What is the difference between ventilation and air conditioning?

Ventilation and air-conditioning are two installations mounted in houses and other residential buildings, in industrial buildings and public buildings. Although both have similar functions and are often confused with one another, in reality, they operate on a slightly different basis. They also have different functionalities and give different outcomes. What are these two systems and what is the difference between ventilation and air conditioning?

Ventilation and air-conditioning – air treatment systems.

Ventilation and air-conditioning systems are installed in different buildings in order to treat air. Both improve its quality, contributing to a healthy environment at home. Perhaps that is why people outside the industry often confuse these two installations. They treat them as a single system with two names which they use interchangeably. However, there is a difference between ventilation and air-conditioning in both the mode of operation and their effects.

Air conditioning and ventilation systems and the law.

The main distinction between these systems lies in their governing legal conditions. Ventilation is mandatory in each building, regardless of its size or purpose.

In contrast, air-conditioning is not required by law. However, there are buildings where the installation of air conditioning is not only a matter of comfort, but a necessity. Examples are production halls where the operation of machinery or technological processes significantly increase air temperature. Air conditioning also requires so-called clean rooms. 

How does air conditioning work compared to ventilation?

Ventilation and air-conditioning are intended to improve indoor air quality and ensure greater comfort. However, each of these systems achieves this goal differently. Therefore, these mutually complementary systems are both used to achieve optimum conditions. Therefore, one can often run across the term ventilation-air conditioning installation.

Operating principle and functions of ventilation

Ventilation is an air treatment system which is responsible for its continuous exchange. This allows harmful products from the combustion of solid fuels and/or carbon dioxide emitted by humans to be evacuated. Used air is replaced by fresh, clean, and oxygen-rich air. In its simplest version, i.e. gravitational ventilation, air is exchanged only, without being modified. Therefore, the design of such ventilation systems is very simple and limited to several basic elements. Gravitational ventilation has been installed in buildings for centuries, although in primitive and less comfortable forms. In its oldest version, gravitational ventilation consisted of openings in the roof or in the upper part of the wall.

In modern ventilation systems, there are various improvements that boost its efficiency. They are necessary because the buildings currently built are airtight. As a result, the vacuum, or so-called draft, is not created in the system. To get rid of this problem, fans are used which force an adequate flow of air. 

Operating principle and functions of air conditioning

Air conditioning, in contrast to ventilation, does not cause the exchange of air into fresh air. Its task is to alter air parameters - i.e. to treat it. Indoor air is subject to such constant modifications. Using various equipment and devices, the air conditioning system:

• Lowers or raises indoor air temperature,
• keeps the temperature level steady,
• changes the air humidity level by drying or moisturizing it,
• purifies air by removing physical particles – from dust bits to micro-organisms.

Modern air conditioning may also have a heating function. It can therefore be used throughout the year. In the summer, when outdoor temperatures are high, the system cools down indoor air by evacuating heat outside the building. In the winter, when it’s cold outside, the system is used for heating.  

Ventilation and air-conditioning - differences.

The above descriptions show that there is a significant difference between ventilation and air-conditioning. It is primarily about function and the results achieved. Different auxiliary or control devices are used in either system. Characteristics of the systems:

• ventilation supplies fresh air and air conditioning usually forces circulation of current air,
• air conditioning stabilizes air temperature whereas ventilation changes temperature depending on the weather (except for ventilation with heat recovery),
• air conditioning may control the air humidity level, ventilation does not affect this parameter,
• air conditioning always purifies air using filters, whereas gravitational ventilation has not effect on air purity.

Modern ventilation and air-conditioning – not so different anymore. 

There will always be differences between ventilation and air-conditioning, for example in that one exchanges air, and the other does not. At the same time, continuous efforts to improve the comfort of everyday life have forced ventilation equipment manufacturers to add new functions. As a result, modern ventilation can also filter air. If it is equipped with a recuperator, it will recover heat during gas stream exchange, thus guaranteeing stable room temperature.

The best option is to integrate both systems into one installation so that they complement each other.

Remember that, when the air conditioner is on, no air handling unit without heat / cold recovery should be working. In the summer, warm air supply would force the air conditioner to operate with higher intensity, generating higher maintenance costs. A similar situation will occur in winter when air conditioning will be switched to heating.