Most facility managers primarily think about energy efficiency as managing electrical use in appliances and devices, but many never realize that water consumption has a direct relationship with energy consumption. Water is a critical resource and is needed in many facilities, from drinking water to flushing toilets. Since water requires some pumping or treatment before it is able to be used, and that all the pumping/treatment requires energy, reducing potable water also reduces energy consumption. There are three major factors in mitigating water consumption and therefore reducing energy usage.
Factor 1: Discovering General Waste
As a facility manager, upgrading water fixtures can help reduce the water consumption. In general, most never realize the incredible amount of water toilets and urinals use every time a person flushes. Depending on the age of bathroom fixtures, they could be using up to 80% more water than newer fixtures. I have seen many buildings in which the toilets use up to 3.5 or even 5 gallons of water per flush (gpf). While some facility managers might think that urinals are more efficient than toilets, think again. While not as bad as toilets, older urinal fixtures could use up to 3 gallons of water. Incredibly, there are now some urinals that use only 1/8 gpf. While I’m not too sure how many times urinals are flushed in a facility, I do know that if a facility replaces old toilets with newer fixtures that use less water, water consumption is reduced and as a result, energy consumption is reduced.
Factor 2: Discovering Issues
Although discovering and replacing wasteful water fixtures will help solve the problem, the replacement will do no good if there are water leaks. Facility managers need to realize the importance of maintaining regular inspections. This is especially true for water fixtures as a leaking toilet isn’t any better than a high gpf toilet. Actually, depending on the problem, leaks or failed valves and pipes are far worse as it could cause catastrophic water damage to the property. Water flow metering isn’t the only piece of the piece of having a proper water management system. Other related equipment that needs to be monitored/maintained include valves, faucets, etc. Having a proper water management can not only help identify water leaks and water flow rates reducing energy consumption, it could also help avert a potential disaster.
Factor 3: Fixing User Behavior
The usage of water efficient fixtures is the same in energy-efficient appliances. If the user of said energy-efficient appliance leaves it on for 24/7, energy usage has been reduced, but not to its fullest potential. However, the main difference is that water consumption is a role that is driven by occupants. Unlike energy efficiency and energy management, it is difficult to “turn” water off without getting major user complaints. This is also compounded that not many occupants are thinking of water unless the area where they live in is going through a water crisis.
The strategy for overcoming user behavior is two-fold: education and testing, in which the latter is easier of the two. Testing can be done in a variety of a ways such as installing new equipment quietly and observing user reaction. Education is the harder part as it covers a wide variety of areas from changing ingrained behaviors to information sharing, such as the informing users about how to properly flush dual-flush toilets. Unlike water consumption efficiency where there is little to no attention, there are many champions promoting and supporting energy efficiency programs. As more people are aware of the growing problem of water overuse, fixing user behavior will also reduce water consumption and as a result, further reduce energy consumption.
Integrate Water Management into BMS
As said previously, water management is an important piece of tool that facility managers are armed to not only protect the building from potential water-related disasters but also in reducing water/energy consumption by identifying leaks and potential areas of improvement. Since facility managers have to juggle with other systems such as HVAC, lighting, security, and other control systems, why not integrate the water management into the same BMS? In this way, the facility manager is armed with the information to improve functionality and reduce consumption. Since predictive/preventive maintenance is a necessary part of the water management system, integrating with the BMS can help operate and maintain an efficient, sustainable building.
Learning the factors that contribute to water consumption, the relationship it plays with energy consumption, along with actively seeking ways to understand the necessary tasks for predictive/preventive building maintenance is a step in the direction of a move towards a much more sustainable and resilient future.
7 years ago
Some figures could be helpful to illustrate the relationship between water consumption and energy.
The supply of 1 cubic meter of drinkable water is requesting an average of 0.5kWh.
Ther same amount of energy is necessary to treat 1 cubic meter of wastewater.
Around 5kWh is requested for desalination of 1 cubic meter of sea water.
Water is free, but clean, drinkable water needs energy and money.
7 years ago
Thank you for commenting. I definitely agree with you that figures it would be nice. However, for this article, I just wanted to make my point across that there are three main facets in reducing water consumption.