Reduce the consumption of your home using an energy recovery unit

Ventilation companies offer different options when it comes to installing a heat recovery unit in existing homes. The main advantage of a heat recovery unit is that it significantly reduces the energy consumption of households. Let's analyze in more depth the characteristics of this crucial component of building ventilation systems.

What is the purpose of a heat recovery unit?

According to the Technical Regulations for Thermal Installations in Buildings (RITE, 2007), in its register of documents recognized as public and informative Energy savings and recovery in air conditioning installations, "the heat recovery units of the extracted air in air conditioning systems allow maintaining adequate indoor air quality without penalizing energetically the systems of hygrothermal conditioning of supplied air to the rooms."

Types of heat recovery units

There are different types of heat recovery units used in ventilation and air conditioning installations, whose main mission is to recover the energy released by the air expelled from inside the building to the outside:

• Plate heat recovery unit.
• Rotary heat recovery unit.
• Heat pipes.
• Double water battery.
• External battery.
• Water loop battery.
• Active recovery by refrigeration circuit.

Whatever the equipment used, all enable the energy exchange between the air currents coming from the outside and the exhaust air currents. However, if an energy recovery system is not installed, an additional load loss will occur, resulting in an increase in the energy consumption of the fans, as they must maintain the same flow rates in circulation throughout the installation.

Ventilation systems: Individualized centralized MV and decentralized MV

To improve energy efficiency in existing buildings, one can choose between two ventilation systems (both incorporate a heat recovery unit): individualized centralized mechanical ventilation (for the entire home) or decentralized mechanical ventilation (one unit for each room in the home).

The Double Flow MV is a ventilation system that ensures air quality by extracting stale air from humid rooms (kitchen, bathrooms, toilets, and laundries) and simultaneously ensures the supply of filtered fresh air to dry rooms (living room, dining room, and bedrooms). Thanks to the core of the heat recovery unit, we can recover up to 95% of the energy from the expelled air.

Characteristics of individualized centralized MV:

• The intake of fresh air is done through a terminal located in the outer wall or through the geothermal air collector.

• The central unit recovers up to 95% of the energy from the extracted air, allowing preheating of the air supplied into the home.

• The air distribution networks allow optimal ventilation tailored to the needs of each room. Insulated ducts to reduce thermal losses and prevent condensations in the ducts.

• The supply outlets allow flow regulation for dry rooms. And the extraction outlets allow flow regulation for humid rooms.

• The expulsion of stale air is done through a terminal located on the roof of the building.

Characteristics of decentralized MV:

This is an ideal ventilation system for rehabilitation projects with little space available, as its installation is done on the building facade. The decentralized double flow MV works according to the principle of controlled supply and extraction of air in dry rooms, complemented by controlled extraction in humid rooms. The heat from the extracted air is recovered in the heat exchanger to heat the supplied air.

Main advantages:

• Allows air renewal of up to 70 m3/h.
• A single entry for fresh air intake and stale air expulsion.
• Suitable for rehabilitation projects.
• Removable exchanger for easier maintenance.
• Low-consumption motors.
• Exchanger with up to 80% recovery.
• Quiet and discreet.
• 100% by-pass for night cooling.