About Hybrid Ventilation

Hybrid ventilation incorporates natural ventilation with traditional mechanical systems, all while reducing energy consumption, providing a healthier indoor climate, and reducing CO2 emissions.

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What is Hybrid Ventilation?

Mixed mode ventilation or hybrid ventilation is a relatively new concept that is a sustainable and cost-effective way to provide thermal comfort to occupants by regulating the indoor temperature. This ventilation strategy not only offers a means of indoor climate control, but also enhances indoor air quality by lowering CO2 levels, creating a healthier indoor climate, and improving occupant productivity.

Mixed mode ventilation systems combine all the best features of natural ventilation by controlling building openings automatically and intelligently with window actuators and a mechanical system.

Hybrid ventilation or Mixed Mode Ventilation?

These terms are used interchangeably to mean the same thing! So, the same principles and benefits that we describe about mixed mode ventilation are the same for hybrid ventilation.

How do hybrid ventilation systems work?

Hybrid ventilation systems reduce energy consumption through the reduction of mechanical fan use and, in some cases, the cooling demands. By using key natural ventilation strategies to ventilate during the day or night (night cooling), mixed mode ventilation reduces the use of mechanical systems and possibly the size of the system. Like natural ventilation systems, hybrid ventilation systems utilize sensors to monitor indoor temperature, CO2 levels, and humidity, as well as outdoor conditions. Based on this data, the system will automatically either chose natural ventilation or mechanical ventilation depending on which system is the most optimal to use. The system will then switch back to the natural ventilation strategies when appropriate. For example, if the weather is too cold, too rainy, or too hot, the mixed mode ventilation system adjusts the building openings appropriately and communicates with the mechanical ventilation system to optimize the indoor environment. The system, then, takes a holistic approach to ensure occupant comfort and indoor climate health for a high-performance building.

Hybrid ventilation

How does hybrid ventilation work in the different seasons?

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    Summer time

    Window actuators control building openings to let cool outdoor air into the building. This is often achieved through night cooling. Depending on climate, the building openings may also open during the day to change the air or cool the building, depending on indoor temperature parameters. These strategies ensure sustainable building operation through a minimum use of energy.

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    Winter time

    In some climates, a mixed mode ventilation strategy can work with a mechanical ventilation system to ventilate the building while recovering heat generated in the indoor environment. In this way, heat recovery can reduce heating demands while minimizing or eliminating the experience of draft.

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    WindowMaster mixed mode ventilation systems are intelligent indoor controls that monitor indoor and outdoor climate factors to deliver optimal indoor comfort. The climate can vary greatly during these seasons, so a combination of summer/winter strategy is often employed. The control system chooses between natural ventilation or mechanical ventilation, depending on what is most appropriate for both the indoor and outdoor conditions.

What types of buildings are suitable for hybrid ventilation?

Mixed mode ventilation is suitable for almost all building types, like office buildingsschools, shopping malls, hospitals, and sport facilities.

Why choose hybrid ventilation?

Because it’s a highly-effective indoor control strategy for sustainable buildings

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    Reduced costs

    Mixed mode ventilation is shown to save up to 25% in energy consumption compared to natural ventilation, and a whopping 60-70% in comparison to purely mechanical systems.

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    Low maintenance

    Mixed mode ventilation does not require costly maintenance, further reducing costs as well as saving you time and effort.

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    Improved air quality

    Mixed mode ventilation systems ensure that air is flowing into your building when appropriate. This will improve your air quality which, in turn, will improve the health of the occupants of the building and increase productivity and concentration levels.

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    Mixed mode ventilation ensures that each room is supplied with the right amount of both cool and warm air, keeping the temperature constant and at a pleasant level. This reduces or eliminates the feeling of drafts by occupants.

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    Reduced carbon emissions

    By implementing a mixed mode ventilation system in your building, you’ll also be doing your bit for the environment.

How can you determine if this ventilation strategy is right for your building?

The team of engineers at WindowMaster’s Ventilation Institute understand the design and commissioning for whole building controls and intelligent facade solutions. They can assist you in your project with simple advice or even detailed analysis such as CFD calculations and dynamic simulations of your building’s indoor climate. Our team has many years of experience in designing systems for both new-build and refurbishment projects all over the world, as well as carrying out post-occupancy evaluations through research and development projects.

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Jannick K. Roth


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