Dedicating regional efforts towards Dedicated Outdoor Air Systems


What are Dedicated Outdoor Air Systems?

Commercial buildings require outside air whenever a space is occupied to meet ventilation standards and maintain indoor air quality. Dedicated Outdoor Air Systems (DOAS) are mechanical equipment systems that provide outside air to offices, conferences rooms, corridors and many other types of spaces in buildings separately from heating and cooling these spaces.

Many traditional mechanical systems for heating and cooling include  ventilation as part of their function. The idea of mechanical equipment being able to heat, ventilate and air condition (HVAC) sounds like the equipment is the jack of all trades, but in reality is the master of none. Often the system has to provide full capacity airflow to meet the ventilation needs of the space even when heating or cooling is not needed.

Decoupling ventilation from space heating and cooling offers the opportunity for significant fan energy savings. Washington State approved code language in the Washington State Energy Code (WSEC 2015) providing prescriptive requirements for Dedicated Outdoor Air Systems (DOAS) for certain building types for new construction.

These new HVAC requirements will bring efficient HVAC design strategies for buildings into the state beginning July 1st of 2016, but with a one-year delay in implementation to accommodate industry education.  So, although the 2016 Washington Energy Code becomes effective on July 1, 2016, DOAS becomes effective on July 1 2017.  

What does this mean for the market?

The alliance will provide funding to develop education and technical support for the DOAS beginning in early 2016 to ensure market understanding of practices before the adoption of the code. NEEA will also continue to provide funding to develop education and technical support for  other new energy code requirements as well. NEEA has also submitted a proposal to strengthen the language of DOAS in the 2018 International Energy Conservation Code Option Path. 

NEEA's codes and standards experts participate in the Washington State Energy Code Process to advocate for code measures that save energy and make sense for the market place. New energy code requirements are generally based upon current market practices but may not have awareness among all contractors, engineers and architects. To increase market adoption and increase compliance with the energy code, the region helps fund organizations such as the Northwest Energy Efficiency Council (NEEC) for the commercial energy code and Washington State University Energy Extension (WSU) for the residential energy code to provide educational training sessions on envelope, mechanical and lighting system requirements of the energy code. 

So far in 2015, the alliance has funded ten commercial code training sessions on the 2012 Washington State Energy Code. We offer these training sessions at multiple locations throughout  Washington State at no cost to participants. In addition to these trainings, we help fund code hotlines supported by NEEC and WSU for contractor, engineer and architect assistance in understanding application of the Washington State Energy Code.

The implementation of DOAS systems as a prescriptive measure  in a subset of newly constructed buildings present the opportunity to save energy in mechanical HVAC systems across the state. Buildings implementing DOAS mechanical systems in which the ventilating function for the building is separated from the heating and cooling function is nothing new, but other, many times less efficient, HVAC systems continue to dominate the market.  The ability to design and install combined ventilation, heating and cooling HVAC systems will remain in the subset building types but it will need to be demonstrated that these systems make sense for the proposed building. 

For more information, and to follow and comment on the latest energy code developments in the region, on Conduit.