London is braced for the hottest day of the year this week as the mercury rises up to 35C according to London24 (read the article here).

So how does you air conditioning system work to help through the hot times?

Many of us take our air conditioning for granted and indeed why should we worry all the while we are being kept cool in the summer and warm in the winter. It is an interesting subject and the principles also apply to your home refrigerator too.

The Basics

An air conditioning unit is in simple terms is a mechanism that shifts heat from one place to another. The unit will extract warm air from the environment in a home or office and shift it to the outside of the building. Strangely while you may stand close to a vent and feel as though you are being cooled, in fact it is the heat energy being removed that causes the temperature drop and not the other way round of cool air being pumped into the space.

Refrigeration

The central core of an air conditioning unit is the refrigeration cycle. This cycle is a sequence of changes to temperature, state (liquid to vapour) and pressure that the important refrigerant is going through as your air conditioning system works away extracting warm air from the atmosphere in the building. Refrigerant is a fluid that deviates between liquid and vapour at the right temperature for extracting hot air and pushing it through to the outside air. The refrigerant travels through copper pipes; one is insulated and one is not and it is these pipes that connect the indoor part of your air conditioning system to the outdoor part.

Most homes and offices use the common type of system – the split system, also known as an air source system as it removes heated air. It is known as a split system as there is an outdoor unit and an indoor unit. The refrigeration cycle is common to many kinds of air conditioning system.
There are 4 different stages to the refrigeration cycle from start to finish and it can be clearly seen how essential it is to have a well maintained system.

Heat Extraction

The interior part of the air conditioning system contains a blower that extracts air from the building and pushes it over an extremely cold coil. The coil is so cold because of the refrigerant running through it, so the air moving over the coil also becomes very cold. After the air has passed over the cold coil, the air temperature will drop markedly. If the room thermostat is set to 24 C, the air will be around 12 C if the system is working optimally.

The simple physics are that heat flows from warmer to cooler, we all know heat rises in a home and a similar principle applies. Once the warm but cooled air reaches the outdoor unit, it flows into the compressor which raises the temperature of the refrigerant so that it will flow out into the atmosphere. Unless the temperature was raised, the air would not be expelled from the air conditioning unit as cooler air will not flow into warmer air.

Obviously, if outdoor temperatures are exceedingly hot, the compressor has to work even harder to raise the temperature of the air until it exceeds the outside temperature. You will often hear air conditioning unit’s compressors working overtime in extreme conditions, the same way you can hear the compressor on your domestic refrigerator working, especially in hot weather.

There is another step in raising the temperature of the air to be expelled after the compressor has done its job. The air passes over another coil, this time increasing the temperature further and finally expelling the air that was originally extracted from the building.

Once the heat flows out of the refrigerant it condenses back to liquid and rapidly drops down to a low temperature again and the process repeats itself.

This is just a simple explanation of how an air conditioning unit and system works. It applies the laws of simple physics and as can be seen from the process, it is essential to keep the air conditioning system well maintained so that it can perform the job it is designed for in an optimum way.

Make sure you get the sun cream out and be sure to carry water with you this week as the heat wave arrives in London!

Air Conditioning Services London

Simply Air Conditioning London installs, services, and repairs air conditioning systems for homes and businesses across London. Contact us for a free quote.

• Air conditioning installation London
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• Home air conditioning installation — ready before the next heatwave
• Air conditioning maintenance and annual servicing

Tropical continental air mass waded in to London yesterday to give us temperatures as hot as those felt in the sunny climes of Portugal!

The South East of England in particular had temperatures 10 degrees higher than the average UK temperature for May.

We have seen the trend of rising temperatures in recent years as the global climate alters. The effect has been a massive rise in the amount of people contacting us for air conditioning needs.

Read more from the report in yesterday’s London24 News.

Air Conditioning is relied upon worldwide to provide comfortable living for people that live in many different climates. The quality of life during extreme periods of weather often depends on the type of air conditioning system installed within a building or individual room. These days more and more people are relying on air conditioning even in temperate climates for the additional benefits and savings a whole packaged air conditioning system can offer. There are many different types of air conditioning installation and this article describes the various installations available and the particular qualities each brings.

Air conditioning may refer to whole systems, single devices or portable units. All types of air conditioning work by extracting warm air and through a refrigeration process expel cool air back into the living or work space. This is a simple explanation of the process, and as will be seen, the process can also be reversed with some types of appliance to extract cold air and heat it up thus providing warm air to the living or work space. Air conditioning provides added value in that it provides a consistently good air quality and ambient temperature and may have filters that enhance air quality by removing, pollen, mould spores, dust smoke and other pollutants and allergens. Air conditioning reduces humidity in the atmosphere which helps to prevent mould and condensation.

Window Air Conditioning Units

This type of unit is designed to cool small areas such as an apartment living room or bedroom. They have the advantage of being affordable and easy to install as well as economical to run. They are not as efficient as other units but as can be seen worldwide, these units are extremely popular for apartment dwellers. Window units are installed in open windows and internal air is blown by a fan over an evaporator. External air is drawn in over a condenser and cooled before being blown into the room area.

Portable Air Conditioning

This type of air conditioning unit is often seen in homes or offices where occasional use is required during extreme weather. Many non-air conditioned office buildings hire portable units if they are caught out by soaring temperatures. These units are plugged in where they are needed and can be moved around.

Portable Split System

This kind of unit has an indoor unit on wheels that can be moved around and connected up to an outdoor unit

Hose System

Hose systems, are either air-to-air monoblock. The air-to-air type is vented via a hose to the outside usually through a window where water is discharged. The monoblock type is useful if a window is not available as water collects in a container. When the container is full, the unit cuts out until the water is emptied.

Evaporative System

This type of cooler uses a different method and is useful because it does not require a hose. Instead, water is evaporated on cooling fins releasing the cooled vapour into the atmosphere.

PTAC (Packaged Terminal Air Conditioner)

This kind of system is alternatively known as a ductless wall split air conditioning systems. Systems of this kind are often seen in hotels and other large buildings. The system has two units an internal evaporator and external condenser connected through a wall. This allows for many different areas to be temperature controlled and may be installed in existing buildings with the minimum of disruption. The same units can also be used to provide heating during the colder months.  

Central Air Conditioning

Central air conditioning is a large device that controls the air temperature throughout a building via a network of return and supply ducts. There are two types of central system, packaged and split.

Packaged System

This air conditioning system has all components (evaporator, condenser and compressor) integrated into one cabinet which is sited on a roof top or next to the building. The packaged system can include components for heating the building also. The system of ducts supplies the ambient air to each sector of the building and may be thermostatically controlled in different parts of the building.

Split System

A split system has an outdoor unit containing the condenser and compressor and the evaporator is contained in an internal unit which may also include a heat pump for winter use.

Different buildings and requirements call for different types of air conditioning systems. It is important to consult a qualified contractor to help avoid the common pitfalls that can happen when selecting an air conditioning system.

When we step into an elevator or lift, we give very little thought to them, apart from ensuring we have selected the right floor button for our destination. Usually not much attention is paid to the environment, but it could well be a different story if air conditioning for elevators was not present. Anyone who has been stuck in a lift will know how quickly the temperature can rise to unbearable heat or cool to freezing depending on time of year and exterior temperatures.

Elevators and lifts transport people and goods between the floors of a building. The earliest type of elevator is accredited to the Romans namely Vitruvius, an architect. The use of these devices in the ensuing years was for moving things rather than people using a system of rope hoists powered by animal, people, or water.

The first true passenger elevator was invented by Elisha Otis whose name is famous today with over 20% of market share belonging to Otis lifts and elevators.

As the world expands and urbanisation eats up land, lifts and elevators are essential to keep people moving; from modest two or three person lifts in a small office or store to the super express lifts that soar up thirty or forty stories or more leaving the passenger’s stomach on the ground floor. A major concern is to keep people comfortable while using elevator cabs where they are often in close proximity with other people. Depending on passenger traffic, it could be quite squashed in at times.

Air conditioning for elevators and air conditioning for lifts therefore, is an essential requirement to keep an ambient temperature and to circulate fresh air in the confined space of the cab. In general terms, air inside a lift tends to mirror the external environment, particularly when it is situated on the outside of a building such as the magnificent lift outside Lloyds of London. Often lifts and elevators go below ground such as in multi storey car parks or basements. For this type of device, air conditioning for lifts is not a luxury but essential for the comfort of passengers.

Air conditioning for lifts and air conditioning for elevators ensures the cab will be cool in summer months and warm in the winter time, keeping fresh air circulating. The air conditioning for lifts should not be a marked difference to the building temperature. Air conditioning for elevators can be remote controlled in many instances by the building facilities management team, keeping the air stable.

There are obviously pros and cons to air conditioning for elevators and air conditioning for lifts and next, we take a look at how an accredited air conditioning engineer deals with them.

The air conditioning of elevators causes heat from the cooling process to dissipate into the lift shaft. The lift cab is not air tight so some heat can return into the cab reducing the cooling effect.

Energy

Air from the building leaks into the lift shaft as the elevator moves and obviously there is independent ventilation in the lift shaft. While this in situ “air conditioning” will not incur energy cost, a specific air conditioner designed for an elevator will achieve better overall control of the temperature inside the cab, although energy cost is attached to this.

Condensation

Any air conditioning for lifts has to deal with the condensation issue. The condensed water that is produced by the air conditioner needs to be disposed of or else there would be flooding in the cab and lift shaft.

Methods of removing condensed water

There are at least four ways to remove condensed water from the air conditioner. However, each solution has its pros and cons.

Atomizing

The best way to cope with condensation from air conditioning for lifts is Atomizing. This method sprays fine water droplets on the hot coils of the unit ensuring condensed water quickly evaporates. While this is the ideal method to dispose of the condensation, it can be more expensive than other methods.

Boiling

Collected condensation is heated to above boiling point which causes evaporation. However this uses a lot of energy.

If you have a hot stuffy lift or one that is not comfortable for passengers, it is quite easy to retrofit an individual air conditioning unit at an affordable price. Our engineers are expert professionals who will guide you through your choice of unit, to installation and commissioning.