Understanding HVAC Systems

HVAC systems are designed to regulate indoor environments by controlling temperature, humidity, and air quality. Common components include air conditioners, furnaces, heat pumps, boilers, and air purifiers. These systems work by drawing in air, conditioning it through heating or cooling elements, and distributing it throughout the building via ductwork. Modern HVAC systems often incorporate filters or purifiers to remove dust, bacteria, and allergens, and some include humidifiers and dehumidifiers for moisture control

Understanding The components of HVAC system

1. Thermostat

2. Furnace

3. Heat Exchanger

4. Evaporator Coil

5. Condenser Coil

6. Blower Motor

7. Ductwork

How to calculate cooling load

Q = 1.1 × CFM × ΔT

• Q = Cooling load (BTU/hr)

• CFM = Airflow rate (cubic feet per minute)

• ΔT = Temperature difference between return and supply air (°F)

How to calculate heat transfer through surface in hvac

Calculates the rate of heat transfer through a building component like a wall or window

Formula:

Q = U × A × ΔT

• Q = Heat transfer rate (BTU/hr)

• U = Overall heat transfer coefficient (BTU/hr·ft²·°F)

• A = Area of the surface (ft²)

Electrical Power Calculation

Formula:

P = V × I × PF

• P = Power (Watts)

• V = Voltage (Volts)

• I = Current (Amperes)

• PF = Power factor (dimensionless)

Air Changes Per Hour (ACH)

Formula:

ACH = (CFM × 60) / Room Volume

• CFM = Airflow rate (cubic feet per minute)

• Room Volume = Length × Width × Height (cubic feet)