute and is used for taking direct readings of air velocities

Question 27

Determine the velocity for 0.04" wc

Answer 27

v = 4005 x root 0.04 = 4005 x 0.2 = 801 fpm

Question 28

Determine air volume flow rate

Answer 28

cfm = fpm x (A in inches / 144 in2/ft2)

Question 29

Find the amount of heat (total heat transfer)

Answer 29

Q = 4.5 x cfm x delta(h) delta(h) = change in btu

Question 30

Find the amount of sensible heat (sensible heat transfer)

Answer 30

Q = 1.08 x cfm x delta(f) delta(f) = change in temperature