Heat exchanger technology aiding transition to sustainable future

Heat exchanger insights

• With growing focus on optimizing HVAC systems to maximize efficiency, heat exchangers are poised to play an increasingly significant role in promoting energy conservation and reducing carbon emissions.
• Decarbonization — a growing focus in the HVAC industry — is driving mechanical engineers to explore different technologies.

Technology is at the core of the built environment’s transition to a sustainable, net zero future. While it’s evident that new processes and technologies will need to be developed as the commercial building industry evolves, viable solutions to enable energy-efficiency improvements already exist. Industry professionals can expect to see these existing technologies evolve and applied in new ways.

Heat exchangers are among those existing solutions. Used in a variety of applications, heat exchangers’ primary role is to transfer heat from one fluid or gas to another to control the temperature of a system and capture and use waste heat. They are a vital component for providing economical chilled water for air conditioning to structures like office buildings, hospitals and especially data center cooling.

With growing focus on optimizing heating, ventilation and air conditioning (HVAC) systems to maximize efficiency, heat exchangers are poised to play an increasingly significant role in promoting energy conservation and reducing carbon emissions, aligning with the rising demand for sustainable and eco-friendly technologies. As a result, the heat exchanger market is anticipated to grow substantially in the coming years.

Specific to commercial buildings, plate heat exchangers are used in a host of applications, including free cooling, heat recovery, hybrid heat pumps, domestic hot water and hydronic heating and cooling.

When outside air temperatures are colder, cooling towers can cool condenser water and therefore the chilled water loop via the heat exchanger, allowing the electric chiller to remain off. Temperature crosses and approach temperatures as low as 2°F or 3°F typically are economically viable and produce a reasonable payback.

Beyond free-cooling and waterside economizer applications, increased development and application of various heat pump technologies are creating an opportunity for different applications of heat exchangers.

Figure 1: Small in size, lightweight and highly efficient gasketed plate heat exchangers like the GPX model meet a wide variety of applications like waterside economizers, thermal storage and district heating and cooling. Courtesy: Xylem/Bell & Gossett

Heat exchanger challenges and advancements

Realizing heat exchangers’ significant potential to reduce energy consumption, the commercial building industry is exploring how it can take advantage of this equipment to lower carbon footprint amid growing environmental concerns and regulations.

As states enact stricter regulations for HVAC energy efficiency and building owners realize cost savings and operational efficiencies with free cooling practices, heat exchangers and waterside economizers are playing an increasingly important role in sustainable HVAC system design.

With recent advancements in materials and design, gasketed plate heat exchangers are more energy efficient than ever before.

For instance, modern gasketed plate heat exchangers have features that provide improved media flow and greater use of the heat transfer surface area. This allows building operators to reuse energy that would have otherwise gone to waste, reducing energy consumption and related emissions costs.

Plate design has undergone innovation that greatly increases thermal and hydraulic performance. These advancements require less energy to heat or cool the liquid before it enters the heat exchanger, reducing overall operating expenses. Additionally, with improved flow of media across the plate and better use of the heat transfer surface, building operators can use a plate heat exchanger with fewer plates than before.

Gasketed plate exchangers used in free cooling applications can get very large in physical size. A more compact heat exchanger design can reduce installation costs when replacing older technology or expanding mechanical room capacity.

Regardless of new design innovations, ASHRAE Standard 90.1: Energy Standard for Buildings Except Low-Rise Residential Buildings requires certification for plates used in liquid-to-liquid heat exchangers. Certification provides assurance that the equipment will perform accurately and consistently and ensures all manufacturers are designing to the same tolerances.

The Air-Conditioning, Heating and Refrigeration Institute’s (AHRI) liquid to liquid heat exchanger certification program is based on AHRI Standard 400 for gasketed plate and frame type heat exchangers. ASHRAE 90.1-2010 or newer editions require waterside economizers to comply with AHRI Standard 400.

Adding value to hydronic systems via heat exchangers

With an ever-increasing focus on reducing energy consumption, designers and contractors are focusing on mechanical room optimization, including equipment selection like compact heat exchangers to enhance system performance and minimize system footprint.

Going forward, industry experts anticipate substantial growth in the heat exchanger market as the commercial building sector continues to embrace sustainable solutions for modern heating and cooling applications. Demand for gasketed plate heat exchangers, which has emerged as the primary technology for heat transfer, is expected to be particularly strong due to their high energy efficiency, small size and low cost.

Do you have experience and expertise with the topics mentioned in this content? You should consider contributing to our CFE Media editorial team and getting the recognition you and your company deserve. Click here to start this process.