Washington Administrative Code › Title 51 - Enterprise Services, Department of (Building Code Council) › Chapter 51-11C - State Building Code adoption and amendment of the 2021 edition of the International Energy Conservation Code, Commercial › Section 51-11C-41200 - Section C412-Compressed air systems

Current through Register Vol. 24-14, July 15, 2024
C412.1
General.
All new
compressed air systems
, and all
			 additions or alterations of
compressed air systems
where the
			 total combined horsepower (hp) of the compressor(s) is 25 hp or more, shall
			 meet the requirements of this section. These requirements apply to the
			 compressors, related piping systems, and related controls that provide
			 compressed air and do not apply to any equipment or controls that use or
			 process the compressed air.
EXCEPTION:
Medical gas compressed air systems in health care
						  facilities.
C412.2
Trim compressor and storage.
The compressed air system shall be
			 equipped with an appropriately sized trim compressor and primary storage to
			 provide acceptable performance across the range of the system and to avoid
			 control gaps. The compressed air system shall comply with 1 or 2 below:
1. The
compressed air system
shall include one or more variable speed drive (VSD) compressors. For systems
			 with more than one compressor, the total combined capacity of the VSD
			 compressor(s) acting as trim compressors must be at least 1.25 times the
largest net capacity increment
between combinations of
			 compressors. The
compressed air system
s hall include
primary storage
of at least one gallon per actual cubic feet
			 per minute (acfm) of the largest trim compressor; or
2. The
compressed air system
shall include a compressor or set of compressors with total effective trim
			 capacity at least the size of the
largest net capacity
			 increment
between combinations of compressors, or the size of the
			 smallest compressor, whichever is larger. The total effective trim capacity of
			 single compressor systems shall cover at least the range from 70 percent to 100
			 percent of rated capacity. The effective trim capacity of a compressor is the
			 size of the continuous operational range where the specific power of the
			 compressor (kW/100 acfm) is within 15 percent of the specific power at its most
			 efficient operating point. The total effective trim capacity of the system is
			 the sum of the effective trim capacity of the trim compressors. The system
			 shall include
primary storage
of at least 2 gallons per acfm
			 of the largest trim compressor.
EXCEPTIONS:
1. Alterations where the total combined added or
						  replaced compressor horsepower is less than the average per-compressor
						  horsepower of all compressors in the system.
2. Alterations where all added or replaced compressors
						  are variable speed drive (VSD) compressors and
compressed air
						  systems
includes
primary storage
of at least one
						  gallon per acfm of the largest trim compressor.
3.
Compressed air systems
that have
						  been pre
approved
as having demonstrated that the system serves
						  loads for which typical air demand fluctuates less than 10 percent.
4. Alterations of existing
compressed air
						  systems
that include one or more centrifugal compressors.