ESCO ESCO Water Conservation and Efficiency 1 — Questions and Answers
Question 1: Which metric is most commonly used by ESCOs to evaluate water efficiency improvements in commercial buildings?
- Gallons per square foot per year (Correct answer)
- BTU per gallon
- Kilowatt-hours per gallon
- Gallons per degree day
Correct answer: Gallons per square foot per year
ESCOs typically benchmark water use intensity in gallons per square foot per year to compare buildings and track savings.
Question 2: What is a cooling tower 'cycles of concentration' (COC) and why does it matter for ESCO water projects?
- The ratio of dissolved solids in blowdown vs. makeup water; higher COC reduces makeup water consumption (Correct answer)
- The number of times the tower fan cycles per hour
- The ratio of condenser water flow to chilled water flow
- The number of annual maintenance cycles required
Correct answer: The ratio of dissolved solids in blowdown vs. makeup water; higher COC reduces makeup water consumption
Increasing COC reduces the volume of makeup water required by the cooling tower, directly lowering water and sewer costs.
Question 3: Which fixture retrofit typically delivers the highest water savings per dollar in a commercial restroom ESCO project?
- Low-flow toilets (1.28 gpf) (Correct answer)
- Waterless urinals
- Sensor faucets
- Low-flow showerheads
Correct answer: Low-flow toilets (1.28 gpf)
Toilets account for the largest share of restroom water use, so replacing high-volume flush toilets with 1.28 gpf models yields the greatest savings.
Question 4: An ESCO is analyzing a hospital laundry room. Which ozone laundry system benefit is most relevant to a water conservation measure?
- Ozone dissolves soils at cold water temperatures, eliminating hot rinse cycles and reducing rinse water volume (Correct answer)
- Ozone increases wash cycle pressure to remove stains faster
- Ozone replaces bleach with a dry chemical additive
- Ozone requires a dedicated water softener loop
Correct answer: Ozone dissolves soils at cold water temperatures, eliminating hot rinse cycles and reducing rinse water volume
Ozone laundering allows cold-water washing and shorter rinse cycles, cutting both water and energy consumption significantly.
Question 5: For ESCO measurement and verification of water savings, which IPMVP option is best when a submetered water meter is installed on the retrofitted system?
- Option B — Retrofit Isolation with continuous measurement (Correct answer)
- Option A — Retrofit Isolation with partial measurement
- Option C — Whole facility metering
- Option D — Calibrated simulation
Correct answer: Option B — Retrofit Isolation with continuous measurement
Option B uses continuous metering of the isolated system to directly measure actual consumption before and after the retrofit.
Question 6: What is the primary purpose of a water audit baseline in an ESCO performance contract?
- To establish pre-retrofit consumption figures against which guaranteed savings will be measured (Correct answer)
- To satisfy EPA stormwater permit requirements
- To qualify the building for a LEED water credit
- To determine the replacement schedule for aging pipes
Correct answer: To establish pre-retrofit consumption figures against which guaranteed savings will be measured
The baseline documents pre-project water use so that post-retrofit savings can be calculated and compared against the guaranteed amount.
ESCO ESCO Water Conservation and Efficiency 1
Which metric is most commonly used by ESCOs to evaluate water efficiency improvements in commercial buildings?