Our Guide To Air Conditioning

What does air conditioning do?

  • Cool – effectively and quickly
  • Heat – more efficiently so than conventional central heating systems
  • Regulate humidity – by controlling the amount of moisture in the air
  • Ventilate – providing a source of clean air in rooms with no windows
  • Filter – reducing the amount of dust particles, pollen and other contaminates circulating in a room for allergy sufferers

What types of system are there?

 TYPE OF SYSTEM  DESCRIPTION
 High Wall Mounted  Fixed just below the ceiling
 Low Wall Mounted  Fixed just above ground level similar to a radiator
 Floor Mounted  An upright rectangular box fixed to the floor
 Under Ceiling/Ceiling  Suspended  Fixed to a solid ceiling where there is no recess above it
 Floor and Ceiling  These can be fitted like a low wall mounted or an under ceiling
 Ceiling Cassette  Fixed into a recess in suspended hollow ceilings, flush with the roof
 Ducted  A concealed unit feeding air flow into ceiling/wall ducts

Most Popular?

The most common systems are ‘single split’ systems where one indoor unit runs to one outdoor unit. However, if climate control is required in more than one room then a ‘multi split’ system may be more effective which involves multiple indoor units all running to a single outdoor unit.

What size system do I need?

Systems are measured in Kilowatts (KW) and/or British Thermal Units (btu);

Table A

 KW  BTU
 2  7,000
 2.5  9,000
 3.5  12,000
 4  15,000
 5  18,000
 6  21,000
 7  24,000
 8  30,000
 10  36,000
 13  43,000
 14  48,000

Table B

 TYPE OF AREA  W/M2
 Residental  125
 Office  125 – 150
 Office – busy/with window  150 – 200
 Call centre  150
 Retail  125
 Comms/Server room  200
 Conservatory  300
 Doctor/Dentist  125
 Restaurant  150
 Gym  150-180
 Public area  125

There are many factors which will contribute to deciding on the size of unit a specific room will need. Below is a very basic formula to give you an idea;

Size of system = Room size x Wattage of cooling power required per square metre
(KW = m2 x w/m2)

NOTE: The height of a room isn’t a factor as some would imagine. This is due to the nature of hot air which rises, leaving the heavier refreshing cool air to sink into the room.

NOTE: 1 kw = 1000 watts

Example

A conservatory measuring 4 metres by 3 metres will, according to the formula, require a 3.6KW (3,600W) system.

4 metres x 3 metres = 12 square metre room size.

12 square metres x 300 watts of cooling power required per square metre = 3600 watts

Given that a Kilowatt is 1000 Watts we can divide 3600 by 1000 to give us 3.6KW

This is where the guide ends and we need to consider external factors. Imagine that the conservatory in question is in a family home and is used as a second living room by the children. There is a PC, a big screen TV (to which a games console is connected) and even though only two children live there they often have friends round. When you consider all these heat-generating elements we can assume that our cooling requirements will be higher than 3.6KW.

We can see from Table A that systems come in 3.5KW or 4KW sizes. In this circumstance it would be wise to opt for the larger system rather than ignore what the room is being used for and hope one just under requirement will be enough.

A bedroom measuring 3 metres by 2.5 metres will, according to the formula, require a 0.93KW (937W) system.

3 metres x 2.5 metres = 7.5 square metre room size.

7.5 square metres x 125 watts of cooling power required per square metre = 973 watts

Given that a Kilowatt is 1000 Watts we can divide 973 by 1000 to give us 0.97KW

Again, our guide has served us well up to this point but here is where we must think about the specifics of the room. What if the room in question had a large south facing window with only a thin curtain? This would absorb the sun’s rays all day throughout the summer months with nothing to block the heat.

When we consider that the smallest unit available is a 2KW our initial thoughts may be that it is too big for a room requiring a mere 0.97KW of required cooling but again, taking into consideration the large heat generating window, we can accept that a 2KW system will be exactly what is required.

What is inverter technology?

An inverter is used to control the speed of the compressor motor to allow continuously regulated temperature. In contrast older fixed speed compressor air conditioning systems regulate temperature by either working at maximum capacity or by being completely switched off.

Inverter powered air conditioning systems can set the speed of the compressor anywhere from full capacity to fully off depending on how much cooling power is required for the room. Because of this the air conditioning system can run consistently providing adequate cooling or heating whilst drawing just enough power to do so.

Eliminating stop-start cycles increases efficiency, extends the life of components, and helps eliminate sharp fluctuations in the load the air conditioner places on the power supply. Ultimately this makes inverter air conditioners less prone to breakdowns, cheaper to run, and the outdoor compressor is generally quieter than a standard air conditioning unit’s compressor.

Do I need an inverter system and if so which one?

In times of environmental responsibility and costly utilities, it has been necessary for the industry to evolve and embrace inverter technology which is why almost every single new system uses it. That said there are varying levels within this and each is designed for a specific purpose and budget.

  • Many manufacturers offer a standard inverter as a base model with regard to energy efficiency which is often the most inexpensive to buy. These are ideal for those who don’t want a system that is going to be used regularly where regular running costs aren’t going to be a concern.
  • Next there is a mid range system which is often the most popular. Whilst slightly more expensive than the standard inverter it is also more efficient which is reflected in the running costs.
  • Finally there is the top end inverter. This will inevitably be more expensive than the others but with regular use (i.e. cooling through summer and heating through winter) it will prove it’s worth when it yields the least energy consumption of the three.

Essentially it is how much use your air conditioning system will get that will dictate how much you should spend initially and in turn how much you will spend on energy bills. In short there isn’t a ‘best inverter’ but there will be a best inverter for you.

Every single system we sell on our website is listed with the whole specification straight from the manufacturer so you can compare all of them against one another to work out which one is best for you and your budget. Some things to look out for are;

COP – The ratio that measures the energy efficiency of the HEATING performance (the higher the better)

EER –The ratio that measure the energy efficiency of the COOLING performance (the higher the better)

Energy Label – Rated from A+++ down to G

Annual Energy Consumption – The lower the better.

 Energy Efficiency Class  SEER  SCOP
 A+++  8.50 >  5.10 >
 A++  6.10 < 8.50  4.60 < 5.10
 A+  5.60 < 6.10  4.00 < 4.60
 A  5.10 < 5.60  3.40 < 4.00
 B  4.60 < 5.10  3.10 < 3.40
 C  4.10 < 4.60  2.80 < 3.10
 D  3.60 < 4.10  2.50 < 2.80
 E  3.10 < 3.60  2.20 < 2.50
 F  2.60 < 3.10  1.90 < 2.20
 G  < 2.60  < 1.90

What does installation involve?

Essentially there will be an indoor unit (evaporator) and an outdoor unit (condenser). Between these will run two lagged copper pipes, a 3 core and earth power cable and a drain.

On a simple ‘back-to-back’ installation where the indoor unit and outdoor unit are adjacent to one another on the same wall this ‘pipe run’ will be minimal going straight through one hole.

In some circumstances it isn’t practical for a back-to-back installation so pipes may need to be run above suspended ceilings, through attics or across walls in specialist ‘trunking’.

If a ‘multi-split’ system where several indoor units all converge to run into one outdoor unit that has been installed, then a more complex network of pipe runs will be required.

Where the pipes from the indoor unit must run upwards the gravity drain will be rendered ineffective, therefore a condensate pump will be required to expel the condensate water.

In any case you can be sure of a professional and high quality finish to every project with each one given the same care and attention to detail.

Am I covered by warranty?

Of course. All of our installation work is covered by a minimum 12 months guarantee and all systems are covered by a minimum 12 months manufacturer’s warranty with some offering up to 7 years.

We also carry out annual servicing to ensure that your air conditioning systems operate more efficiently. Poor maintenance and dirty components can increase energy consumption by as much as 60%*.

At the same time our engineers can also check for potential defects and rectify them before they escalate into further problems. This is in keeping with manufacturer’s warranty terms who specify that systems must be regularly maintained by certified and trained professionals.