To design a carbon-neutral building, consider the following strategies:
- Design the building form, mass, and openings to take full advantage of natural ventilation and daylighting opportunities.
- Use electric lighting only in spaces where the natural light is insufficient and during hours without sun.
- If possible, make use of ceiling fans. With an air movement of about 150 fpm (1.7 mph), a person will experience the same level of comfort with the air temperature 3-5°F higher than a space without air movement.
- Incorporate thermal mass and evaporative cooling if appropriate for the weather and building use, and only use compressor cooling as a back-up or on design days.
This effort requires coordination between the architect, the mechanical engineer, and, if window sensors are included, a controls contractor. Include the owner in the effort if the definition of comfort is to be explained and discussed.
It is more challenging to predict and design for comfort in a mixed mode or naturally ventilated building than it is to specify rooftop units that are sized to keep a space at 74° F.