One of the major features in cove.tool's growing capabilities library is the Indoor Water Use Tool. This feature allows users to calculate their building design's Interior WUI (Water Use Intensity), Irrigation/Outdoor Water Use, Stormwater Management, Cooling Tower Water Use, and water-related LEED Points. The design of processed water systems is important to know because buildings' potable water usage constitutes a large portion of the world's fresh water consumption, and can be a sizable hit on operation costs if your fixture value is meeting efficiency targets.
INDOOR WATER USE
What is Indoor Water Use?
Indoor Water Use is the amount of water [expressed in gallons] that will be required for a typical year of operation. Also expressed as WUI, or Water Use Intensity (gal/ft²/yr), this calculation is done by using flow rate values of 5 standard indoor water fixtures and occupation density of your building to determine your water usage needs. Assumptions for this calculation follow the LEED’s Indoor Water Use calculation method (LEED v4.0 - WE p2), default gender ratio (50:50), and baseline fixture values (LEED v4.0 - WE p2, Table 1: Baseline water consumption of fixture and fittings). Strategies to reduce potable water use in buildings entail the selection of efficient plumbing fittings, fixtures, and equipment. Building using cove.tool's water use page can test high-efficient fixtures by testing optimal fixture flow rates.
How to use the Indoor Water Tab?
Locate the flow rates for the 5 Fixture Categories and input them into the manual input box. To find a fixtures flow rate, users can locate these values in any of the following options:
- Plumbing Fixture Schedule - locate a drawing set of a similarly sized/equipped project to determine applicable flow rates.
- WaterSense Label - search for high-efficiency products on the WaterSense Website. Each eligible fixture will list it's flow rate.
- Fixture Cutsheets - Manufacturers will list fixture data for all fixtures and appliances. Search manufactures near you for values
Determining Indoor Water Usage
Cove.tool uses user-defined Occupation Density, Schedules, and LEED v4 Reference Guide data to determine the water use calculations. See below to learn more about each water use assumptions.
- Number of fixtures: Determined by Occupation Density
- Days of Operation: User-defined Schedules
- Duration of Use and Uses per Day: Taken from "LEED v4.0 - WE p2, Table 8 &9: Nonresidential and Residential default fixture uses"
- Baseline Fixture flow rate: Taken from "LEED v4.0 - WE p2, Table 1: Baseline water consumption of fixture and fittings"
- Flow Rates: User-defined values
More on Indoor Water Use here.
What is Irrigation?
Also known as outdoor water use, refers to the amount of water used to irrigate outdoor vegetation. Landscape irrigation practices consume large quantities of potable water, sometimes accounting for 30% to 70% of the water consumed in non-agricultural use. More on irrigation water use here.
What is Cooling Tower Water Use?
A cooling tower is a heat rejection device in HVAC, which removes unwanted heat from a water-cooled chiller. This is done by bringing air and water into direct contact with each other to reduce the water’s temperature thereby cooling water streams. The cooled water is then returned to the building's chiller to continue the cycle to cool and dehumidify the indoor air. More on cooling tower water use here.
What is Stormwater Management?
Also known as rainwater use or runoff management, is derived using local rainfall data, the run-off coefficient for each surface on site, the total area of each surface type, and the amount of onsite stormwater storage. More on stormwater management here.