Water and Energy are paired together inextricably, since it requires high volumes of water to develop energy and a lot of energy is used for distributing water and circulating it in buildings and municipalities. Conserving water extends beyond restroom fixtures, and significant water reduction is possible without high expense.
Commercial buildings consume large amounts of water; more than 47 billion gallons per day. Commercial building water usage usage is rarely measured inside of a building since the meter is at the street, and sewer use theoretically equals the volume that enters the building.
Submetering in buildings tells a different story and will help to conserve substantial water and sewer costs when monitored. Sewer fees are usually higher per 1,000 gallons than fresh water, and many people overlook that they have two rates on their water bill.
Reducing fresh or sewer water charges are important for controlling operating expenses in the near term, so that as water prices steadily climb 3-5% per year, building owners and operators can reduce their future monthly costs by developing and implementing water saving strategies. Most companies have formal energy conservation programs, yet many organizations have no long-term plans for reducing the water that they consume.
Commercial buildings have abundant opportunities to reduce water use that saves operating budgets in the near-term, while better positioning for the future.
Smart meters, digital sensors, and data analytics offer valuable awareness on where water savings can be captured. As municipalities and companies develop increasingly detailed climate change plans, water plays a significant role.
Here are 10 ways that building owners and operators can conserve water with minimal expense.1. Perform a Commercial Building Water Audit
Water audits range in complexity but they basically evaluate a building’s existing water use by functional area. It’s a good idea to include an energy audit as well. A basic water audit may require only a few hours while an intensive evaluation of a building‘s water and mechanical systems may take a couple of days to complete at larger facilities. A qualified professional will assess plumbing systems, fixtures, cooling system, hot water system, irrigation and other components of a facility. Water and energy bills will be reviewed, along with historic system repair bills to develop an understanding of the building’s operations.
Some municipalities provide water audits at no charge, since the identified outcomes that are implemented save costs long-term for the community.2. Submeter Cooling Towers
Evaporative cooling systems consume 20-50% of a building’s water, and they evaporate approximately 70% of the circulating water to remove heat from the building. The evaporated water doesn’t enter the sewer, yet without a submeter the building will be charged for all of it. Most cities offer evaporation credits that are applied to the next month’s bill, which saves hundreds or often thousands of dollars per month, and the programs require a make-up and blowdown meter.
Submetering cooling towers has numerous benefits, including identifying leaks or overflows. With digital monitoring and analytics, additional water and energy savings are captured by identifying ways for improving operating efficiencies. Smart meters, IoT sensors and analytics provide tremendous value.
Obtain a baseline of 12+ months of water use for benchmarking in the future.
3. Submeter Irrigation
Smart meters for irrigation provide good insights on water being used at various stations, with granular monitoring of specific areas. Water for the landscape does not enter the sewer, so a rebate should be available, based on sub-metered data. Irrigation credits can be submitted to the city for credit on water bills, which will reduce water costs significantly.
Soil moisture sensors provide real-time data that prevents over-watering, and several irrigation management systems use data feeds from local weather stations to reduce unnecessary water use when it is raining.
With data analysis and planning, most properties can maintain a healthy landscape while reducing irrigation water use by 40-70%. Many properties will conserve millions of gallons of water and tens of thousands of dollars per year. Building operators will increase net operating income (NOI), decrease operating expenses, and conserve water by monitoring and adjusting irrigation allocations. The ROI of implementing smart irrigation is usually within 12 months and can be as short as 90 days.
4. Upgrade to Water Efficient Fixtures
Most buildings have made the switch to 1.28 gallons per flush toilets, and it’s noticeable these days when a flush uses more water than that. Some older models flush with up to 5 gallons, so changing out fixtures adds significant water savings for commercial building operators. Cost savings occur on the day of the switch-out to efficient toilets, and applies to urinals, faucets and aerators.
EPA WaterSense labeled bathroom sink faucets use a maximum of 1.5 gallons per minute, which is nearly half of the flow of prior faucets. Additionally, faucets with electronic sensors stop the flow when the water is not needed.
Aerators conserve about 30% of water without reducing the effective use of the flow. Some combinations of faucets and aerators can have such low flow that it’s frustrating to use, but properly balanced components conserve water and cost without diminishing the user’s experience.
Improving restroom fixture efficiencies will pay out in a short period of time depending on municipal rebates, local water costs and capital structure.
5. Reduce Pressure on Water lines
Many buildings require booster pumps to improve water pressure on upper floors. This often results in the pressure on lower floors being higher than necessary, exceeding the specified capacities of fixtures. This not only wastes water but runs the risk of rupturing piping and damaging fixtures. Water pressure regulator valves are important, though the root cause of over-pressurized water lines should be remedied.
We have observed that limescale forms more readily in areas where high and lower pressure meet, since scale forms during pressure and temperature change. High pressures increase scale formation in bends and pipe diameter reductions, and where fixtures impede flow.
Consider installing a series of variable speed pumps that balance water pressure while reducing the energy used to maintain sufficient flow. This applies to circulating hot water systems as well, since less energy is needed when reduced water is being circulated. Cost savings of energy and repairs are realized in a short period of time.
6. Smart Meters and Sensors
Water use varies throughout a building depending on purpose, schedules and season. Internet of Things (IoT) enabled sensors and meters have improved monitoring significantly in recent years. When processes are measured, improved efficiencies are more easily achieved.
Historically, municipalities collected water meter readings once per month manually. By the time a water bill arrived, a leak or abnormal use would be weeks or a month from when it occurred. No trending was available to determine patterns or exceptions in water use, with no way to identify where or when an abnormality occurred.
Real-time monitoring of discrete segments in a building improves understanding of water use, including irrigation, cooling towers, boilers, pools, water features, departments and other uses that occur on a schedule, like restaurants or showering areas.
Automated analysis provided by machine learning (or artificial intelligence) detects and interprets abnormal water use and will send a text or email alerts immediately so a building manager is aware of conditions that can be addressed.
Historic water data is not maintained for most buildings, so benchmarking cannot occur. Data collected over time provides abundant points of reference for trending to automatically develop and be analyzed. This works beyond a single building, as multiple buildings in a portfolio can be analyzed in real-time as well, so efficiencies can be identified continuously with benchmarking across the portfolio.
Smart water management systems also calculate actual water cost savings per segment or group of buildings so water conservation and cost savings are measured and consistently managed. Evaporation and irrigation credits are calculated and presented in monthly reports.
Graphical presentation of data and trends provide simple, data-rich insights on key aspects of water systems that users can review in moments and take action promptly when anomalies appear. Smart Water provides cost savings along with water and energy conservation.
ROI for smart meters and sensors is realized often in months due to corrected inefficiencies, repair notices and trending analysis that reduce operating expenses in the short term.7. Condensate Recovery System
Commercial HVAC systems produce considerable volumes of condensed water that collects on piping. Condensate water is distilled and free of calcium and minerals, so it is ideal to use in evaporative cooling towers. Most facilities collect the condenser water and discard it into the sewer but increasing numbers of facilities are diverting the water into reuse. The volume of water produced can be significant in hot southern climates, often exceeding 15-20 gallons per minute.
Not only does reusing condenser water reduce water costs, but the low mineral content improves the conductivity of circulating water in cooling systems, which extends the use of the water before discharging to the sewer. Less frequent blowdown saves both sewer and fresh water costs.
We suggest that a digital meter be installed on condenser water collection lines so the contribution is monitored. Depending on the size of the equipment and daily load, the captured condenser water can save several million gallons of water per year.
8. Evaluate Landscapes to Reduce Water Consumption
Buildings without green spaces and landscaping have diminished value for tenants and investors, and although xeriscaping implies desert plants to many people, there are numerous benefits of native plants. However, large areas of turf and tropical plants use considerable water, and abundant alternatives are available. Turf grass requires frequent mowing, water, and chemicals to appear well maintained. Cost savings from labor and energy could be enough to consider alternatives, with water savings adding to cost savings that will increase net operating income (NOI) in a short period of time.
Planting hardy native or adapted species of plants can provide similar color and variegation to a building’s exterior while saving water and cost of seasonal change-outs. Water use can be better managed with perennial plants, which live for many years. Many species require minimal maintenance and care, while being drought tolerant.
Fountains and water features can consume high volumes of water due to evaporation. In areas with hard water, the removal of accumulated scale requires frequent draining of ponds and fountains and requires considerable labor and chemicals. A physical water conditioner will prevent scale and biofilm formation, resulting in less maintenance without chemicals.
Consider reducing the amount of water being sprayed into the air, which will involve replacing nozzles. Winterizing fountains and ponds during cold weather reduces maintenance and eliminates water requirements for a portion of the year.
9. Install a Rainwater Harvesting System
Applying drinking-quality water for watering lawns and landscapes is remarkably wasteful yet continues to be a standard practice. A viable alternative is to supplement or replace the fresh water source with a rainwater catchment system. Evaluating the watering demands of a commercial landscape will provide quantities and frequency inputs for calculating the appropriate tank size. This is a good time to evaluate the varieties of plants for drought resistance in the landscape and adjust as appropriate.
The cost of a large tank, as well as locating it on a property is a challenge for some properties, in addition to costs associated with pumping equipment. The cost-benefits of a rainwater catchment system depends on site specific conditions, and the elements of a High Performance Building design strategy that includes LEED or other program credits.
As local water resources are stretched to accommodate population growth and economic development, new water supply strategies will be necessary to meet growing demand. Rainwater harvesting is an abundant resource in most regions that can become a part of a sustainable water supply strategy for local communities, while reducing long-term water demand for commercial properties.
10. Physical Water Conditioning
Physical water conditioning differs from chemical treatment, as no chemicals are used to physically improve the water. Dissolved minerals in municipal or well water naturally precipitate where temperature or pressure change occurs, such as water heaters, cooling towers, spray heads and other areas of water systems that force calcium and other minerals to super saturate. When dissolved calcium concentrates the result is often limescale.
Physical water conditioners use a frequency that travels through the water and causes calcium and mineral ions to bond. The continuous bonding causes dissolved calcium to precipitate into microscopic particles that cannot accumulate as scale on surfaces.
Physical water conditioners replace salt-based water softeners, and prevent scale formation on boilers since the particles of calcite cannot attach, and pass through the plumbing and into drains. The prevention of scale on piping and equipment improves heat transfer so boilers and cooling towers operate at optimal efficiency.
Cooling towers require less energy and chemicals, and the prevention of scale formation allows significantly higher conductivity (4,000 µS vs. 1,800 µS) without concern for scale or fouling. Water that was blown down at 3 cycles of concentration can be used up to 9 cycles, which saves sewer and fresh water costs. Digital sensors and meters validate the performance in real-time.
Due to the reduced chemical requirements, and considering a switch to eco-friendly water chemistry, the water that is discharged from a cooling tower can be repurposed to be used for irrigation, which replaces the use of drinking quality water on landscaping. Further, when cooling tower water is discharged into the sewer, the lower levels of biocides have less impact on the wastewater treatment plants which use live bacteria to process effluent.
ROI from physical water conditioning generally range from 6-18 months.
Water Conservation in the Digital Age
Digital technologies have become central to operating facilities, and operators expect to view graphic presentation of their operating data securely on a phone. Data analytics and machine learning provide increasingly granular insights on water system management; just as they do for energy efficiency.
It is time to place greater focus on water conservation, and to incorporate best practices for reducing the water footprint of commercial buildings and campuses. Water prices will continue to rise, unlike energy prices that fluctuate. Planning ahead for water conservation requires a set of metrics and a baseline of historic operating data.
Organizations like the US Green Building Council (USGBC), Dallas 2030 District and other 2030 Districts support actions to help building operators conserve 50% of water use and provide tools and best practices that help them make improvements. Water conservation is about metrics and data that support and guide performance.
Intentional Water Conservation
Consider how your organization can save 10% of annual water use. Then think about 30% conservation. It begins with a thoughtful evaluation, and numerous adjustments that are carefully measured, with data available to your stakeholders. Once savings are captured, the process improvements endure.