The California Energy Commission voted 5-0 Wednesday, May 9, to adopt new energy building standards requiring solar panels for virtually all new homes built in the state starting in 2020.
The current 2016 Title-24 Building Energy Code Standards contains new indoor ventilation requirements. California has adopted the residential standards of ASHRAE 62.2 All low-rise residential buildings must have a whole house ventilation system that provides a calculated minimum amount of outdoor air by using either a continuously running bathroom fan or a supply or return air ventilation thru a central HVAC system. The minimum ventilation volume must be a minimum of 1 cfm for each 100 sq. ft. of floor area plus 7.5 cfm for each occupant. The number of occupants is determined by multiplying the number of bedrooms and then adding one. For example a 3 bedroom, 1,800 square foot townhouse would require 48 cfm of continuous ventilation. Additional calculations are required if the fan will be running intermittently thru-out the day as the fan will need to provide a larger airflow when running.
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Broan has introduced a bathroom fan/smart switch system that meets this requirement. It keeps track of the total usage of the fan thru-out the day and if fall short of the required number of air changes it will automatically turn on and run until the required airchanges have been satisfied. It also meets the maximum sound level requirement at 0.70 sones. It also coordinates with other fans normally installed in the house, such as the range hood to meet the calculated minimum cfm required. This new requirement takes effect January 1, 2010 when California adopts the 2008 Title-24 Building Energy Standards.
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On May 1, 2017 Santa Monica became the first city to adopt zero-net energy (ZNE) requirements. The State of California is planning to implement such a code state-wide but this will not be implemented until the 2020 T-24 code cycle so Santa Monica is out in front with net-zero.
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The basic premise of ZNE requires projects to generate enough of their own energy from renewable energy sources (solar PV for example), to equal what they use from the utility grid over the course of a year. For now this requirement only applies to new residential projects, not additions or alterations.
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However the ZNE requirement is parallel to the city’s Energy Reach Code which requires all new low-rise residential projects to be designed to use 15% less energy than the allowable energy budget established by the 2016 California Energy Code (Title-24). This presents some challenges as projects that may comply with the reach code (15% better than T-24) may not comply as a ZNE project. Conversely projects that can demonstrate ZNE compliance may still fall short of the 15% better than T-24 energy use. One does not always equal the other.
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This new code update became effective May 1, 2017. This emphasizes the importance of getting your Title-24 Energy Consultant involved in your project early in the design process as most projects will struggle to comply and will involve a lot of back and forth as different design and energy saving strategies are modeled, tested and revised to get the project over the finish line cost-effectively.
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Link to detailed ZNE and Reach Code explanation
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