The Future of Hot Water Management Has Arrived

In Hawaii, which has the highest costs in the nation for electricity and natural gas, the ability to effectively manage operational costs is critical in maintaining an AOAO’s financial stability. There are many energy-efficient methods to achieve lower costs and improve operational efficiency, such as LED lighting, solar PV, HVAC upgrades and solar hot water.

But little focus has been given to energy efficiencies within the hot water environment.

Typically, a building will set the aquastat (target set point), at a desired temperature and the heat source will chase that temperature until it is satisfied, regardless of building demand. This is inefficient, because every building has its own unique supply and demand curve, and those loads vary by day of the week as well as the makeup of the tenants.

In Hawaii, there are typically two demand periods: When people are getting ready for work, and when people come home at the end of the day, do laundry, wash dishes and other household chores.

During these peak periods the facility must have enough hot water available to meet these demands. Conversely, during the off-peak periods there is an opportunity for energy savings provided it is managed properly and there is enough lead time prior to peak needs.

With proper monitoring of your hot water environment, operational visibility can be achieved as to how and why your facility is performing the way it is, where your facility is strong and where it is weak. Once realized, a strategic plan can be designed that when implemented, will provide cash flow positive savings without any adverse impact to your water delivery temperatures and your residents.

The benefits are not only reduced utility expenditures, but improved and documented operational temperatures and costs. And there is the added benefit of a direct reduction in your system maintenance costs—if the system runs less, it requires less maintenance and will have a longer useful life.

Hot water in Hawaii is different, but why?

The cost of living is higher in the Islands than other places in the country, and that includes the utility rates. When a high utility bill comes in, it is often taken for granted because it is Hawaii and we are used to these costs.

Another factor is that many of our buildings are 30 to 40 years old—some with adequate reserves, others without. Over this span of time many changes have occurred in the buildings because of leaks and repairs, equipment changes and upgrades, emergencies or implementation of solar, and with each of these changes comes a performance as well as economic impact to the building’s hot water system.

Because some of these changes were not always planned and some were emergency repairs, it is not always the case that the best or most efficient solution was implemented. This creates some interesting and unique scenarios.

Monitoring: A Case Study

Building A was originally plumbed for gas and converted to heat pumps years ago. Hot water is not an issue as everyone has ample hot water and there were rarely complaints. For as long as anyone can remember, the average monthly expenditure for hot water ranged between $4,800 and $5,400. With effective hot water monitoring in place, each component of the facilities hot water system could now be analyzed for performance, effectiveness and economics.

The findings: The small backup heat pumps were running as the primary source and bypassing the more efficient main heat pump. With cost and operational data, an operating change was made to shift the load, requiring the main heat pump to do most of the work, with the backups acting as backups. The result was an immediate cost reduction of 50 percent, and a more consistent temperature delivery.

Now, with effective monitoring, control and analysis in place, the property knows exactly how their system is operating and if a deviation occurs it can be promptly addressed. These savings, $2,500 per month can now be used for other projects or to strengthen the reserve fund.

A Powerful Tool

In Hawaii, most hot water systems are master metered, which means such common area items as lighting, gas stoves, BBQs, Tiki torches, laundry areas and elevators contribute to the facility’s overall consumption. As a result, it is difficult to isolate the expenditures directly related to hot water generation. And, until now, tt also has been difficult to develop a methodology that is flexible enough to handle the myriad hot water environments in Hawaii,

Property managers should reach out to a company that has developed a cost-effective hot water monitoring and control system that gathers detailed operational information on the hot water system and accurately calculates the amount of gas or electricity being used to generate hot water. The capability allows you to break out hot water generation costs and provides a more detailed understanding of the building’s economics in more detail.

Another benefit of a hot water monitoring and control system is the ability to evaluate and validate service and repair work that is performed on your hot water system. If you can determine costs for hot water before the repairs or maintenance is performed and determine costs after the work is performed, you can now calculate a return on investment for the work performed.

This can be an extremely valuable tool when working with a building’s executive board. The ability to validate the cost of work performed can be a powerful tool to assist AOAO boards in making the right decision to maintain and repair equipment.

Through effective analysis, your AOAO board and maintenance teams can now plan and act upon actual facts that exist in your environment, and implement technologies and methodologies that will result in operational improvement.

Hot water monitoring and control should be a part of every building’s operational and energy-saving goals. Until now it has been a hidden part of building operations and difficult to manage—but it does not have to be.

Dave Felice has been in energy efficiency here in Hawaii for over 9 years. He is the head of sales for GreenBox Energy Hawaii. GreenBox Energy is an industry leader in hot water monitoring and control systems. Dave can be reached at 808-295-8446 or