Ecovent Hybrid - EVH

School ventilation

New guidelines for air quality in classrooms point towards a change in approach to ventilation within schools. Building Bulletin (BB101 2016 draft) have introduced Hybrid, in addition to Mechanical and Natural, ventilation strategies which can meet the thermal comfort and indoor air quality guidelines within schools.

Hybrid ventilation systems use a combination of automatic mechanical ventilation and manually operated windows to achieve classroom comfort conditions. These conditions are maintained by supplying a variable volume of fresh air to manage room CO₂ and temperature levels.

Preliminary findings from using a Hybrid ventilation approach, such as in the Priority Schools Building Programmes, have made it the preferred method for ventilating classrooms.

Ecovent Hybrid Features and Benefits

• Our Hybrid units are energy efficient, with low SFP to help achieve L2 Building Regulations.
• They are equipped with EC fans, offering maximum energy efficiency and minimum energy consumption. Fully controllable and ErP Lot 11 compliant.
• The premium acoustic insulation, built into each unit, helps ensure the requirements of BB93 and OS are met.
• The Hybrid unit operates by regulating fresh and recirculated air, controlling the CO₂ and temperature, balancing comfort and air quality. There is a controls philosophy detailing the full operation available upon request.
• LPHW (Low Pressure Hot Water) coils ensure that the air being supplied is no lower than 5°C below the room temperature setpoint, meaning that air quality can be maintained through colder periods whilst eliminating the potential for cold draughts.
• Each unit comes with simple user interfaces, identifying the current operating mode. These controls come with a manual override, to control CO₂ levels and summer overheating.
• Units are of slimline, lightweight construction, saving space and easing installation. Because the units are located on a single wall or facade, this negates the need for ventilation stacks or ducts, reducing installation time and costs.
• Options for the units can include: alternative spigot connections, bespoke casework colours (standard is RAL9010 pure white), non-painted galvanised finish and internally mounted valve and actuator kits.
• Room units are available in 3 sizes. Any of these units can be combined to achieve the required duty. This enables ideal room placement to give the best ventilation coverage.
• For larger spaces, such as gymnasia, a roof mounted unit is also available. The two part EVHR474 features a weatherproof external turret and a room-side fan section, where the mode of operation is the same as the room mounted unit.

Operating modes (from top to bottom)

Full fresh air mode: Designed to reduce higher CO₂ and hotter temperature levels. The mixing damper is closed; allowing no re-circulation.

Fresh air mixing mode: For higher CO₂ levels. Cooler outdoor air is mixed with recirculated air, where the ratio of fresh air is modulated to control temperature and CO₂.

Full re-circulation mode: With fan running for colder conditions. The mixing damper is fully open, allowing air to be extracted from the space and passed over an LPHW coil for heating.

Full natural mode: Using window opens. unit shuts down, with windows open, allowing for natural ventilation.

VES has a comprehensive range of Hybrid ventilation units. The range enables the use of hybrid ventilation strategies to be used in multiple areas within a school building. Room units are available in 3 sizes and can be combined to achieve required duties. By doing so, ideal room placement can be achieved to give the best ventilation coverage. For larger spaces, such as a gymnasia, a roof mounted unit is also available.

The two-part EVHR474 features a weatherproof external turret and a room-side fan section. The unit’s operation and flexibility is the same as the room mounted unit.

To get a better and more detailed understanding of the Ecovent Hybrid ventilation unit, you can view our Ecovent Hybrid brochure.