The Water Audit portion of the Federal Energy and Water Audit Report may be used to collect data to reflect a building’s water usage and recommendations for improvement. Input data fields for Plumbing Fixtures and the guidance listed here were derived from Section 3.3 of the Water Evaluation Tools Handbook.
Plumbing fixtures are commonly present in restrooms, locker rooms, and kitchenettes. Fixtures include toilets, urinals, faucets, and showerheads. The following information describes the data collected for plumbing fixtures and general information and tips for gathering the information.
Collect the following general information for spaces containing plumbing fixtures.
- Restroom Type (for Toilets) – Pull down menu selections: Male, Female, Unisex
- Plumbing Area Type (for Faucets) -- Pull down menu selections: Bathroom, Kitchen
Data Collection for Plumbing Fixtures
Toilets and Urinals
There are two primary types of toilets, tank and flush valve. Tank toilets operate in one of two ways: gravity or pressure assisted. Gravity tank toilets send water via gravity from the tank into the bowl by releasing a flapper valve between the tank and the bowl. Pressure-assisted tank toilets contain a vessel inside the tank filled with pressurized air. When the toilet is flushed, the pressurized air pushes the water into the bowl at a high velocity to create the flush.
Flush valve toilets and urinals send pressurized water directly from the supply line through a valve and into the bowl to create the flush. There are also two types of flush valves. Diaphragm flush valves have a rubber gasket, or diaphragm, that separates the upper and lower chambers in the valve housing. When the toilet is flushed, the diaphragm gasket flexes, moving water through the valve and into the bowl. In a piston flush valve, the valve houses a piston that separates the upper and lower chambers in the valve housing. This valve housing has a smaller diameter than the diaphragm valve. When the toilet is flushed, the piston lifts, allowing water to flow from the inlet pipe under the piston and into the bowl.
Non-water urinals (see Figure 9) have no flushing mechanism and use no water to flush waste down the drain line. The fixtures use a cartridge containing liquid that prevents odors from permeating the restroom. When using the building-by-building method to determine an average flush rate, including non-water urinals for determining average flush rate in a building is at the user’s discretion, considering the presence of non-water urinals in both assessed facilities and the overall campus.
- Toilet Type -- Pull down menu selections: Tank, Flush Valve.
- Flush Mount Type – Available if Toilet Type = Flush Valve; Pull down menu selections: Floor Mount, Wall Mount, Rear Discharge. Floor-mounted with rear discharge is bolted to the floor and the wall, with the discharge outlet facing toward the wall. The type of fixture mounting is important because future replacement fixtures should discharge to the same locations as existing fixtures.
- Primary Flush Valve Type – Available if Toilet Type = Flush Valve; Pull down menu selections: Diaphragm, Piston, Non-Water
- Average Flush Time (in seconds) – Available if Toilet Type = Flush Valve. The actual flush time of a flush valve toilet and urinal is estimated by counting the number of seconds from the time the lever is actuated until the valve closes.
- Automatic Flush Sensor – Yes/No
- Rated Flush Volume – For Tanks, this is generally given in gallons per flush stamped either on the china near the bowl or inside the tank itself. For Flush Valve toilet or urinal, this is typically found stamped either on the china near the bowl or on the flush mechanism just under the lever.
- Total Number of Toilets
- Urinal Type -- Pull down menu selections: Standard, Floor Trough.
- Valve Type – Pull down menu selections: Exposed, Concealed.
- Automatic Flush Sensor – Yes/No
- Discharge Tube Diameter – The discharge tube is the pipe (¾″ or 1¼″ diameter) that connects the flush valve to the fixture. A thin pipe denotes a ¾″ diameter tube.
- Rated Flush Volume – For Flush Valve toilet or urinal, this is typically found stamped either on the china near the bowl or on the flush mechanism just under the lever.
- Average Flush Time (in seconds) – The actual flush time of a flush valve toilet and urinal is estimated by counting the number of seconds from the time the lever is actuated until the valve closes.
- Total Number of Urinals
Most buildings have public faucets and/or private faucets. Public faucets are intended to be used in high-traffic public areas and are generally found in restrooms. Collect the following information for faucets.
- Automatic Sensor – Identify if the faucet is operated with a sensor (Yes), or is operated manually (No). Sensor faucets operate by sensing when an object is in front of the faucet and opening a valve to allow water to flow. Manual faucets may have either two handles, one each for hot and cold water, or a single handle that mixes hot and cold water before it exits the faucet.
- Has Aerator – Identify if the primary fixture type is operated with an aerator (Yes), and whether the aerator is working or not (Yes/No, or N/A if unknown). The vast majority of faucets either have an aerator attached or have threads to which an aerator can be attached, which controls the flow of water coming out of the fixture. In rare instances, faucets may have no aerator and no threads. Typically, these are old faucets that require whole-fixture replacement.
- Rated Flow Volume -- This value is stamped on the faucet (see Figure 16) where water exits into the basin and is generally provided in gpm.
- Actual Flow Volume – The faucet flow rate may be measured by using a metered flow bag by turning the faucet on to the maximum flow and capturing the flow for 5 seconds (using a stopwatch). Then hold the bag top with two hands and read the gpm according to the graduated lines on the metered flow bag. Note that if there are hot and cold handles, both should be open.
- Total Number of Faucets
Three of the most often used general categories of showerheads are threaded fixed, handheld, wall mounted.
Threaded showerheads are the most common type. These heads can be removed or replaced by simply unscrewing the existing showerhead and attaching a new one.
Wall-mounted showerheads are mounted either directly to the wall or are included in a box that also contains the water controls. These showerheads cannot be unscrewed from the pipe coming from the wall; instead the whole fixture must be replaced where it attaches to the plumbing distribution system. These types of showerheads are typically more expensive to retrofit than threaded style showerheads but are less common.
Collect the following information for showerheads.
- Showerhead Type -- Pull down menu selections: Hand Held, Threaded Mixed, Wall Mount
- Rated Flow Volume -- Typically provided in gpm and often marked in the center or around the outside of the showerhead.
- Actual Flow Volume -- Using the same technique as faucets, showerhead flow rate may be measured using a metered flow bag by turning the showerhead on to maximum flow and capturing the flow for 5 seconds. Hold the top of the bag with two hands and read the gpm. Note that if there are separate hot and cold handles, open both.
- Total Number of Showerheads
- Percentage of occupants showering daily Weekdays and Weekends -- In order to estimate water used by showering, it is critical to determine how frequently the showers are used. Interview the building manager and/or occupants to get a sense for how often occupants shower. In cases where there is uncertainty, request a best estimate.