Principles Of Automatic Heating And Cooling Controls

Front 1

heat is thought of as

Back 1

energy in transit

Front 2

heating is

Back 2

higher temp object to lower temp object

Front 3

cold is a relative lack of heat meaning?

Back 3

its a perspective ice is colder than water but water can still be cold

Front 4

qauntitys of heat? are

Back 4

energy=joule in the si system

and btu in imperial

power=watt in the si system and btuh in the imperial system

Hint 4

energy is one power is another

Front 5

btu is described as?

Back 5

required heat to change 1lb water to 1°F or 250 calories or 1055 joules

Front 6

typical heating system ranges?

Back 6

80k-100k btu/h or 23.4-29.3 kW

Front 7

cooling systems are rating by

Back 7

output

Front 8

cooling systems in si and imperial would be typically what in resi

Back 8

7.5 tonne•cal/h in imperial 2.5 ton

Front 9

conduction is

Back 9

heat transferred through solids

heating one part of a solid heat eventually transfers to the cooler part

Front 10

convection is

Back 10

transfer by fluids meaning air or water

basically heat rises then you can replace it with cold which falls

Front 11

radiation is

Back 11

is electromagnetic wave motion

like the sun

the greater the heat diffrence the faster the transfer

Front 12

human comfort depends on

Back 12

temperature humidity air movement and radiation

Front 13

temperatures optimum comfort

Back 13

20°C

Front 14

humidity comfort requires moisture from body evaporation at the right pace what is optimum for this?

Back 14

40% humidity

Front 15

air movement dose what to comfort

Back 15

removes heat and moisture quickly causing discomfort

Front 16

radiation can cause discomfort because

Back 16

your body radiates heat to cold objects

Front 17

cold 20?

Back 17

when temperature is correct but humidity is wrong ***** with your head temp

or if walls are cold or air velocity

Front 18

automatic control systems are

Back 18

operating controllers or control devices

Front 19

operating controller is

Back 19

thermostat for example

Front 20

control device is a

Back 20

gas valve for example

Front 21

automatic controls are for?

Back 21

comfort safety economy and convenience

Front 22

closed loop control can be switched by hand

Back 22

no it need to be all automatic

Front 23

main burners

Back 23

are the ignition system and gas valve

they heat the heat exchanger

Front 24

the fan or blower

Back 24

draws air and blow hot air off the heat exchanger

Front 25

load devices?

Back 25

gas valves relays motors igniters are all examples and respond from controlling devices

Front 26

controlling and sensing devices are?

Back 26

provide feedback to a load device

they react to changes

thermostat humidistats and limit switches and pressure switches

flame rods, sail switches are examples

Front 27

the heat exchanger is?

Back 27

a metal inclosure that CONDUCTS heat which RADIATES into cleanair

Front 28

the flue also called ..... dose what

Back 28

also called a stack carries gases from the fuel out the heat exchanger to the chimney

Front 29

filters do what

Back 29

filter air and prevent burning dust on the heat exchanger

Front 30

the supply plenum

Back 30

sheet metal box collect heated air and equally distributes pressure

Front 31

what carries the air

Back 31

ducts to the registers

Front 32

power supplys are 24v or 120v

Back 32

**** yah dude i love it

Front 33

thermostat is a

Back 33

temperature acutuated sensor

and a temperature sensing device

Front 34

high limit is

Back 34

a gas cut off to prevent heat dmg

Front 35

fan control switches sense air in the

Back 35

plenum with a relay or directly

Front 36

read page 10 of module

Back 36

please its alot just review it jesus mitch

Front 37

thc is

Back 37

thermocouple

Front 38

thp is

Back 38

thermopile

Front 39

pp is

Back 39

power pile

Front 40

in a schematic transformed side are labeled what instead on l1 l2

Back 40

x1 x2

Front 41

controlled and load devices go on what side? on a schematic

Back 41

controlled on the left load on right

Front 42

all devices on a schematic require?

Back 42

labels to identify

Front 43

review schematic guide on pgs 12 and 13

Back 43

pleaaase you fuck

Front 44

load device are also known as

Back 44

actuators

Front 45

what section deals with cooling and heating equipment

Back 45

there isnt one its mentioned but no section

Front 46

26-806

Back 46

gas furnace needs its own branch

Front 47

larger heating equipment needs to be solely the only thing one the branch

Back 47

t section 26-808

Front 48

26-802

Back 48

mech protection for wires in furnace

Front 49

you need a disconect unless

Back 49

the panel suits rule 26-806

Front 50

a/c units need to be disconnected

Back 50

with a switch in sight

Front 51

a heating thermostat symbol on a schematic should be shown

Back 51

heating is normally closed and cooling is normally open