New Years Resolution: Preventative Maintenance of HVAC System Servicing Data Centers

Data centers represent a unique challenge to building managers. The stacks of servers require large amounts of energy to constantly run, while also emanating large amounts of heat into the room. The challenge is keeping energy costs low in a building while running a high energy-consuming, heat-producing data center at peak performance. As a building manager of a large data center, it is inevitable that the energy costs for cooling the building are likely the largest out of pocket cost each month. Despite the high cost of cooling, many building managers don’t focus enough on conducting proper planned maintenance of their HVAC systems. In order to save a significant amount in monthly energy expenses and long-term equipment bills, building managers should make a business-focused new year’s resolution to create or revive their planned maintenance schedule for HVAC.

According to the American Society of Heating, Refrigerating, and Air Conditioning (ASHRAE) the standard data center requires room conditions to be between 18 and 27 degrees Celsius (64 to 81 degrees Fahrenheit), with a dew point between -9 and 15 degrees Celsius, and relative humidity of 60 percent. The climate, heat output, building construction and makeup of the data center are just some of the numerous variables that make maintaining a room within those conditions both difficult and costly. The heat output of a data center is proportional to the combined amount of computing output and data storage capabilities of the center and likewise, the interior climate conditions inside a data center affect the efficiency of data transfer and server operation. When the HVAC system servicing a data center struggles to maintain internal climate conditions it is at the detriment of both the performance of the servers inside the center as well as the energy consumption of the building.

Maintaining an efficient and healthy HVAC system performance is one of the best approaches to counteracting potentially expensive data center costs. This level of system maintenance can be difficult depending on the demand put on the HVAC system. The interior climate demands in a data center are stringent and they require year-round HVAC performance, but they are also consistent. Unlike human-occupied spaces in a building that can have varying cooling demands, the heat output of a data center is relatively constant. The consistency of the heating load inside a data center provides a unique opportunity for building managers and plant owners to optimize their system to fit the needs of the data center while requiring the least amount of energy to run.

Planned maintenance of the HVAC system serving a data center is a crucial aspect of building management. Periodically scheduled cleanings of system components pay significant dividends in energy savings for an HVAC system. Chillers, coils and other components become clogged with material over time, reducing efficiency and drastically increasing costs.

A hydronic HVAC system or large chilled water system with a significant buildup of limescale and other water formed deposits will have to work significantly harder to maintain the room conditions of a data center. Scale deposits attach to the chiller tube walls, cooler tower piping, and other water-filled components of Hydronic and chilled water systems and reduce the heat exchange properties of the system, as well as the cross-sectional area available for fluids to flow through. This ultimately requires more energy for heat transfer and more power to propel the fluid through the system. Even a small-scale buildup inside pipes can require significantly more energy to cool a space. Additionally, for large HVAC spaces with constant use, a buildup of limescale can degrade the same components of and hydronic and chilled water HVAC systems, drastically reducing their effectiveness and decreasing their usable life.  Large data centers require the greatest cooling effort, and degradations will cause losses in the tens of thousands of dollars. Building managers can calculate their true cost of HVAC scale by using one of the descaling calculators at goodway.com/resources/calculators.

For systems where scale is not the issue, like Packaged HVAC system or RTU’s, scheduling the cleaning of coils is essential to maintain optimal temperatures. Wasted energy can cost between $1,000 and $3,700 per unit. Dirty coils can diminish heat transfer and increase operating temperatures and pressures. The importance to wash and flush both sides of the coils can be the difference between a data center overheating and shutting down or maintaining proper temperature and continuous power. Solutions, like the ones from Goodway, are specifically designed to clean coils. Just as cleaning the coils of such units the maintenance of cleaning the condensate drainage is consequential. Clogged condensate drain lines prevent water and other liquids from effectively moving out of the unit which can in time cause damage to the unit and surrounding area.

A comprehensive preventative maintenance plan is the single greatest method to minimize efficiency losses throughout the year. If building managers don’t already have a plan in place to maintain the efficiency and effectiveness of the HVAC system cooling their data center, they should implement one immediately. Maintenance plans can easily be synchronized with the calendar so that starting with the new year each maintenance plan becomes a new year’s resolution for HVAC efficiency. Setting a new year’s resolution is an effective way of making a permanent change for the future, and for a data center, a permanent change to regularly scheduled maintenance can produce savings throughout the life of the system. For specific problems such as system descaling, there are simple solutions such as Goodway’s ScaleBreak Liquid Descaler. Goodway’s line of ScaleBreak products safely dissolve mineral deposits inside your system components quickly and safely. The ScaleBreak Liquid Descaler is a low cost and effective method for achieving your new year’s resolution to carry out system maintenance.

Next Steps

Check out more information on these products at goodway.com/accessories/descaling-chemicals-accessories.

Pollution Control in Boilers

In recent years (data available to 2017), the United States saw significant improvements in air quality across the entire country. All of the major pollutants decreased in concentration over the study period including sulfur dioxide (SO2) down 79%, nitrogen dioxide (NOx) down 35%, and PM2.5 particles down 41%. The United States achieved these reductions through new environmental legislation, enforcement of existing laws like the Clean Air Act, and the advancement of pollution control technologies all while the nation’s economy grew and industrial capacity expanded.

As identified in an Environmental Protection Agency (EPA) report, a major source of air pollution is the burning of fossil fuels in industrial factories or boilers for power generation. The EPA warns that residuals from burning coal (coal ash) are “one of the largest types of industrial waste generated in the United States.” Burning coal is an inherently dirty process and federal limits restrict the concentrations of SO2, NOx, and PM2.5 discharged to the atmosphere. Modern boiler design and pollution reduction technologies are available so that plants can provide heat or electrical power at reasonable costs while still being compliant with environmental regulations.

Pollution control in coal-fired boilers can occur at all stages of the combustion process: pre-combustion, during combustion, and post-combustion.

Pre-Combustion

The selection of fuel to burn in the boiler is the first opportunity to reduce flue gas contaminants. For example, natural gas burns cleaner than fuel oil, medical waste, or biomass and produces the least amount of pollutants in its flue gas. Natural gas is considered a low-nitrogen fuel and yields very little NOx as a by-product of combustion. Also, as the EPA notes in its technical bulletin on controlling NOx that “natural gas is desulfurized before it is sent in a pipeline. Therefore, natural gas has almost no sulfur, essentially no impurities, and no ash.”

During combustion

The moment fuel and air ignite presents an opportunity to fine-tune the stoichiometry of the combustion process and the by-products of that reaction. With flue gas recirculation (FGR) a portion of the flue gas is sent back to the combustion chamber diluting the oxygen level of the combustion air, reducing the core flame temperature. The reduced temperature lowers the NOx level in the flue gases to below 20%. Cleaver-Brooks describes FGR as “the most effective and popular low NOx technology for firetube and watertube boilers. “

A fluidized bed recirculation (FBR) boiler burns crushed coal, wood or other low-grade fuels sitting on a sand bed within the boiler fireside. Combustion air is blown up through the bottom of the sand bed and mixes with the fuel on top of the sand where combustion occurs. This boiler design results in a fast mix of air and fuel and encourages rapid heat transfer. The burning environment gives a cleaner burn with reduced quantities of NOx and SO2 in the flue gases. SO2 emissions can be reduced further by introducing pulverized limestone into the combustion chamber. Sulfur in the flue gasses reacts with the limestone to form gypsum that, when separated from the fly ash, can be used to make other saleable products.

Post-Combustion

Coal ash leaving the combustion chamber can be captured and particulate pollutants removed before being released to the atmosphere.

One method for capturing fine particles like PM2.5 is to pass boiler flue gases through an electrostatic precipitator (ESP). With an ESP the flue gas flows across high-voltage wires that electrically charge fine particles suspended in the gas. The charged particles are attracted to a collection electrode, such as a series of metal pipes or plates, and accumulate on the electrode surface. ESP’s remove more than 95% of PM2.5 particles from coal flue gas and more complex ESP systems have removal efficiencies approaching 99%. To maintain such high levels, the collection electrodes should be cleaned per the manufacturer’s recommendations to minimize the thickness of fly ash buildup on the surface.

Cyclonic or cyclone fly ash separators (not to be confused with a cyclone furnace) are another method to remove fine particles from coal boiler flue gas. A cyclone separator works by blowing flue gasses against the interior wall of a cylindrical vessel. The gas enters the vessel near the top and circulates inside like a tornado. The centrifugal forces of the rotating flue gas push the fine particles to the outside of the “tornado.” The particles hit the interior surface and fall to the bottom to be collected while clean flue gas exits the vessel at the top. Although the efficiency of a cyclone separator may reach 90%, they are rarely used alone to meet EPA standards for particulate discharge. Most cyclone separators are used in conjunction with other technology like an FBR boiler to achieve the desired particulate concentrations. The clean flue gas can be analyzed to provide insight into the overall efficiency of the boiler and heat transfer processes inside.

The EPA’s 2018 report Our Clean Air summarizes things nicely, “The U.S. leads the world in having clean air and a strong economy due to implementation of the Clean Air Act and technological advancements from American innovators.” The power industry, pollution control manufacturers, and the EPA have a strong record of working together to create reliable electrical power while reducing atmospheric contaminants and improving the quality of the air we .

Power plant maintenance involves not only cleaning the boilers and chimneys, but servicing the heat exchangers, chillers, and condensers throughout the facility. In fuel storage areas, vacuums and power tools need to have explosion-proof motors to protect people from the dangers of coal and wood dust. Goodway offers a variety of power plant maintenance technologies that are safe and easy for technicians to use in any area of the plant.

Recording Available! Webinar: Industrial Boiler Cleaning

Goodway’s free webinar, “Industrial Boiler Cleaning” is available. The webinar host, Mark Roth, Goodway sales director, with guest Ray Field, Goodway’s director chemical technologies, walk through the basics of industrial boilers, the importance of cleaning and preventative maintenance, how to determine whether mechanical or chemical cleaning is the best solution for your facility, and the process for performing those cleaning options. There is also a question and answer session at the end of the webinar. Don’t miss this important webinar!

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Keeping High Performance Student Athletes Safer with Goodway

CBS Sports released a 2016 report detailing how three of the nation’s largest colleges earn and spend money from their sports programs. During the 2014-2015 season, Ohio State made $52,000,000 from football ticket sales alone. With 130 players on the football roster, hypothetically each player brought in $400,000 of revenue for the school. With so much revenue per football player, there is even more incentive to make sure student athletes don’t get sick because of something preventable, like athlete’s foot in the shower or a bad cough from mold in the training center air conditioning.

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Infographic-Products for Your Utility Plant’s Condenser Tubes

Preventative maintenance on condenser tubes is crucial. Dirty, scaled condenser tubes can negatively impact efficiency and tube lifespan. This can cost a plant money and productivity. Download this infographic to see the comprehensive suite of products Goodway Technologies provides to clean, descale and maintain your utility plant’s condenser tubes.

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