Conventional HVAC design uses separate systems for heating and cooling, each optimized for performance during peak seasonal weather conditions. Typically, heating and cooling are considered as separate entities that are opposite of each other, but according to Jeff Weston, this methodology is fundamentally flawed.
“You can’t heat something without cooling something else, meaning all heating or cooling is simultaneously heating and cooling.” says Weston. In 2005, this insight led Weston, through his company, Thermenex, to develop a patented system called a Thermal Gradient Header (TGH), a single pipe to integrate all thermal systems together. The continuous pipe is filled with water or glycol and has a hot and a cold end with multiple variable-temperature zones in between.
“Many HVAC design professionals are starting to develop ‘integrated designs’ that use chillers for both hot and cold temperatures and are reclaiming heat instead of expelling thermal energy as waste. What many are learning the hard way is that many of the old standards and rules of thumb no longer apply and need to be unlearned. If not, they will unknowingly design systems that struggle.”
Systems which are too complex, use too much electric energy or offer poor control of energy flow, often miss performance targets and create dissatisfied clients. Traditional HVAC thinking of hot and cold as opposites, misses the benefits of reclaiming energy by using the same components for both heating and cooling systems.
“The amount of infrastructure required is reduced because most major components are used for both heating and cooling. Not only that, but the purchased energy consumption is also significantly reduced because we can now optimize the utilization of the free thermal energy already in the building.”
At the core of the Thermenex system is the principle that every chiller is also a heater. A refrigerator, for example, cools food by transferring thermal energy to its surroundings, effectively heating the kitchen.
The Thermal Gradient Header approach involves lowering heating temperatures to use for cooling and raising cooling temperatures to use for heating. This overlap allows for a single system to handle both heating and cooling needs. The result is an elegant, efficient solution that dramatically reduces gas and energy usage.
“Thermenex has proven results, with some buildings achieving over 90% reduction in gas usage and up to 75% reduction in total purchased energy. Our innovative system has been successfully implemented in numerous projects, especially in healthcare facilities across British Columbia,” Weston says.
Thermenex is now working with owners and engineers to design, build and operate reliable HVAC systems that minimize resource waste and create truly sustainable buildings.
“We’ve completed five projects for one health authority and are working on six for another,” says Weston. “Our clients have seen significant benefits from our system. Healthcare facilities are not only reducing their carbon footprint but also cutting their energy consumption and reducing their operating costs.”
Providence Health Care, with major facilities in Vancouver, and Island Health, which oversees all hospitals on Vancouver Island, have become staunch supporters of Thermenex’s system.
“PHC’s government mandated target is a 50% reduction in GHG emissions by 2030, but due to the promise shown by the Thermenex system, we decided to set ourselves a stretch goal of reaching 80% by 2023 for the majority of our buildings. Three of these facilities are successfully achieving over 80% reduction in annual GHG emissions, with two over 90%, which is very impressive performance indeed. The remaining TGH system will come online later in 2024, and I expect to see similar results in energy efficiency and emissions reduction.” – Tony Munster, Providence Health Care
“I have worked at decarbonizing healthcare facilities for 10 years. None of the other heat recovery solutions have come close to the achieving results like the TGH technology. Recently I have worked with Thermenex on five projects and the solutions being developed are saving millions in capital cost with operational cost savings to come.” – Ryan Galloway, Island Health
Overcoming Skepticism
Despite the proven success, encouraging the broader HVAC industry to adopt this novel approach has been challenging. Which is not surprising given the human tendency to resist paradigm shifts.
“Our industry has trained designers to think of heating and cooling as separate processes,” explains Weston. “It took me 20 years to realize there was a different way, and another 15 years to change my knowledge enough to perfect it. This change doesn’t make sense using traditional HVAC knowledge, but many owners are starting to see the benefits and are pushing for this innovative solution.”
The Future of HVAC: Thermalization Before Electrification
In the push towards sustainability, many in the building industry are advocating for full electrification. Weston believes that thermalization, the process of switching from purchased energy resources to free thermal energy resources, should come first.
Thermenex’s belief, “Thermalization before electrification,” encapsulates this philosophy. By prioritizing the efficient use of thermal energy inherent in our environment, buildings can achieve near-zero carbon emissions with less electricity usage which makes getting to zero carbon much easier.
With a track record of success in healthcare facilities and the potential to revolutionize the way we think about energy efficiency, what’s next? As a continuous innovator, Westons says, “We developed a way to incorporate free cooling at peak summer. Future clients will not only be able to get energy savings with a reduced carbon footprint, but also get through heat dome events without adding more chillers.”
To learn more, visit www.thermenex.com
CHES National Convention Booth 98
