Theme 1 - HVAC Flashcards
What does HVAC stand for?
Heating Ventilation & Air Conditioning
Def of HVAC:
HVAC system uses various technology to control air purity, air temp, relative humidity, air change rates & pressures in enclosed space,
with purpose of providing acceptable indoor air quality in proportion to the purpose of enclosed space.
Why do people want a HVA controlled environment?
To create an environment in a space that supports the purpose/ process for which the space was created
Act 85 of 1993:
Occupational Health & Safety Act
Act 103 of 1977:
National Building Regulations & Building Standards Act
Name 3 common acts applicable to the HVAC industry:
Act 85 of 1993
Act 103 of 1977
SANS 10400
SANS 10400:
National Building Regulations (NBR)
What are the comfortable ranges in tamp & relative humidity?
Temp18-27 grade C
RH 20-60
Natural ventilation
Openings at low/ high level
Usually not controlled
Room conditions is based on natural air movement only
Openings required should be calculated
Without any filtration
Stores
Warehouses
(size dependent)
Forced ventilation
Fan only/ fan-filter unit/ supply exhaust/ thermostat & timer control
Room conditions a function of internal loads & ambient
Usually filtered
Transformer rooms
Switchgear rooms
Flammable stores (Flammable ventilation operates 24/7)
Lift motor rooms
What does a fan intake plenum include?
Filters
Sound attenuators
Ducting
Air terminals
Air volumes depends on:
- Application (offices/ health, educational, industrial - facilities
- Regulation fresh air requirements & air change rates
- Room heat loads (building/ people/ equipment/ special exhaust air requirements
- Can be constant/ variable
Filtration
Removes pollutants & improves air quality.
Pressure differentials measured by applications.
Pressure control
Measured in Pascal (Pa)
Higher/ lower than adjacent room
Controlled parameter
Depends on application
Cleanrooms usually + (can be -, depend on product)
Containment laboratories -
