Organizations in most any industry are interested in green building practices because they make sense on many levels, from saving on energy costs to reducing carbon emissions – and saving the planet. Transit systems such as metro stations should be no different, for the savings to be had are significant – and industrial UPSs can help them get there.
Reaching the Greenest of Green
Rating systems such as the Indian Green Building Council’s (IGBC) Green Mass Rapid Transit System (MRTS) and the U.S. Green Building Council’s Leadership in Energy & Environmental Design (LEED) for Transit provide frameworks that detail the design, construction and operation criteria that a transit system needs to meet to achieve various green ratings. They each have scoring systems that cover categories such as energy and water efficiency, indoor environmental quality, use of responsible materials, sustainable site development, and more.
The scores are calculated to determine different levels of green, including Certified, Silver, Gold and Platinum. Platinum, the highest level, is awarded to projects that meet all mandatory requirements and achieve at least 80% of the points across all categories. In essence, a Platinum recognition means a building is “the greenest of green.”
How Cooling Contributes to Energy Use – or Savings
One significant source of energy use in a transit facility is cooling. A metro station, for example, should have two general types of cooling: comfort cooling and precision cooling.
Comfort cooling is used in areas populated by the public or employees. As with any home or office building, such areas are generally maintained at temperatures around 22° to 24° C (72° to 75° F). The systems typically have a sensible heat ratio (SHR) of around 0.7. The SHR measures how much energy is used to cool the air (the sensible load) vs. how much is used to dehumidify the air. A rating of 0.7 means 70% of the load cools the air while the remaining 30% is used to dehumidify it.
Transit stations also have rooms solely for IT and related equipment, such as industrial UPSs (including batteries), electrical panels and the like. In these rooms, it’s possible to gain energy efficiencies using precision cooling, which are systems that ensure all cooling capacity is used to cool the equipment that needs cooling.
With precision cooling, it’s possible to get a SHR close to 1, which means all the energy capacity is used for cooling, not to remove humidity. A cooling system with an SHR of 1 is far more energy efficient than one with a rating of 0.7 – 30% more, to be exact. The room may be warmer than a public space, but so long as it’s within the tolerances of the IT equipment, that’s not a concern.
Lithium-ion Means Higher Temps for Industrial UPSs
IT equipment today can withstand far higher temperatures than in the past, with some data centers now using temperatures as high as 35° C. Similarly, industrial UPSs that use Lithium-ion (Li-ion) batteries can withstand far higher temperatures than UPSs with traditional valve regulated lead-acid (VRLA) batteries – up to 40°C (104°F) – with less effect on battery life.
Let’s say you have an equipment room with Li-ion industrial UPSs operating with precision cooling at a set temperature of 35° C, up from as low as 22° C. Each 1° C increase in the air-conditioning set point yields a 5% to 10% reduction in cooling energy use, which translates to a 2% to 5% reduction in overall energy use for the facility.
Given these IT rooms must be cooled 24×7, 365 days a year, such savings add up. By using precision cooling for IT rooms instead of comfort cooling, along with components such as Lithium-ion-based UPSs, a transit facility can reduce its energy costs for the room by approximately 56%.
Learn How to Make Your Transit Facility Greener
It’s the kind of approach that can mean the difference between a Platinum rating and a Gold or Silver, especially when coupled with other energy saving approaches such as under floor air distribution (UFAD) systems and UPS with Li-ion Batteries. If you want your transit facility to be the greenest of the green, learn more about these latest energy saving technologies. Also, access additional resources to understand how industrial UPSs can ensure business continuity and efficiencies for your facility.