102_Air Conditioning Basics

8/13/2019 102_Air Conditioning Basics

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Basic Concepts of Air

Conditioning

Prepared exclusively

forCOACH LEATHERWARE


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Slide 1

SOURCE OFCOOL AIR

COIL

HEAT

COIL COOLAIR


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Slide 2

TYPICAL ALL-AIR SYSTEM

S.A. DUCT

HEAT

COIL COOLAIR

S.A.FAN


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Slide 3


S.A. DUCT

HEAT

COIL COOLAIR

S.A.TERMINAL

S.A.FAN


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Slide 4


S.A. DUCT

HEAT

COIL

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

WARM AIR


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Slide 5


R.A DUCT

S.A. DUCT

HEAT

COIL

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN


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Slide 6


R.A DUCT

S.A. DUCT

HEAT

COIL

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 7


R.A DUCT

S.A. DUCT

HEAT

R.A. DAMPER

COIL

FILTER

O.A.DAMPER

FRESHOUTDOOR

AIR

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 8


R.A DUCT

S.A. DUCT

HEAT

R.A. DAMPER

COIL

E.A.DAMPER

FILTER

O.A.DAMPER

FRESHOUTDOOR

AIR

EXHAUSTAIR

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 9


R.A DUCT

S.A. DUCT

CHILLEDWATERPUMP

HEAT

R.A. DAMPER

COIL

E.A.

DAMPER

FILTER

WATER PIPING

WATERCHILLER

O.A.DAMPER

FRESHOUTDOOR

AIR

EXHAUSTAIR

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 10


CONDENSERPUMP

R.A DUCT

S.A. DUCT

CHILLEDWATERPUMP

HEAT

R.A. DAMPER

COIL

E.A.

DAMPER

FILTER

WATER PIPING

COOLINGTOWER

HEAT

WATERCHILLER

O.A.DAMPER

FRESHOUTDOOR

AIR

EXHAUSTAIR

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 11


CONDENSERPUMP

R.A DUCT

S.A. DUCT

CHILLEDWATERPUMP

HEAT

R.A. DAMPER

COIL

E.A.

DAMPER

FILTER

WATER PIPING

COOLINGTOWER

HEAT

WATERCHILLER

BOILER

O.A.DAMPER

FRESHOUTDOOR

AIR

EXHAUSTAIR

R.A. GRILL

COOLAIR

S.A.TERMINAL

S.A.FAN

R.A.FAN


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Slide 12

Equipment Types

ROOFTOP PACKAGE UNIT

SPLIT SYSTEM

CHILLED WATER AIR HANDLER

VARIABLE AIR VOLUME (VAV) AIR TO AIR HEAT PUMP

Life expectancy 10 to 12 yrs for rooftop and split systems

Expect increase in repair costs as equipment ages

Typically largest expense to operation of store, energy/repair costs

Repair or Replace?


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Slide 13

Single Package Roof Top Unit

Most common

Entire hvac system islocated on mall roof

Most common to have

roof leaks from roof curb,condensate overflow or

roof punctures


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Slide 14


CONDR

COIL

COMP

FAN

HEAT

ELECTRICHEATER

S.A. DUCT

S.A.TERMINALR.A. DUCT

O.A.

E.A.

HEAT


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Slide 15


Rooftop package unit

Mounted on adaptorcurb

Power exhaust and

economizer installed


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Slide 16

Split System

HVAC system split into 2 pieces Condensing unit located on roof (houses

compressor, condenser coil, condenser fan motor)

Air handler located in space above ceiling (housesblower assembly, evap coil, air filters)

Connected electrically and with refrigerant piping

Most prone to refrigerant leaks especially if long

distance between components Many times refrigerant lines are buried in

construction and inaccessible


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Slide 17

SPLIT SYSTEM

COIL

HEAT

AIR

R.A. DUCT

O.A.

E.A.

FAN

CO

N

D

R

COMP

CONDENSING UNIT

REFRIGERANTLINES

S.A. DUCT

POSSIBLEELECTRIC

HEAT

AIR HANDLINGUNIT

OPTIONALSUPPLEMENTARY

HEATINGSYSTEM

HEAT


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Slide 18

SPLIT SYSTEM


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Slide 19

Split System

Air cooled condensingunit

Compressor, condensercoil and condenser fans

Connected to indoor airhandler


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Slide 20

VAV BOX

Consists of VAV terminalbox located in the spaceabove ceiling

May have supplemental

blower motor for positiveairflow to space

May have air filtration

Has a damper inside thatopens and closes on demand

from thermostat to allowmore or less airflow tospace

Variable Air Volume


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Slide 21

Major System Components

Compressor

Condenser coil

Evaporator coil

Condenser fan motor

Evaporator fan motor

Thermostatic expansion valve

Evaporator blower assembly Economizers (Optional)


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Slide 22

HEAT REJECTION(HIGH TEMPERATURE)

85F

75F95F55F

45F

CONDITIONEDSPACE

105F95F

HEAT GATHERING(LOW TEMPERATURE)

REFRIGERATIONMACHINE(REFRIGERATION CYCLE)

35F

COOLINGTOWER

95F DB78F DB

HEAT

COMPRESSOR

COOLER

CONDENSER


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Slide 24

Condenser

Condenser coil is what gets rid of the heat in thesystem

Can be water or air cooled, however most are aircooled in retail application

Located outdoors (air cooled)

Fins on coil are subject to corrosion in salt water

environment. Special coatings can be applied. Fins are subject to damage from hail

Traps dirt and requires periodic cleanings


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Slide 25

Evaporator Coil

Provides cold air to the space

Located after the system air filters

Return air is blown over the coil and chilled

Removes moisture from air (condensate)

Traps dirt that gets past air filters, reducingcooling capacity (95% is bacterial)

Requires periodic chemical cleaning


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Slide 26

Evaporator Fan Motor

Located behind condenser coil

Draws ambient air across condenser coil

System may have up to 4 or more motors based onsystem capacity

Motors are direct drive with fan blades attached

Requires little if any maintenance (sealedbearings)


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Slide 27

TXV Thermal Expansion Valve

Located at the evaporator coil Provides the correct amount of refrigerant to the

evaporator coil for proper cooling

Separates the high pressure side of the systemfrom the low pressure side

Failure could cause compressor failure and loss ofsystem cooling capacity

Frequently overlooked in diagnosing systemproblems

Requires manual setting of superheat for properoperation.


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Slide 28

Evaporator Blower Assembly

Consists of:

Blower motor

Pulleys and fan belts

Bearings

Fan shaft

Fan wheels

Housings

Can be located indoors or outdoors


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Slide 29

Control Types

CONVENTIONAL THERMOSTAT

DIGITAL PROGRAMMABLE

THERMOSTAT

PNEUMATIC

LCD SYSTEM

MALL INTERFACE


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Slide 30

Low Ambient Controls

Low ambient controls May be added to air cooled systems that must

operate when outdoor temperatures are below 55degrees

Cycles condenser fan/s to maintain correct systempressures

Used when economizer is not present

Much less costly to install

Much more costly to operate


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Slide 31

Conventional Thermostat

Completely manual operation

Will maintain a single heat or cool setting

System must be switched from heat to cool

No energy savings

Will allow system to operate all night while storeis closed wasting energy

Easy to tamper with Least expensive to install


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Slide 32

Programmable Thermostat

Provides autochangeover from heat

to cool

Provides up to 4

heat/cool settings per24 hour period

Can provide differentweekend settings

Keyboard can belocked out

Set it and forget it


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Slide 33

Pneumatic Thermostat

Uses air provided by mall to operatethermostat

Very commonly used with VAV systems

Least commonly found in malls

Parts are fairly expensive


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Slide 34

LCD Thermostat

Used in newer stores

Programmable type

Can be dialed into by monitoring companyfor data


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Slide 36

Rules Of Thumb

1HP = 1KW = 1KVA 1KW = 3413 BTU

1 Ton Cooling = 12,000 BTU 1 Ton = 400 CFM

Retail = 380 SQ FT/ Ton cooling

Delta T = 18F across coil cooling Delta T = 25F for heating

CFM = Building Volume in Cubic Feet

Minute/Air Change

Delta T = Difference between entering and leaving DB = T


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Slide 37

Servpro of Great Neck /Port Washington

For Further Information

Please Contact Us:

516-767-9600

ServproOfGreatNeck.com
http://servproofgreatneck.com/http://servproofgreatneck.com/

102_Air Conditioning Basics

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