Page 20 - GRIHA Manual Volume IV - Introduction to National Rating System
P. 20
Building planning and construction 11
Pressure reducing devices
Pressure reducing devices are options to be considered when water line pressure is higher than
50–60 psi. Lowering excessively high-line pressure helps reduce the formation of leaks and also
reduces water flows from spigots, hoses, faucets, and water feed lines. A pressure reduction of 15 psi
from 80–65 psi will reduce water flow by about 10% without sacrificing the water service.
GRIHA speciic information
Objective
To reduce water consumption in the building by using efficient fixtures.
11.1 Commitment
11.1.1 Reduce the total water consumption in the building (by 25% or more) by using low-
flow fixtures.
11.2 Compliance
The following documents are to be submitted.
11.2.1 Narrative demonstrating water-saving measures adopted
11.2.2 Specification sheets from manufacturers for each fixture, indicating the flow rates (at
design pressure of 80 psi for faucets)
11.2.3 Bill of quantities from the plumbing tender indicating the number and flow rates of
various fixtures
11.2.4 Provide design basis calculations demonstrating the reduction in the building’s water
demand as 25% or more
11.3 Appraisal (maximum points – 2)
11.3.1 Reduction in water consumption by 25%. (1 point).
11.3.2 Water-use reduction by 50%. (additional 1 point).
Methodology
Step 1 Once the type and number of fixtures and faucets have been decided as per NBC standards
based on building typology, select the fixtures and faucets of low-flow rates (based on
technology options available in the market).
Step 2 Get the flow rates from manufacturers at standard 80 psi for all faucets and fixtures.
Step 3 Do the iterations on the possible water savings by filling in the calculation sheet available
on the GRIHA website. Select the must suitable fixtures based on possible water savings,
cost constraints, and so on.
Note Here, water consumed in the cooling towers (in case of water-based HVAC systems) is not accounted for.
Guide to use GRIHA online evaluation tool
Depending on the points attempted in a project, click on the relevant box in the goals section.
Given below is a snapshot of the GRIHA Criterion 11 template for a project where both points are
being attempted.
Pressure reducing devices
Pressure reducing devices are options to be considered when water line pressure is higher than
50–60 psi. Lowering excessively high-line pressure helps reduce the formation of leaks and also
reduces water flows from spigots, hoses, faucets, and water feed lines. A pressure reduction of 15 psi
from 80–65 psi will reduce water flow by about 10% without sacrificing the water service.
GRIHA speciic information
Objective
To reduce water consumption in the building by using efficient fixtures.
11.1 Commitment
11.1.1 Reduce the total water consumption in the building (by 25% or more) by using low-
flow fixtures.
11.2 Compliance
The following documents are to be submitted.
11.2.1 Narrative demonstrating water-saving measures adopted
11.2.2 Specification sheets from manufacturers for each fixture, indicating the flow rates (at
design pressure of 80 psi for faucets)
11.2.3 Bill of quantities from the plumbing tender indicating the number and flow rates of
various fixtures
11.2.4 Provide design basis calculations demonstrating the reduction in the building’s water
demand as 25% or more
11.3 Appraisal (maximum points – 2)
11.3.1 Reduction in water consumption by 25%. (1 point).
11.3.2 Water-use reduction by 50%. (additional 1 point).
Methodology
Step 1 Once the type and number of fixtures and faucets have been decided as per NBC standards
based on building typology, select the fixtures and faucets of low-flow rates (based on
technology options available in the market).
Step 2 Get the flow rates from manufacturers at standard 80 psi for all faucets and fixtures.
Step 3 Do the iterations on the possible water savings by filling in the calculation sheet available
on the GRIHA website. Select the must suitable fixtures based on possible water savings,
cost constraints, and so on.
Note Here, water consumed in the cooling towers (in case of water-based HVAC systems) is not accounted for.
Guide to use GRIHA online evaluation tool
Depending on the points attempted in a project, click on the relevant box in the goals section.
Given below is a snapshot of the GRIHA Criterion 11 template for a project where both points are
being attempted.
