Window Air Conditioning System: Definition, Working principle and Pros and Cons
A window air conditioner, also known as a box air conditioner or wall air conditioner, is a self-contained cooling system that is installed into a window or wall opening. It contains all the components necessary to cool and circulate air in a single unit.
Window air conditioners are commonly mounted in a window frame or wall sleeve. This allows the interior air to be cooled while venting the hot air outside. They are easy to install and require only a power outlet nearby to operate.
Window air conditioners are very popular in residential settings, especially older homes without central air conditioning. They can cool one or a few rooms at a time. According to Australian statistics, over 35% of households use window or wall air conditioners. They are also used frequently in small commercial spaces like offices, server rooms, workshops, etc.
The window air conditioner cools indoor air using a refrigeration cycle. A compressor pumps refrigerant that absorbs and removes heat from the air inside the room. This cooled air is then blown out through the front vent using a fan while the hot air is exhausted outside. Some models also have a heating mode that reverses the cycle to bring warm air into the room.
Window air conditioners have the advantage of being affordable, easy to install DIY, and allow zoning certain areas for cooling and heating. As they are compact units, window ACs do not take up floor space. They provide spot cooling and are energy efficient.
The major downside is that a window or wall space is occupied by the air conditioner which blocks natural light and views. They can be noisy and need to be removed or covered during winter. Installation in a rental property requires permission.
In Australia, a new window air conditioner typically costs between $400 to $800 depending on the capacity and features. Installation by a professional may cost extra $100 upwards if wall sleeves or electric work is also required. Operating costs are around 20 to 25 cents per hour depending on the unit’s energy rating.
What is a Window Air Conditioning System?
A window air conditioner is a compact, self-contained cooling system designed to be installed in the window or wall opening of a room. It contains all the basic components of refrigeration in a single box - evaporator, condenser, compressor, expansion valve and refrigerant.
The working principle involves a refrigeration cycle where heat is absorbed from the air inside, transferred outdoors, and emitted to the exterior leaving cooled air to circulate indoors. Moisture may also be dehumidified in the process. All this is done using a small hermetically-sealed system charged with refrigerant gas and needing just an electrical outlet to power the operation.
The main advantages of window ACs are - easy installation, affordability, zone or spot cooling so only needed spaces get chilled, does not occupy room space and flexibility to take the unit out when not required.
Who invented the window air conditioner?
The origin of the modern window air conditioner dates back to 1945 when two engineers from the Chrysler Motors Corporation - Robert Sherman and Robert Schriber - invented the compact unit to meet the cooling needs in buildings.
The history behind this technological advancement was the demand for affordable air conditioning following World War 2. Central cooling systems were complex and expensive to install so a cheaper, versatile alternative was created for houses, apartments and offices.
What made this possible was the availability of improved synthetic refrigerants and sealed unit components that did not require specialised skills or tools to fit into the existing structure. The window air conditioner was user-friendly, consumed less power compared to a large system and provided zonal temperature control. This novelty caught on quickly and by the 1950s, window ACs became very popular in Australia's warmer parts. Today, simpler versions continue to provide spot cooling and heating in homes and workspaces cost-effectively.
How does a window air conditioning System work?
Window air conditioning systems work by transferring heat from the interior air to the outside leaving cooled and dehumidified air to circulate indoors for comfort cooling. The same system can reverse the refrigerant flow to absorb outdoor heat and release it inside for heating.
For cooling, the window AC uses a vapour compression refrigeration cycle leveraging phase change of refrigerant between liquid and gas. The most widely used eco-friendly refrigerant today is R410a. Air from the room enters the AC unit and passes over cold evaporator coils, lowering its temperature. Liquid refrigerant in the coils absorbs heat and evaporates into gas which is then pumped to the condenser by the compressor.
Here, the hot compressed gas dissipates heat outdoors via the condenser and turns back into liquid. The refrigerant goes through a pressure lowering expansion valve and returns to the evaporator at cool low pressure to repeat the heat absorption process. This refrigerant flow from indoors to outdoors transfers room heat outside thereby providing cool conditioned air.
For heating, the cooling process is reversed via a valve that makes the refrigerant flow backwards. Heat from outdoor ambient air gets absorbed into the refrigerant gas while passing through the outdoor condenser coil. Then it releases this heat indoors from the room-side evaporator coils. Thus warm air is circulated inside for heating effect.
The amount of heating or cooling produced depends on the window AC unit capacity, ranging from small 1.47 kW systems for 150 sq ft rooms to larger 3.52+ kW units for bigger spaces. Performance also varies based on energy efficiency ratings denoted by the stars on the appliance.
What are the window Air conditioning System Components?
The key components of a window air conditioner are:
- Evaporator - Coil that absorbs heat from interior air and evaporates refrigerant into cold gas
- Condenser - Coil emitting heat from condensed refrigerant gas to outdoors
- Compressor - Pump that pressurises refrigerant gas from evaporator and pushes it into the condenser
- Expansion valve - Positioned after the condenser to lower refrigerant pressure before it enters the evaporator again
- Fans & Grills - To blow air over the evaporator and condenser coils
- Air Filters - To clean the circulating indoor air providing better air quality
- Control Panel - With buttons for power, mode, thermostat, fan speed and timers
What is the window Air conditioning System Type?
Window air conditioners come in different capacities to match room sizes, such as 1.47 kW can cool 150 sq ft, and 3.52+ kW for 550+ sq ft. Physical dimensions and weight increase with higher capacity. Another distinction is between Energy Star rated energy efficient models vs standard models. Smart ACs can connect to home WiFi for app controls. Overall types cater to cooling capacity needs and advanced functionality.
What are the Pros of Installing a Window Air conditioning System?
The key benefits of installing a window air conditioning unit are:
- Saves on cooling costs compared to operating a central AC system
- Allows zoning so only spaces that need cooling are chilled
- Easy to retrofit into existing homes without ductwork
- Higher portability as window ACs can be moved from room to room
- Improve comfort by providing cool dry air during hot weather
- Enhance property value by adding modern amenities for tenants
What is the capacity of a window Air Conditioning System?
The cooling capacity of an air conditioner is measured in kilowatts (kW).The average cooling capacity of window air conditioners ranges from 1.47 kW for 150 sq ft rooms to 7.03 kW for spaces above 1,000 sq ft. Though units are available from small 0.73 kW sizes to larger 10.55 kW capacities as well. Matching AC capacity to room dimensions is key for optimum temperature regulation.
What is the noise level (dB) on a window Air Conditioning System?
Noise is an important consideration for homeowners when installing any air conditioning system. High decibel units can make it uncomfortable to sleep, work or relax.
Average noise levels of window ACs range between 50 dB to 60 dB which is noticeable but not intrusive. This compares well to the typical noise of central split system compressors that produce 70+ dB outdoors due to the large fan units.
With sound insulation sleeves and proper installation, window air conditioner operation can be quite quiet and the white noise may even drown out external sounds for some users.
What are the Cons of Installing Window Air conditioning Systems?
The downsides to keep in mind when installing a window air conditioner are:
- Reduce natural light as the AC unit blocks window or wall space
- Higher noise levels compared to a ducted or split system, especially for smaller capacities
- Risk of weather or dampness damage if insulation around the air con is inadequate
- Less aesthetic appeal as the appliance is visibly mounted inside the room
- Limitation for rental properties due to strata regulations on external fixtures
- Recurring seasonal costs to remove and reinstall the AC every year
Additional installation challenges include:
- Requiring strong window support and weatherproofing
- Sourcing extra long curtains or blinds to cover the appliance
- Protrusion from the building facade affecting external appearance
- Ongoing maintenance to keep filters clean for optimal efficiency
- Finding a reliable power outlet in proximity
So while window ACs provide inexpensive spot cooling, there are significant disadvantages regarding noise, visual appeal and potential structural modifications. Carefully evaluate on a case by case basis.
Is the Window Air Conditioning System good for residential buildings?
Yes, window air conditioners are a good cooling and heating option for Melbourne homes due to affordability and zonal temperature control. As the majority of older houses lack ducted systems, installing window ACs allow chilled air in bedrooms, living areas and studies without needing to cool unused spaces. The seasonal nature of Melbourne's climate also means these portable units can be removed to retain aesthetic appeal in cooler months.
Is the Window Air Conditioning System good for commercial buildings?
Window air conditioning units have limited applications in Melbourne's commercial buildings unless cooling requirements are minimal. While suitable for small offices, window ACs may not meet the higher capacity, networking and redundancy demands of larger open plan offices, retail stores or other commercial premises. Split ductless types or multi-head systems offer greater flexibility.
Is Window Air conditioner Good for Melbourne Climate?
Yes, Melbourne's temperate climate makes window ACs a practical solution for spot heating and cooling. Summer peak temperatures average around 26°C meaning moderate capacity units are sufficient for most spaces. The significant variance between seasons also allows the units to be uninstalled during the cooler winter months. This avoids negatively impacting building insulation or aesthetics.
Overall, the seasonal installation works well for Melbourne allowing residents and businesses to cost-effectively retrofit air conditioning into their spaces only when required rather than needing year-round ducted infrastructure. DIY fitting also means upgrades can be made to rentals and strata buildings too.
What is the best Window Air conditioning Brand in Australia?
Panasonic, Fujitsu, Daikin, and Mitsubishi Electric are among the top window air conditioner brands in Australia. These Japanese brands are known for higher reliability, energy efficiency and quieter operation because of superior compressor and component quality. They receive consistently good consumer reviews as value for money models with lifespans averaging 8 to 10 years depending on usage and maintenance practices.
How much does it cost to Install a Window Air Conditioning System?
The typical price to install a window air conditioner in Australia ranges between $500+ for a standard unit including labour and materials. Larger capacity systems above 5.28 kW may cost $450 to $1000 for installation.
The labour expense to fit window ACs is lower because the job usually takes only 1-2 hours for an experienced technician. This assumes there is existing framing and the necessary power socket in place. Any additional electrical work, fitting heavy duty support brackets or weatherproofing can increase overall costs. Supply of the air conditioning unit itself is an extra upfront purchase starting from $400 for good quality brands.
Main variables that impact install pricing are - cost of the AC unit itself based on brand, capacity and features, complexity of electrical connections, fitting wall support, custom window frame work, cooling capacity differences and adding advanced functionalities. Get quotes from accredited technicians to compare pricing for your specific scenario.
How much does it cost to purchase a window Air Conditioning System?
The average cost to buy a Panasonic window air conditioner is $550.The most expensive Panasonic window air conditioning unit is the 3.52 kW model for $899.The cheapest Panasonic window air conditioning model is the 1.76 kW unit for $499.The average cost to purchase a Fujitsu window air conditioner is $650.The highest priced Fujitsu window AC is the 4.10 kW for $1,099.The lowest priced Fujitsu window unit is the 1.61 kW for $579.
What is the warranty period of a window Air Conditioning System?
A warranty is an assurance to fix or replace manufacturing faults in the product for a stated time period. It covers both parts and labour within scope during the validity.The standard industry warranty provided on window air conditioners is between 5 to 7 years on the compressor part and 1-2 years on other components. Most brands offer options to extend the warranty additionally for around $100 to $200 per year.
At Oz Air Group, we provide in-house warranty for 5 years on compressors and 2 years on parts and labour. This covers any deficiencies due to the unit’s materials or workmanship as per policy terms. We have skilled teams to promptly troubleshoot and resolve any warranty issues.
Does window Air Conditioning System require maintenance?
Yes, basic maintenance is recommended for window air conditioners to enhance performance and longevity. This involves more frequent filter cleaning, coil brushing and checking refrigerant levels compared to split ducted systems.
Maintenance is simpler than central air conditioning as the external mounting provides easy DIY access. No roof access or disassembling indoor units is necessary. Just wiping down debris, vacuuming vents, clearing condensate drains and annual pro services aids efficiency.
How to Maintain a window Air Conditioning Units
Tips to maintain window air conditioners:
- Check and clean air filters monthly in summer or as needed
- Clear debris and vegetation near outside vents
- Vacuum inside the unit cabinet to remove dust buildup
- Clean evaporator and condenser coils yearly
- Top up refrigerant levels if cooling is inadequate
- Ensure unobstructed air flow and adequate room ventilation
- Get professional chemical cleans every 2-3 years
How long does a window Air Conditioning System last?
The average lifespan of a quality window air conditioner is 8 to 12 years. Proper usage and maintenance practices can enhance longevity. Location also plays a key role - hot humid climates cause more wear and tear than temperate regions. With care, window ACs can even operate reliably for 15+ years before efficiency drops considerably requiring a replacement.
What are the alternatives to window Air conditioning?
The main alternatives to window air conditioners are portable mobile air conditioners, split system air conditioning units (both wall mounted and ducted), as well as evaporative coolers. Each offers different installation flexibility, upfront costs, running expenses, cooling capacities and features.
Considering Melbourne's climate, homes that lack existing ductwork may benefit most from a split system heat pump with both heating and cooling abilities. Though the higher initial purchase and installation price should be evaluated against long term savings.
Window Air Conditioners vs Portable Air Conditioners
The main difference between window and portable ACs is that window air conditioners need to be secured firmly into a window space or custom built wall sleeve, while portable units have wheels and exhaust hoses allowing them to be moved room to room.
Window air conditioners also tend to have higher energy efficiency and cooling capacity for the unit size. But portables offer more placement flexibility in spaces where permanent mounting is not possible like rental homes. Noise levels are comparable depending on BTU ratings.
What is the best Air conditioner Type for Melbourne Climate?
Considering Melbourne's temperate climate, the best air conditioner type is a reverse cycle split system heat pump. These ducted or wall mounted units provide both heating and cooling from the same appliance using refrigerant flow reversal. This suits the seasonal demands avoiding the need for separate heaters.
Variable Inverter types adjust compressor speed based on ambient temperatures allowing optimised comfort control and great energy savings. They can be zoned to different areas as required while maintaining aesthetic appeal without bulky window units. With good insulation, even entry level split systems perform remarkably well across Melbourne's climate.
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