Mid-Winter Energy Saving Tips – BuildingIQ

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January 11, 2018
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Mid-Winter Energy Saving Tips

The 2017 winter season to date has been severe, most recently hitting the east coast of the United States with freezing temperatures that extended all the way down to Florida. Whether you have a building that is in full heating mode, or are ramping up efforts as needed based on cold fronts, there are certain actions that can be taken to ensure that unnecessary energy leaks aren’t occurring. Below are a few tips for lowering winter energy costs in commercial buildings:

Check for Simultaneous Heating and Cooling

Simultaneous heating and cooling can create a major energy drain on a building. When this happens, air is being cooled in one part of the HVAC equipment and heated up in a different part of the system – wasting energy. This can present itself in a couple different ways.

Let’s use a building that has a chiller and boiler system as an example. It’s possible with this configuration to have both chilled water valves and hot water valves in the air handling unit (AHU). Chilled water is supplied by the chiller, hot water from the boiler. With a typical AHU set up, the cooling coil is located before the heating coil within the system. It’s important to double-check the valves. If both valves are open, water is being cooled and then heated – creating avoidable stress on the system and wasting energy.

The occurrence of heating and cooling at the same time is harder to detect in a Variable Air Volume (VAV) system. With this set up, heating is not in the AHU, but rather in the VAV. Building data is needed to determine if there is cooling occurring at the AHU level, while VASs are trying to warm up the air. With our 5i platform monitoring an HVAC, this type of fault can be clearly identified and easily fixed.

Utilize Free Cooling (If You Can)

Even in the winter, some cooling might be required to keep a building at a comfortable temperature for occupants. This can happen for a variety for reasons. For instance, the equipment within a building or a high occupancy rate caused by a special event may create a large thermal load to offset. If the conditions allow, it’s always economical to utilize free cooling or outside air. This is commonly done with an economizer.

Temperature and humidity conditions both need to be within the correct ranges for an economizer to be utilized. In general, conditions favor economizing when outside temperatures are between 40 and 60 degrees. If below 40 degrees, utilizing free cooling can cause problems such as freeze damage to equipment. When an economizer is not working properly, it can not only create a drain on energy, but also prevent a building from reaching its targeted temperatures. If you feel an economizer is not working properly, it best to check that the programming sequence it utilizes is implemented properly and that the damper is not being inhibited due to mechanical issues.

Raise the Chiller Temperature Set Point

It’s recommended to turn off the chiller plant during heating months if you can. However, this not always possible as some geographies or circumstances might require mechanical cooling. For instance, in Nevada temperatures drop in winter, but not low enough to turn off the chiller plant. In these scenarios, it may be beneficial to increase the temperature set point of the chiller so that it doesn’t have to work as hard. Raising the set points will save energy and will also avoid overcooling within the system.

Make Sure Thermostats Are Tuned for the Season

Lastly, make sure your thermostats are properly tuned for winter as this will help prevent any major overheating. Suggested ranges from the ASHRAE are 68 to 74 degrees during the winter. While this may be a large drop, it’s important to remember that tenants tend to wear thicker clothing during the cooler months to account for the change in weather. For buildings that have tenants controlling the thermostats, it is worth suggesting that this temperature range is implemented. Otherwise, adjusting set points is a fairly easy task that a facility manager can make.

These are just a few tricks to keep energy costs low during winter months. Our 5i platform can be used to identify these listed faults and more complex energy drains that can only be discovered through trends in data. Shoot us an email to learn more, and in the meantime, stay warm!


 

Dr. Estatio Gutierrez is Director of Optimization at BuildingIQ. Estatio obtained his Doctor of Philosophy (PhD), Mechanical Engineering in 2015. The focus of his dissertation was urban weather modeling focused on the impacts of air conditioning systems in the urban environment. He also has studies in atmospheric sciences and meteorology.