Air Conditioning

Air conditioning units are systems designed to control the temperature, humidity, and air quality within indoor spaces. While traditionally associated with cooling, many modern units are also highly efficient heat pumps, meaning they can provide both cooling in summer and heating in winter.

An air conditioning unit works based on the refrigeration cycle, specifically the vapour-compression refrigeration cycle. This process doesn't create cold air, instead, it removes heat from an indoor space and expels it outdoors.

It's essentially the same principle as how your kitchen refrigerator cools its contents, but on a larger scale to condition a room or an entire building.

Ultimately, an AC unit is a sophisticated heat pump that cleverly manipulates the state of a refrigerant to move heat from where you don't want it, inside, to the outside. 

Portable Air Conditioners: These are self-contained, mobile units that sit on the floor. They typically have a hose that needs to be vented out a window to expel hot air and accumulated moisture.

Pros: Highly flexible and easy to move between rooms. No permanent installation required, making them suitable for renters or temporary cooling needs. Relatively inexpensive upfront.

Cons: Generally less efficient than other types due to their single-unit design, which can sometimes lead to heat leaking back into the room. Can be noisy. Take up floor space and may require frequent emptying of a water reservoir.

Best For: Cooling single, small to medium-sized rooms (typically under 500 square feet/46 square meters) where permanent installation isn't feasible or desired. Good for bedrooms, home offices, or as supplemental cooling.

Window Air Conditioners:  A compact, self-contained unit designed to be mounted in a window frame (or sometimes through a hole in an exterior wall). The front part faces indoors, and the back part, which releases heat and condensation, faces outdoors.

Pros: Cost-effective and relatively easy to install for single-room cooling. More efficient than portable units of comparable size. Don't take up floor space.

Cons: Blocks a portion of the window, obstructing light and views. Can be noisy, especially older models. Not ideal for very large spaces or cooling multiple rooms.

Best For: Cooling single rooms or small apartments. Ideal for renters or those on a budget who need effective cooling for a specific area.

Ductless Mini-Split Air Conditioners (Split Systems): These systems consist of an outdoor unit (condenser/compressor) and one or more indoor units (evaporators) connected by refrigerant lines and electrical wiring, without the need for ductwork. Indoor units can be wall-mounted, floor-mounted, or ceiling-mounted (cassette).

Pros: Highly energy-efficient and quiet because the noisier components are located outside. Allows for zoned cooling, meaning you can cool individual rooms or areas independently, saving energy. Versatile in terms of indoor unit placement. Good for homes without existing ductwork.

Cons: Higher upfront cost than window or portable units. Professional installation is required.

Single Mini-Split (one outdoor unit, one indoor unit): Best for cooling a single, specific room or area where ductwork isn't present or desired, such as home additions, sunrooms, converted garages, or older homes. Can effectively cool medium to large rooms.

Multi-Split System (one outdoor unit, multiple indoor units): Ideal for cooling multiple rooms or zones in a house or office where each space requires individual temperature control. Suitable for homes with multiple bedrooms, or small offices.

Central Air Conditioners (Ducted Systems): A whole-home cooling system that typically consists of a large outdoor unit (condenser) and an indoor evaporator coil connected to a network of ducts that distribute cooled air throughout the entire building.

Pros: Provides uniform cooling throughout the entire home or commercial space. Quiet operation indoors as the main components are outside. Can be integrated with existing HVAC (heating, ventilation, and air conditioning) systems.

Cons: High upfront cost for installation, especially if ductwork needs to be added. Less flexible for zoned cooling compared to mini-splits, as all connected areas receive cooling.

Best For: Cooling entire large homes or commercial buildings where consistent temperature and airflow are desired across multiple rooms or floors. Most common in new constructions or major renovations where ductwork can be easily installed.

Through-the-Wall Air Conditioners: Similar to window units but designed for permanent installation through a pre-cut opening in an exterior wall.

Pros: Don't block window space. Often quieter and more secure than window units. A good long-term solution for single-room cooling.

Cons: Requires a hole to be cut in the wall, making installation more involved than a window unit. Less portable.

Best For: Suitable for apartments, condos, or older homes where window units are not allowed or desired, and central air is not an option. Good for cooling individual rooms.

City Plumbing offers portable air conditioning units from as little as £240 to £440. Portable air conditioning units are the most affordable choices and flexible for use in and around the home and require no installation.

Air conditioner size is measured in BTUs (British Thermal Units). An undersized unit will run constantly and struggle to cool, while an oversized unit will cool too quickly without effectively dehumidifying, leaving the room feeling clammy.

Consider your room size and use a BTU calculator to determine the air conditioner size best for your space.

Yes, air conditioning units do dehumidify. A core part of their cooling process involves drawing warm, humid air over refrigerated coils. As the air cools, the moisture in it condenses into liquid water, which then drains away through a condensate pan. This process effectively removes humidity from the air, making the room feel cooler and more comfortable, even if the temperature hasn't dropped drastically.

The lifespan of an air conditioning unit depends on its type, usage, and maintenance. Traditional split/central air conditioning systems generally last 15 to 20 years in residential settings. In commercial buildings with higher usage, this might be closer to 10-15 years. Portable or window units typically last around 8 to 12 years while internal water-cooled air conditioners can last longer, from 15 to 25 years, especially in commercial properties.

The running costs of air conditioning units vary based on the type of unit, its energy efficiency (measured by SEER/EER ratings), room size, insulation, and your local electricity tariffs.