Page 138 - The Engineering Guide to LEED-New Construction Sustainable Construction for Engineers

118 Cha pte r T h ree

Daily Uses per Person
Transient: Transient:
Variable FTE ∗ Student/ Retail
Fixture Type Gender Acronym Uses Visitor Customer Resident †
Water closet use Male WCUM 1 0.1 0.1 5
i
Water closet use Female WCUF 3 0.5 0.2 5
i
Urinal use Male UUM 2 0.4 0.1 n/a
i
Urinal use Female UUF 0 0 0 n/a
i
∗ The students as listed in TOW represent transient students, such as those attending a college where they may
take only a handful of classes in one building on certain days. Students in primary schools and other schools
where they remain in the same building every “work” day for the entire school day are actually similar to
full-time employees and should be treated as such. This should therefore be noted in the calculations and the
submittals.
† These resident daily usage rates represent residents who on average also spend part of their days elsewhere,
such as at school or work. It is recommended by the author that for residential facilities where there are
usually 24-h occupancies, such as nursing homes, the resident rates for water closets be, at a minimum, 8,
which is a sum of 3 (for FTE) and 5 (for residences). This should be noted in the calculations and the
submittals.
TABLE 3.2.1 Default Typical Daily Blackwater Fixture Use by Gender

Gallons Generated per Use
[Gallons per Flush (gpf)]
Specific Fixture Type (WCR or UR)
i i
Baseline (conventional) water 1.6 (Blowout fixtures 3.5)
closet
HET foam flush 0.05
HET single flush water closet 1.28 gravity
1.0 pressure assist
HET dual flush water closet 1.6 full flush
1.1 low flush
1.27 average ∗
Composting toilet 0
Baseline (conventional) urinal 1.0
HEU urinal 0.5
Nonwater urinal 0
∗ This average is as calculated for one-third usage with full flush.

TABLE 3.2.2 Typical Blackwater Generation by Fixture Type as Given in
LEED 2009