With growing temperatures across the world due to climate change and global warming, air conditioners are becoming very common components of buildings, including small residences. However, before installing an AC in your home, it is important to understand exactly how it functions. Keep reading to learn precisely what an air conditioner is, its components, process of operation, limitations, when it is really required in buildings and tips for AC maintenance.
What is an Air Conditioner?
An air conditioner (AC) is an electrical device that is used to control indoor air quality, temperature and humidity. Its main purpose is to provide cooling in enclosed spaces and it operates using electrical power. The first modern electrical AC was invented in 1902 by Willis Carrier, who founded a company that manufactured HVAC systems in 1915, forever transforming the way thermal comfort is ensured in indoor spaces.
Components of an AC
An air conditioning unit typically consists of the following elements that aid its functioning:
Heating and Cooling Elements
- Refrigerant: This is a special chemical that changes its form from gaseous to liquid state and vice versa in an AC unit. It has the ability to expand and compress itself to provide heating or cooling.
- Compressor Coils: A compressor is an element used to heat the refrigerant. It is generally located in the outdoor AC unit and is responsible for a major portion of energy consumption by the system.
- Condenser Coil: Also present in the outdoor AC unit, the condenser coil helps in expelling hot air outside.
- Evaporator Coil: Typically made of copper, steel or aluminium, an evaporator coil is located in the indoor unit of an AC. It helps expel heat from the air, therefore cooling it in the process.
Air Filters
Air filters in ACs are mesh-like screens that capture dust and dirt from the air, preventing their spread in indoor spaces. They also trap these air-borne particles and stop them from entering the AC system itself, thus ensuring its smooth and efficient functioning. These filters can generally remove air-borne particles that have sizes of 0.3-10 microns in diameter.
Distribution Systems
Heating and air conditioning are carried out by different distribution systems that carry hot or cold air from the inside to the outside and vice versa. Typical components of these systems are:
- Ducts: These are long conduits that distribute the conditioned air to the required spaces and take back the returned air to the heating/cooling elements for further treatment. Ducts are generally made of sheet metals or other similar flexible materials, helping them to curve across floors and ceilings at different levels. Air velocity in low-velocity ducts is less than 760m/ min, while high-velocity ducts allow larger speeds.
- Air Inlets and Outlets: These systems consist of grilles and diffusers which allow the air to enter or exit the AC unit at particular angles and speeds. Profiled blades made of aluminium, mild steel, stainless steel or plastic enable this movement.
- Fans: Axial and/or centrifugal fans move air through the ducts and other resistances that form a part of the distribution system.
How Does an AC Unit Work?
The functioning of an air conditioner generally follows the below steps:
- The temperature and pressure of the refrigerant gas are raised by the compressor unit.
- The heated refrigerant gas moves towards the condenser, which exposes it to the outside air. The heat from the refrigerant gets expelled here, cooling it and converting it into a liquid. It then moves towards the evaporator coil.
- Warm air is sucked into the AC inlets and passes through the evaporator coil. Here, heat is absorbed by the refrigerant liquid and air gets cooled.
- The cooled air passes through air filters and gets distributed into rooms through ducts and air outlets, aided by pressure from the fans.
Tips for AC Maintenance
Different types of air conditioners require different maintenance processes and time periods between maintenance checks. However, some of the common AC maintenance strategies that can be followed are:
- Inspect and clean air filters at least once in 3-4 weeks.
- Switch on the AC for a few minutes at least once a week, even if it is not necessarily required. This ensures that air filters, inlets and outlets do not get clogged with dust.
- ACs must be inspected and serviced at least once in 9-12 months by professionals. This servicing needs to include the cleaning of condenser drains and coils and checking of the refrigerant levels
- The servicing can happen more frequently when any troubling signs are noticed.
Common Signs of Trouble with ACs
- Spread of foul smells
- Insufficiently cooled air
- Visible liquid leakages
- Excessive noise while operating
- Presence of air-borne particles
When any of these signs are spotted, professional AC servicing agencies must be called to inspect and/or repair the units
Limitations of Home Air Conditioners
- Cost: Apart from the initial air conditioner installation and product cost, regular maintenance and daily operational costs are also very high. Residential utility bills can increase by around 30% by just using one AC.
- Maintenance: Clogging or contamination of air filters can help breed infectious bacteria and micro-organisms, spreading air-borne diseases faster. Leakage of the refrigerant liquid can also be harmful and lower the indoor air quality drastically. Thus, an AC requires frequent maintenance to prevent these issues and ensure its efficient functioning.
- Energy Consumption: Even a small air conditioner consumes a lot of energy to operate, discouraging sustainable building practices. Leaking of the refrigerant liquid from ACs can also lead to the depletion of the ozone layer, furthering the issue of global warming.
When is a Room Air Conditioner Required?
Sufficient cooling can be achieved through cross ventilation and passive architecture in most situations. Air conditioners are required only in certain climatic conditions or circumstances such as:
- Large commercial structures with too many occupants for adequate natural ventilation, such as shopping malls or multi-storey office buildings.
- Regions which face extremely warm and humid or hot and dry climates.
- Factories, warehouses, or industries that emit a lot of hot gasses that need to be replaced with clean, cool air.
- Places where windows and other openings are almost impossible to open due to excessive noise, poor air quality, or harsh weather.
- Structures on constrained urban sites where it is difficult to include enough windows and openings.
- Places like hospitals and research labs that require highly regulated indoor air quality.
- Spaces where hot air extraction and fresh air supply are necessary due to their closed nature, such as theatres and auditoriums.
- Buildings which require extreme security or privacy, such as jails and government buildings.
Ensuring the Best Air Conditioners in Home Design
Although air conditioners can easily and conveniently be fixed in any space, they are required only in certain locations and under certain climatic conditions. In other places, their necessity can be eliminated by adopting climate responsive architecture and passive design techniques. Such strategies can help buildings be more energy efficient and sustainable. With end-to-end design-build services, Brick & Bolt is a leading construction company that provides customised floor plans for every project, limiting the need for ACs in residences. To get your dream home designed on the basis of expert analysis of AC requirements and with the latest technologies, get in touch with Brick & Bolt today!
Apoorva H P Achar