After a winter 2017-2018 long, gray and cold, spring is here and there!
The sunny days are coming back, the temperatures are rising and with them, the risks of heat wave or heat wave.
If it is rather easy to fight against the cold, protecting yourself from the heat is more difficult and the use of air conditioning techniques is almost compulsory in case of hot weather. This is especially valid for the most fragile people, such as babies or elderly people… We still remember the tens of thousands of premature deaths during the heat wave in France in 3! The use of air conditioners could probably have saved many lives!
What is an air conditioner? How does it work ?
An air conditioner works like a refrigerator…. except that it's an open air refrigerator (and you're in it)! It is a thermodynamic refrigeration circuit which uses the latent heat of evaporation and condensation to pump calories, ie heat, from one place to another.
A cold circuit consists of:
- of an evaporator, it is the cold part (this is called the cold source: the calories are "pumped" there towards the fluid of the fridge circuit, therefore the temperature of the evaporator drops)
- of a compressor, it is the engine of the refrigerator which will put under pressure and in movement the gas
- of a condenser, it is the hot part, the grid behind the refrigerator (this is called the hot source, the calories are "pumped" there from the fluid and that will cool and condense the gas and increase the temperature of the 'evaporator)
- a pressure reducer which allows the gas to regain volume after evaporation without increasing in pressure
An air conditioner is an "open" refrigerator fitted with two fans: one to supply cold air, the other to extract hot air! It's a bit like leaving the door open of your fridge and putting a fan in front of it ... Except that, in this case, as the removal of calories is done in the same room, the overall balance will be negative : the room will eventually heat up. For an air conditioning to work, it is therefore necessary to evacuate the calories to another environment, that is, most often, outside!
For this to work, the hot spring, that is to say the black radiator behind the refrigerator, should be located in another room, ideally outside in winter and in the cellar in summer. Obviously, in the case of domestic refrigerators, this does not exist, but professional cold rooms all have their hot source (condenser) outside, just like stationary air conditioners.
Reversible air conditioning and dehumidification
When the circuit can be reversed, then we speak of a reversible air conditioner which makes it possible to heat up instead of cold in the "useful" room. More commonly, this is called a heat pump. A refrigerator is therefore a heat pump, like all air conditioners that use a compressor. Indeed, there are other cold circuit technologies such as, for example, cold by adsorption or absorption.
Finally, many heat pumps or air conditioners also have an integrated dehumidification function. A dehumidifier is therefore also a refrigeration circuit adapted so that the cold part (evaporator) is constantly below the rosé point (condensation point of the ambient air)
In summary, an air conditioner can therefore:
- make cold,
- make warm (if reversible)
- dehumidify the air in a room (if the model allows it).
Now that the theory part is done, let's move on to practice. How to choose a mobile or fixed air conditioner?
Mobile or fixed air conditioners? Comparative advantages and disadvantages of both types of air conditioning.
An air conditioner is chosen according to its cooling capacity in Watts. Each manufacturer gives indications in relation to the volume and / or the recommended surface. Count around 150 Watts per m² to get good cooling power. Quick comparison between fixed air conditioners (wall mounted with an external battery) and mobile air conditioners (on wheels)
A portable air conditioner will therefore bring you freshness wherever you want and at a lower cost. However, its main disadvantage is to have a hot air exhaust via a flexible pipe (supplied) which can be unattractive.
Its main advantage is its high mobility and low price, both purchase and installation!
To go further and if you have questions about an installation: visit our website forum on thermal comfort