HVAC Service Class

HVACHeating Ventilating & Air Conditioning

By: Anthony D. Adams & Mark GuddeMarch 2006

This HVAC presentation is made up of two parts;

Part 1; Components of the system and what they do Part 2; Diagnosing service issues, when to call in the

technician

HVAC

• Today we will show you;• The major components of the HVAC

system• Smaller components of the system; what

they are called and what they do• Diagnostics that you can do and when to

call the technician.• There will be hand outs

Major Components

• The heating ventilation & air conditioning (HVAC) system is made up of many large components which are in turn made up of many smaller specialized components. First let’s see what the major components of the system are. We will later break each major component down into its individual, specialized components.

Heating

• Forced air gas (fag) furnace

• Add-on heat pump (air source)

Air Conditioning

A-Coil located Inside

Condenser located outside

Ducting System

Ducts distribute the conditioned air in the home

Thermostat

• Thermostat monitors temperature (comfort level), starts and stops the appropriate heating or cooling system

Line Set

Line set distributes coolant (Freon) between outside components, the condenser and compressor, to the A-coil located inside the home.

Line set composed of one bare copper line and one insulated copper line

Electricity

Electricity provides the Power to Operate Fans, Compressors, Thermostats, Computer Boards, Switches, and Sensors required for the various systems to operate.

Gas line

Gas line brings the fuel to the fag furnace

Water Heater

Is the water heater part of the HVAC system?

Water Heater

Pop Quiz

What major components does it take to provide the heating, ventilating, and air conditioning for the homes we build?

Major system components

• Heating (fag)• Cooling• Add-on heat pump (heating)• Ducting• Thermostat• Line set• Electricity• Gas line

Further Breakdown

• In this next section we will break down these major components into smaller parts and pieces and explain what role they play in making the system work.

Heating (fag)

A-Coil

Heating (fag)

A-Coil

Heating (fag)

A-Coil

Heating (fag)

Burner/heat exchanger

Heating (fag)


Heating (fag)


Heating (fag)


Heating (fag)

Blower

Heating (fag)

Blower

Heating (fag)

Blower

Heating (fag)

Blower

Heating (fag)

A-Coil


Blower

Pressure Sensing Switch

Draft Inducer Motor

Draft Inducer Motor

Gas Valve

Gas Valve

Burners

Burners

Burners

Roll out limit Switch

Flame Sensor

Igniter or glow plug

Main limit switch

Power Switch

Pop Quiz

Components at Burner Door• Pressure Sensor Switch• Draft Inducer Motor• Gas Valve• Burners• Roll-Out-Limit Switch• Flame Sensor• Igniter• Main Limit Switch• Power Switch

Service Switch

Fresh air ventilation control

Control board

Control board Close Up

3 Amp Fuse

Diagnostic L.E.D.s

Pop Quiz

Components at Blower Door

• Service Switch• Fresh Air Ventilation Control• Control Board• 3 Amp Fuse• Diagnostic L.E.D.s’

Air Conditioning/Cooling

Air Conditioning Condenser

Air Conditioning/CoolingLine Set

Connecting the Condenser and A-Coil


Air Conditioning A-Coil



1. Compressor

2. Condenser fan

3. Coil (like a radiator)

4. Service valve

7. Electrical service panel


• Air Conditioning Condenser

Compressor



Compressor



Compressor



Condenser fan



Coil (like a radiator)



Service valve



Electrical service panel

Capacitor

Defrost control board

Outside thermostat

Points



Pop Quiz by the Numbers

1. Compressor2. Condenser fan3. Coil (like a radiator)4. Service valve7. Electrical service panel

Add on Heat PumpSome Terminology & How it Works

• Reversing valve• High pressure line• Low pressure line• Freon, gas or liquid?• Heat is relative

Heat Pump Diagram

Heat Pump Diagram

Thermostat

Old style thermostat

Thermostat

Cover off exposing two mercury switches and wiring

ThermostatBoth mercury switches are circled and mercury is all the way

to the left of both switches therefore “no demand” condition

No demand

ThermostatNote; Top mercury bulb has tilted. Mercury has flowed to the

right and made contact across the contacts.

Initial demand

ThermostatNote; Both vials have tilted enough so both vials

have mercury in contact across the electrodes

Full demand

Present Day Thermostat

Digital

Entertainment & Humor

HVAC Service Class