When considering a year cycle, relying on hybrid ventilation (mechanical ventilation in cold periods and natural ventilation in warm periods) is more energy-efficient than using mechanical ventilation all year long. This remains true in warm, moderate, and cold climates.
Hybrid ventilation combines the best of both worlds: good winter energy performance and mechanical ventilation with heat recovery, and good summer performance with natural ventilation. The purpose and structure of a building will dictate what ventilation components to include and how the potential for hybrid ventilation can be harnessed.
A ventilation strategy will need to consider the design of a commercial or industrial building, internal thermal loads, the positioning of rooflights and windows, and the impact solar gains have on temperature. Through the understanding of structural design and building usage, ventilation can be introduced in the most cost-effective manner. This allows building owners and architects to make more informed decisions when choosing a natural, mechanical or hybrid ventilation system to improve indoor air quality.
Important factors to consider include:
Thermal comfort
Ease of operation
Safety of building occupants
Maintenance staff with access to roof windows, skylights or rooflights
Fire and regulatory standards
Use and shape of a building