General Questions

An air-conditioner works similar to a refrigerator. The refrigerant flows through the system, and changes in state between liquid and gas. During the typical refrigerant cycle there are four main processes:

1. At the heart of all conditioning units is a compressor, which pumps the refrigerant around the system. Before the refrigerant reaches the compressor it is in a gaseous state at low pressure. Due to the actions of the compressor, this gas is heated, compressed to a high pressure and travels to the condenser.

2. Once the high-temperature, high-pressure gas reaches the condenser it releases its heat to the outdoor environment and becomes a cold, high-pressure liquid.

3. The pressurised liquid travels through an expansion valve to reduce its pressure, resulting in a cold, low pressure refrigerant liquid.

4. This cold, low-pressure liquid finally flows to the evaporator where it absorbs heat via evaporation from the indoor air and becomes a low-pressured gas. The gas then flows back to the compressor and the cycle starts all over again.

The human factor
As each person produces around 120 Watts of heat the number of people in a room directly affects the cooling capacity needed.

Electrical equipment
Computers and other electrical equipment are continuously producing heat, increasing their running temperature and therefore reducing their efficiency. A room with a high density of electrical equipment e.g. a server room will need a higher cooling capacity than a room of the same size with no electrical equipment

The cooling capacity for a room is calculated carefully by our engineers, a major factor in this calculation is the size of the room.
By having unnecessary ventilation the size of the room is essentially increased to include the outside environment.

This means the unit becomes underpowered, reducing efficiency drastically and increasing the likelihood of problems occurring.

There are three main methods through which heat travels from a hot environment to a cooler one:

Heat can travel in the form of a wave, transferring energy from one object to another..

Energy can also be transferred within an object and between objects in direct contact.

A fluid or gas can hold heat and transport it directly to another area.

All modern air-conditioning units now produced have inverter technology integrated into the outdoor unit.
The primary function of a converter is to only use the minimum power needed to keep the room at the required temperature.

For example, as the cooling capacity in the room increases, the inverter increases its capacity to maintain the necessary temperature.
A unit without inverter technology runs on an 'all or nothing' policy, there are no gradations. As a result, the unit is less efficient, less economic and worse for the environment.

Advantages of the inverter technology

  • The start-up time is reduced by 1/3
  • You save a lot of energy and also money : 30% less power consumption
  • Avoids cycling of the compressor meaning that there are no voltage peaks
  • No temperature fluctuations

A heat pump extracts the low temperature energy from the environment and funnels it to heat the internal area needed. Heat pumps are exceptionally efficient – just 1kW of electrical input is necessary for between 3 – 5kW of heating output.

In comparison, fossil fuel boilers only produce 1kW of heating power for every 1kW electrical input. It goes without saying then, that heat pumps are from 3 to 5 times more efficient at heating than fossil fuel boilers.

This efficiency has lead to increased use to heat homes cost-effectively, most notably in Scandinavian areas through their harsh winters.

Cold draughts associated with air conditioning are usually caused by poorly thought-out systems. During the design stage of the system, our engineers go to great lengths to ensure a system that minimises draughts for the personnel working close to the unit.

Manufacturers of air conditioning units usually assume the ceiling height on which the unit will be mounted Is between 2.7 to 3.5 metres.
With this in mind, the cold air emitted by the air conditioning unit is able to mix with the air of the room before reaching the working level for the personnel thus reducing any potential for irritating draughts

The systems that Air2hire sell, hire and install come with zero risk of legionella colonisation as none of them are water based. Dry based systems that we use contain no water in which a possible colonisation could occur.

Allergens are microscopic particles in the air that, if inhaled, can bring on an allergic reaction in the body.

They include:
  • Pollen
  • Dust
  • Diesel exhaust particles – DEP's
  • Volatile organic compounds – VOC's

Pollen and dust will always be present in small quantities in the office environment, it is the DEP's and the VOC's present in many synthetic products which companies must be focussed on reducing.

Especially in the city environment the DEP's and VOC's combine with the normal allergens present in the air to produce 'heavy allergens'.
These heavy allergens produced are particularly potent when inhaled and can produce flu-like symptoms, coughing and wheezing.