HVAC Equipment System Selection
HVAC equipment systems are used to control indoor air quality and temperatures in buildings. They provide comfort and energy savings. In addition, they ensure safety and productivity. There are different types of HVAC systems depending on the type of building and its needs.
The selection of an HVAC system requires consideration of many factors, including the following:
1. Building Configuration
This refers to the type of structure being built (i.e., single-family home vs. multi-family unit).
2. Climate Conditions
Climate conditions are important because they affect the amount of energy needed to heat or cool a particular area. For example, a hot summer day in Las Vegas might require less air conditioning than a cold winter day in New York City.
The design engineer is responsible for choosing the most appropriate air conditioning system for a specific building project. He or she considers several parameters including the building configuration, climate conditions, and the owner’s desires.
Some criteria can be considered such as climate change (temperature, humidity, and space pressures), building capacity, spatial requirement, costs such as capital costs, operating costs, maintenance costs, life cycle analysis, reliability, and flexibility.
However, the selection of an HVAC system has some constraints that are determined. For example, the available capacity according to standard, building configuration, available spaces, construction budget, the availability of utility sources, and heating and cooling building load.
Basic Components of an HVAC System
The basic components or equipment of typical residential heating, ventilation, and air conditioning (HVAC) system are listed below.
Mixed-Air Plenum and Outdoor Air Control
An air handler unit contains one or more blower/compressors. This component draws outside air into the building through an air intake opening located near the foundation wall. Inside the home, the mixed-air plenum serves as a mixing chamber where incoming cold outdoor air mixes with warm return air from inside the house. A diffuser box directs the flow of air throughout the home.
Air Filter
An air handler unit contains one or more blower/compressors. This component draws outside air into the building through an air intake opening located near the foundation wall. Inside the home, the mixed-air plenum serves as a mixing chamber where incoming cold outdoor air mixes with warm return air from inside the house. A diffuser box directs the flow of air throughout the home.
Air Filter
A HEPA filter removes particulates such as dust from the incoming air stream. In addition to filtering out contaminants, it helps maintain the efficiency of the air handler unit. An electrostatic precipitator (ESP) filters particles down to 0.1 microns or smaller. These small particles are too fine to see with the naked eye but can cause serious health problems.
Supply Fan
This device moves the mixture of air into the supply registers. Each register is designed to provide a specific volume of air to each room. The air flows through ductwork and vents to reach the rooms.
4. Classification of HVAC Systems
The major classification of HVAC systems is a central system and a decentralized or local system.
Types of a system depend on the address of the primary equipment location to being centralized as conditioning an entire building as a whole unit or decentralized as separately conditioning a specific area as part of a building. Therefore, the air and water supply system should be designed based on system classification and the location of the primary equipment.
The criteria mentioned above should apply in selecting between two systems.
Criteria Central System Local System Temperature, humidity, and space pressure requirements Fulfilling any or All of the design parameters Fulfilling any of the design parameters Capacity requirements Redundancy Standby equipment is accommodated for troubleshooting and maintenance No backup or standby equipment special requirements Cost First Cost Operating Cost Maintenance Cost Accessible to the equipment Room for maintenance and saving equipment In excellent condition, which save maintenance costs Accessible to the equipment to be located in the basement or the living space.
If you need assistance determining the proper HVAC equipment for your project contact the professionals at Tekneca HVAC design today.