Interest in CO2 as a refrigerant for HVAC-R applications in the United States has increased substantially in the past 10 years or so. As new technology emerges seeking to capitalize on CO2's near-zero global warming potential (GWP), we wanted to hear what one SRC's CO2 experts thought about the practicality of some newer applications for the refrigerant. The conversation below is a clip from a larger discussion around the long-term viability of some emerging and potential HVAC-R applications for CO2, a.k.a. R-744. Listen to hear some comments from SRC's Southeast Regional Sales Manager Ken Allen on the pressures of CO2 and some other properties. 

That’s a wrap! The 2023 AHR Expo has come and gone. Super Radiator had a very busy show and we enjoyed seeing all the innovation and excitement on display in Atlanta this week. For this post, we thought we’d share our perspective on our show – the hot topics and near-term industry outlook, the show itself, and some perspective from SRC’s attendees.

The US started limiting HFC usage on January 1^st, 2022, following the passage of the American Innovation in Manufacturing (AIM) Act of December 2020. Prior to the legislation, the EPA did not have the authority to make changes to HFC usage, and HFC policy decisions fell largely to the states, 11 of which had already begun HFC phasedown measures under the US Climate Alliance. The EPA's current phasedown schedule is aiming to reduce the production and consumption of HFCs by 85% below baseline levels gradually by 2036. This means that individuals and organizations that currently use HFCs like R-404A, for example, have a decision to make. 

Well, 2022 is in the books, and in the HVAC-R industry, we all know what the new year brings – the AHR Expo and ASHRAE’s annual Winter Conference! And, after a somewhat scaled-back presence in 2022 due to the lingering pandemic, Super Radiator is excited to exhibit and attend as normal (booth #B2947).

In heat exchangers, circuiting refers to the pattern by which the working fluid travels from the coil’s supply to its return. Also relating to coil circuiting is the orientation in which the coil is installed, relative to the direction of the application’s airflow.

Coil circuiting and its relationship with the application’s airflow are critical considerations of coil design, as proper circuiting can help increase the heat transfer coefficient of the heat exchanger.

On the other hand, improper circuiting can lessen a coil’s effectiveness and even cause damage, like tube erosion resulting from insufficient calculations for fluid velocity, for example. So, it’s important to understand the forces at play before deciding on a circuiting layout.

With the explosive growth of the digital economy over the last quarter century, the need for services like data storage, large-scale immediate computing operations, web hosting, and others has exploded as well. In that time span, the data centers where these functions take place have mutated from a handful of on-premises server racks performing local operations to sprawling commercial structures with thousands of servers.

Our refrigerant focus series consists of deep dives into the history, properties, suitable applications and pros and cons of some of today’s common refrigerants. This installment will focus on R-448A.

• Refrigerant Focus #1: R-32
• Refrigerant Focus #2: R-410A
• Refrigerant Focus #3: R-1234ze
• Refrigerant Focus #4: R-407A
• Refrigerant Focus #5: R-290
• Refrigerant Focus #6: R-744 (CO2)
• Refrigerant Focus #8: R-454B

In the world of commercial HVAC-R systems, energy efficiency is paramount – whether your goal is to satisfy industry-mandated efficiency ratings or win customers by saving them money on their electric bill. Overall unit/system efficiency is what end users are after, but if you’re an OEM of commercial RTUs, AHUs, etc., and don’t have a deep understanding of how subcomponents - especially coils - impact unit efficiency, you could be costing your customers money – a lot of money.

Based on the experiment outlined in this article, poor coil design can lead to more than a 100% increase in annual fan electricity usage per coil per year.

To start, I’d like to say that this article is not intended to be political. I feel there are certain issues that transcend politics, and regardless of where you may fall on the political spectrum, some challenges can’t be met without cooperation. And I think one such challenge is ensuring our environment is healthy and sustainable for future generations.

Earlier this month, Congress passed the Inflation Reduction Act, which was signed into law by President Biden on August 16^th. The legislation, which is designed to – among other goals – help relieve Americans of rising healthcare, energy, and consumer costs, also includes $386 billion aimed at combatting climate change at several levels. As the leader of a manufacturing company, I’m excited to see that this investment in our climate is also an investment in American jobs, innovation, and engineering excellence.

At Super Radiator, some of our favorite projects are those that have a positive impact on the world around us. Take applications like economizers or waste heat recovery, for example. Coils designed for such purposes perform functions like harnessing otherwise wasted heat to reduce fuel costs or power other functions like heating water.

But, with some of these sorts of applications come some unique challenges. Since these applications often involve combustion – the fuel for which can take a variety of forms – accurately modeling the heat transfer properties of the resulting gas mixture (known as flue gas) requires extra care.