Commercial ventilation, how to adapt to the energy certificate?

The ventilation needs differ depending on the location and its requirements. What may be efficient for a residential building may have nothing to do with what is necessary in a house in a rural environment. However, it is in public places with a large number of people where the regulations can become more decisive. In what is known as commercial ventilation, which affects establishments ranging from hospitals to cinemas or shops.

This regulation on commercial ventilation is included in the RITE (Regulation of Thermal Installations in Buildings) and regulates how public and commercial spaces should be ventilated. It establishes the requirements for energy efficiency and safety that thermal installations in buildings must comply with.

These instructions in the RITE are essential to obtain what is known as the energy certificate. In the case of commercial ventilation, it is stated that it is necessary to have ventilation systems capable of providing sufficient outdoor airflow. In addition, it must prevent the formation of pollutants. In the case of residential buildings, this regulation is governed by the Basic Document HS3 of the Technical Building Code, while in commercial spaces the RITE is used as a reference.

The technical text includes a series of specific categories for each of the commercial spaces in particular. The categories range from more to fewer requirements and are classified as:

1. Indoor air quality IDA 1: optimal air quality. These are the specifications for hospitals, medical centers, laboratories, and spaces where children are present, such as nurseries.
2. Indoor air quality IDA 2: good air quality. The specifications are lighter and are to be followed in offices, common areas in hotels, residences, educational public spaces, libraries, and others.
3. Indoor air quality IDA 3: average air quality. The regulations for other spaces such as commercial spaces, hotel rooms, restaurants, and other dining establishments or sports centers and gyms.
4. Indoor air quality IDA 4: low air quality. This application level has no uses in any space that requires commercial ventilation.

The application parameters included in this category are essential to implement a ventilation system in a commercial building. The presence of particles must be eliminated, and air filters must be used in many cases. Minimum conditions of well-being, health, and hygiene must be achieved.

To comply with the RITE requirements in commercial ventilation, additionally, the Technical Instruction 1.1.4.2.3 details the minimum outdoor airflow for ventilation. The methods by which this flow must be calculated are also indicated:

• Indirect method for outdoor air flow per person.
• Direct method by perceived air quality.
• Direct method by CO2 concentration.
• Direct method for airflow per unit area.
• Dilution method.

Each method is more optimal for different specific situations. Nonetheless, the indirect method for outdoor air flow per person is the simplest to implement. In any case, the air quality is directly related to what is required based on the regulation. Sometimes it depends on the air conditioning system and other times independently.

How to improve commercial ventilation?

To implement a commercial ventilation system, many more factors must be considered. Practically, the following recommendations are given:

1. The ventilation system can be mechanical or natural. Hybrid methods can also be used. In any case, it is necessary to achieve a sufficient outdoor airflow, always depending on the needs of the establishment and its use. Contaminant concentrations must be stopped, and a minimum quality for the people present in the commercial space must be achieved.
2. Filtering the air before it enters the establishment is always an option to consider, especially in cities or densely populated areas where there is a lot of traffic or other contaminating agents. For this, air filters and other methods can be used to clean the air of impurities.
3. Depending on the conditioned airflow extracted by mechanical means, the installation of a heat recovery unit may be necessary. This would also reduce energy losses.
4. Commercial spaces often have excessive spending on air conditioning. It is always more than advisable to seek out energy-efficient systems. It should be noted that the European Union is moving towards nearly zero energy consumption new buildings. In commercial buildings, there are numerous options for saving on mechanical ventilation systems.

Complying with the RITE when installing commercial ventilation systems is essential to remain within the law and to guarantee the health and well-being of all users.