HVAC Systems and Types of HVAC Systems- How They Work
Name- Advait Joshi
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BAPA HA - Blog
HVAC Systems and Types of
HVAC Systems- How They Work
What is HVAC System?
“HVAC” stands for heating, ventilation and air conditioning, and refers
to any system that provides ventilation or temperature control for a space.
These systems include everything from central air and heating to portable space
heaters and AC units, and there are multiple types to choose from.
Each
type of HVAC system falls into one of two categories: ducted or ductless. In a
ducted system, the main unit pushes air through a series of air ducts to cool
or heat a building. Ductless systems, on the other hand, lack air ducts and use
alternative methods to distribute treated air throughout a space.
Types of Ducted HVAC Systems
If a
building uses vents to pump out hot and cold air, it is likely equipped with a
ducted HVAC system. Ducted HVAC systems are standard in residential and
commercial buildings and include any heating or cooling system that distributes
air through a series of air ducts.
1. Split System
Heating
and cooling split systems are the most common types of HVAC systems used in
residential buildings. They consist of two separate components — one for
heating and one for cooling — and use a traditional thermostat to control the
temperature for the entire structure.
In
most buildings with split systems, the heating unit is located in a basement,
utility closet or other indoor storage space. The heater is gas-powered and
uses an evaporator or fan to push heat through a building’s ductwork. On the
other hand, the cooling system is located outside and connects to a building’s
ductwork through a series of tubing. It uses compressors, coils and refrigerant
to create cool air, and a fan directs hot air out and away from the building.
Key
Feature: One thermostat controls the
temperature for the entire unit
2. Hybrid Split System
A
hybrid split HVAC system has the same structure and cooling unit as a split
system but doesn’t rely solely on gas to create heat. While its heater can burn
gas, it can also switch to electric power. Electric heating is often slower and
less powerful than gas-powered, but this option gives building owners more
control over their building’s energy consumption and can help reduce energy
costs in milder climates.
Key
Feature: Reduces energy consumption
3. Packaged Heating and Cooling
Packaged
heating and cooling systems are less common than split systems, but their
smaller size makes them better suited for small buildings lacking extra storage
space. The heating and cooling components are housed in a single unit and are
generally stored on a roof, in an attic space or near the building’s
foundation.
Packaged
HVAC systems connect to a building’s supply and return ducts, often through a
single hole in the wall. Depending on the climate, building owners can choose
to install a packaged heat pump containing evaporator coils or a packaged air
conditioner with an air handler with optional heat strip elements. Both systems
cost less to install than split systems and are easier to maintain.
Key
Feature: Single unit is easy to maintain.
4. Zoned System
HVAC
zoning systems afford occupants greater control over the temperature in
separate rooms or areas in a building. Technicians can zone ducted HVAC systems
in a few different ways, and the best method often depends on the size of the
building. For example, people who own larger homes may choose to install
multiple HVAC systems to control the temperature on different floors. Because
each system is completely separate, this type of zoning requires building
owners to install two or more heating and cooling units.
Another
common type of zoning involves installing manual or automatic dampers in a
system’s air ducts to control the amount of airflow in different areas.
Partially closing a damper restricts airflow to one zone while pushing it
toward another, making it easier to adjust each room to its ideal temperature.
This type of zoning creates a more comfortable environment for occupants and
improves energy efficiency by directing air away from zones that don’t need it.
Key
Feature: Allows for more personalized
temperature control.
Types of Ductless HVAC Systems
As
the name suggests, ductless HVAC systems are designed to heat or cool a space
without air ducts. These systems come in various sizes and are commonly used in
small buildings or temporary work sites.
5. Duct-Free Mini-Split
Ductless
mini-split systems are installed in individual rooms and are common fixtures in
multifamily homes, office buildings and hotel rooms. Also known as mini-split
systems, these electric units include an outdoor compressor and condenser,
refrigerant, an indoor air-handling unit, a heat pump, power cables and a thermostat
for each zone. Copper tubing connects the indoor and outdoor components, and
one compressor can connect to up to nine indoor air-handling units.
While
duct-free systems can be expensive to install, they often help reduce energy
costs and consumption over time. Their flexible zoning capabilities allow users
to heat and cool occupied rooms only, preventing energy loss associated with
ductwork. However, the heating components are less effective in below-freezing
temperatures, so people living in colder climates often need to add a separate
heating system.
Key
Feature: Provides ductless temperature
control for individual spaces
6. Hydronic Heating
Unlike
the other HVAC systems in this list, hydronic heating uses liquid rather than
air to radiate heat. This system uses a boiler to heat water, then distributes
it throughout a building using a series of pipes under the floors. Once the
liquid reaches a radiator or baseboard heater, it distributes heat throughout
the room. Homeowners can also install a radiant flooring system that uses
hydronic heating to heat their floors.
Key
Feature: Uses liquid to radiate heat
7. Portable Spot Cooler
Spot
coolers are portable AC units designed to cool down large rooms, manufacturing
facilities or outdoor spaces. They work by drawing in ambient air, pushing it
over a closed-loop coil cooled by refrigerant and pumping it back into the
space. The coil cools and removes humidity from the air, creating leftover
condensation that drains out into a hose or catch bucket.
Spot
coolers can operate in any location with an electrical power source, and
attached wheels make them easy to move. That said, finding a place to let out
the exhaust can make setup in enclosed spaces more difficult. After cooling the
air, spot coolers pump leftover warm air out through a flexible exhaust tube.
This tube is usually extendible, and it must lead out through a door, window or
drop ceiling to prevent warm air from re-entering the space.
Key
Feature: Portable and easy to set up
8. Portable Heat Pump
A portable
heat pump is similar in size and operation to a spot cooler but offers an
additional heating option for colder environments. When switched to heating
mode, a heat pump draws in outside air, runs it over a condenser coil and disperses
warm air throughout the room. A reversing valve inside the unit allows users to
switch between heating and cooling capabilities, making it a good option for
varying climates.
Key
Feature: Has both heating and cooling
capabilities
Whether
you’re installing a new HVAC system or need a temporary Temperature
control solution or your job site, there is an HVAC system out there that can
meet your needs. If you need help deciding between the types of HVAC systems
listed above, an HVAC specialist or contractor can help you find a compatible
option for your building.