WA Energy Code Questions - Mechanical.pdfWinCo - Edmonds, WA
Washington Energy Code Questions
1/30/2015
1. C403.2.4.10 Direct digital control system capabilities — 2. Demand Response Setpoint Adjustment:
Control logic shall increase the cooling zone set points by at least 2 F and reduce the heating zone set
points by at least 2F when activated by a demand response signal. Then demand response signal shall
be a binary input to the control system or other interface approved by the serving electric utility.
As discussed in our meeting, this will not be a requirement for the project.
2. C403.2.5.4.1 Kitchen Hoods. Each kitchen area with total exhaust capacity larger than 2000 cfm
shall be provided with make-up air sized so that at least 50% of exhaust air volume be (a) unheated or
heated to no more than 60F and (b) uncooled or cooled without use of mechanical cooling.
As discussed in our meeting a Captive Air hood system with a heated supply air stream will meet
the intent of the code. The building management system will limit heated air temperature to
60F.
3. C403.2.6.1 Energy Recovery ventilation systems. Any system with minimum outside air
requirements at design conditions greater than 5000 cfm or any system required by Table C403.2.6
shall include an energy recovery system. The energy recovery system shall have the capability to
provide a change in the enthalpy of the outdoor air supply of not less than 50% of the difference
between the outdoor air and return air enthalpies, at design conditions. Where an air economizer is
required, the energy recovery system shall include a bypass or controls which permit operation of the
economizer as required by Section C403.4. Where a single room or space is supplied by multiple units,
the aggregate ventilation (cfm) of those units shall be used in applying this requirement.
Exception: An energy recovery ventilation system shall not be required in any of the following
conditions: 6. Cooling energy recovery in Climate Zones 3C, 4C, 513, 5C, 613, 7 and 8.
Would it be acceptable to not include an energy recovery ventilation system on this project? A
majority of the ventilation air is exhausted through department exhaust fans, so there is very
little left over to exhaust through an ERV (approximately 4400 cfm). In order to maintain
positive pressurization in the building and attempt to reduce infiltration through the front doors,
we would prefer to over -pressurize the building by the 4400 cfm.
4. C403.3.1 Economizers. Each cooling system that has a fan shall include an air economizer meeting
the requirements of Sections C403.3.1.1 through C403.3.1.1.4.
Exceptions: 2. Systems with dehumidification that affect other systems so as to increase the overall
building energy consumption. New humidification equipment shall comply with Section C403.2.3.4
Supermarkets do not typically utilize air economizers in the sales area, due to the effect of
humidity on open refrigerated cases. Also, the sales area air handler pulls cold return air off of
the floor, beneath the cases, which lowers the mixed air temperature and reduces the cooling
load. An economizer would eliminate this energy saving concept by bringing outside air into the
store instead. Would it be acceptable to not include an air economizer for the sales area air
handler?
5. C405.2.5 Area controls. The maximum lighting power that may be controlled from a single switch
or automatic control shall not exceed that which is provided by a 20 ampere circuit loaded to not
more than 80 percent. A master control may be installed provided the individual switches retain their
capability to function independently. Circuit breakers may not be used as the sole means of
switching.
Pertaining to Energy Code section C405.2.5, would it be acceptable to have the BMS system
control the Main Sales floor lights through Contactors, rather than individual switches as the
code requires? We would like to have a zoned approach to the Main Sales Floor, where the entire
Main Sales floor is controlled by Daylighting. The Store is 24/7 and only closed for 2 days a year,
and when the store is open, it is entirely open, not just a portion. We expect there to be 20
circuits to power lighting in the Main Sales floor. Individual control of each circuit would be
confusing and unused as the lights would be on at all times except when daylighting dictated
otherwise. The Contactors would be controlled by the BMS system which can be accessed by the
internet throughout the store, and will have daylighting and Holiday programming for automatic
dimming and shutdown as needed.
6. Daylight zone control. Daylight zones shall be designed such that lights in the daylight zone are
controlled independently of general area lighting and are controlled in accordance with Section
C405.2.2.3.2. Each daylight control zone shall not exceed 2500 square feet.
Pertaining to Energy Code section C405.2.2.3, would it be acceptable to treat the Main Sales
floor as one Daylighting Zone, as opposed to broken up into the 24 zones with a maximum area
of 2500 sq. ft. the code requires? As the Main Sales floor is one continuous open space, the
overall lighting levels through the Main Sales floor will be similar. The code also requires a three
minute delay on control, so passing clouds will not require the lights to be dimmed. We have
multiple light sensors throughout the Main Sales Floor that are averaged to control the
Daylighting zones. There are additionally rows of lights that are not covered by the Daylighting
Zones area that we still intend to control due to the known performance of the skylights
themselves.