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6 Ways to Make HVAC Systems as Green as Can Be

October 01, 2021

Technology and material advancements have been making buildings consistently more sustainable for decades. Some of what’s possible is truly remarkable. There are solutions readily available today that can reduce emissions while paying back building owners with financial benefits.

Here are six ways that HVAC systems can make bigger strides to decarbonize right now.

1.  Squeeze out every last kilowatt of inefficiency

The electric grid is still partially powered by carbon-emitting power sources. The first step to decarbonization begins by following some basic principles of applied system design. Decisions for compression-based heating systems should enable a high enough annualized COP to reduce emissions below site-based fossil fuel heating systems.

High efficiency systems further reduce wasted energy demand when the right control strategies are applied. As an example, Trane’s Symbio® 800 controller with Adaptive Controls modulates the compressor and fans to deliver peak efficiency at all operating conditions. When multiple units are in place, Tracer® SC+, with its chiller plant control application, can efficiently sequence units and dynamically adjust system control setpoints to minimize system energy use at all load conditions.

2.  Use cool outdoor air instead of the compressor

Nature often provides what we need, and contemporary solutions are getting quite clever (and sensible) about using the local climate or geo-based resources. One of the market’s most practical and readily-available solutions is Free Cooling. It uses outdoor air to chill water used within applied systems without the use of compressors when outside air temperatures are advantageous—during winter, spring and fall. Integrated free cooling, a technology that’s available in many Trane chillers, can make building cooling easier, more efficient, and lower cost than field-provided solutions.

3.  Recover and reuse heat energy

Many buildings require heating and cooling at the same time. We’ve all experienced buildings where some areas are too hot, while others feel too cold. Moving heat, instead of generating it with gas-fired heaters, reduces a building’s direct greenhouse gas emissions while improving comfort. Electronics, lighting and human bodies all generate heat which builds up in certain interior spaces. Heat recovery systems reclaim this excess heat energy that is typically expelled from the building and transfers it to different areas where heat is needed.

4.  Plan a transition to low GWP refrigerants

The U.S. EPA has proposed a new rule to limit hydrofluorocarbon (HFC) production based on global warming potential (GWP) in an effort to align with the Kigali Amendment to the Montreal Protocol and the AIM Act enacted last year. As part of the Trane Technologies Gigaton Challenge, Trane plans to fully transition out of high GWP refrigerants by 2030, ahead of regulation. What’s your next move? Consult with HVAC system experts now to begin strategizing your building’s transition to less harmful, next-generation refrigerants including R-513A, R-514A and R-1233zd.

5.  Store energy to help balance supply and demand

We’re all in this together. Buildings are part of the problem, and they have a responsibility to be part of the solution—a big part. Despite significant progress, buildings still account for over 70% of U.S. electricity consumption and power sector CO2 emissions.1 Along with continued efficiency strides, buildings also need to become more flexible in timing when they consume the most energy. Energy storage enables the shift, and in chiller plants that means ice storage: dedicating chillers to create cold energy at night, when electricity demand and prices are lower, for use in the peak-use daytime hours. Shifting building load helps to balance the grid’s electricity supply with customer demand—one of the key prerequisites to speeding up the grid’s full transition to renewable energy sources.

6.  Transition to renewables, onsite and offsite

When used in combination with HVAC system solutions that reduce or shift energy demand, renewable energy sources, such as solar and wind, can serve a significant part of a building’s energy demand. As utilities get greener, advanced chiller controls can integrate with services that allow two-way communication with the grid. Buildings that can reduce, shift, or modulate energy use and establish demand flexibility will expedite the reality of a fossil-fuel-free, renewable-energy grid.

Sustainability is complicated when you don’t have a plan, but the right partner can help you strategize with solutions that are proven, practical and affordable. When you need a partner to guide you into the next generation of decarbonization and building electrification, reach out to Trane.

U.S. Department of Energy, Office of Energy Efficiency & Renewable Energy, “A National Roadmap for Grid-Interactive Efficient Building.” May 2021. ( https://gebroadmap.lbl.gov/)