DunAn Microstaq Inc.’s HC-MSEV USHC Retrofit Kit was developed for commercial HVACR systems with 10 to 25 tons of cooling capacity. The primary function is to improve evaporator efficiency by controlling superheat toward a target setting quickly and precisely. This tight, continuous control of superheat under dynamic heat load conditions enables optimal system performance, lessening the work for the compressor and translating to improved system efficiency. It’s these design qualities that netted the retrofit kit the gold award in the HVAC Light Commercial Equipment category of this year’s Dealer Design Awards contest.

“The kit comprises an expansion valve and integrated controller,” said Parthi Arunasalam, CEO, DunAn Microstaq. “The integrated controller is different because it’s truly integrated — it has a pressure sensor, temperature sensor, and machine intelligence all embedded into a palm-size package. There are lots of amazing valves on the market. The catch is finding a valve and controller that can be used across a variety of refrigerants without the end user trying to figure out how to configure or program it. These controllers already come with four default refrigerants and can be expanded up to 18 different refrigerants. And the nice thing about it is that a customer or contractor looking at new refrigerants about to be delivered into the market can ask us to embed the new refrigerant characteristics to try with the controller.”

The HC-MSEV USHC Retrofit Kit is a stand-alone, drop-in replacement for an existing thermostatic expansion valve (TXV) or an electronic expansion valve (EEV). The High Capacity Modular Silicon Expansion Valve (HC-MSEV) has a 500-millisecond response time. It utilizes a Micro Electro Mechanical System (MEMS Module) as a pilot valve and a spool valve for the second stage. Weighing 17.6 ounces, all valve models from 10 to 25 tons share the same physical package. With only three moving parts, it has very high reliability compared with a TXV or an EXV of stepper motor design.

“I’ve used this in a number of different projects,” said Kipp Bradford, president, Kippkits LLC, Pawtucket, Rhode Island. “One of the things that was super-important to me was the ability to control the expansion valve in software. So, that means tying into our controllers and then dialing in to not just superheat, but understanding the way the system is behaving by looking at the pressures, temperatures, and controlling the flow of the refrigerant with an external controller. We’ve had good success with it. I love these things. I can’t say enough about them.”

Bill Crist, engineer, DC Engineering, Missoula, Montana, has been experimenting with the retrofit kit in his office and in the field for about a year.

“We’re comparing several different manufacturers to find the most suitable valve for our client,” he said. “The DMQ [DunAn Microstaq] is the only valve that’s not a stepper motor. One of the nice features of it is when you remove the power, it shuts instantly.”

The company does have plans in the works to further enhance the product by releasing a kit that goes from 1 to 8 tons, Arunasalam said.

“The last time we won a DDA gold award in 2015, it opened a lot of doors for us and gave us recognition,” he said. “Customers we didn’t know existed got in touch with us. In all sense, it’s good for business. We couldn’t be happier winning this award.”


Lennox Intl. Inc. earned the silver award with its VRF Medium-Static Ducted Indoor Unit. The VMDB ducted indoor unit offers a more traditional look in the space while still benefiting from the efficiency and comfort of a VRF system. Instead of a single long filter media, the VMDB’s washable filter is built into three sections, connected by hinges. This allows the technician to fold the filter as it is pulled out for maintenance. Additionally, filter access on both sides of the unit simplifies on-site decisions on unit location and gives more flexibility to the service technician.

“We started talking about new features and functions back in 2015, then started active development in 2016,” said Pam Duffy, senior product manager - VRF, mini-splits, DOAS, Lennox.

Duffy said Lennox is trying to find little things that make a big difference, such as adding additional labeling to make it even more clear about how to go about installing the product.

“We’re really excited about the new sectional filter that allows the contractor to pull it out on either side — it’s different and unique,” she said. “We’ve also incorporated all service codes for the unit into the wired controller, so if there is ever an issue, the technician or facility manager doesn’t have to pop into the wall to figure out what is going on — they can troubleshoot from the ground, looking at the controller. And it’s behind a password-protected screen, so the average user can’t get confused by that data.”


The Sensi™ Multiple Thermostat Manager from Emerson, which was introduced in February, earned the bronze distinction. It is a software application that can manage and control multiple heating and cooling systems through one online portal. Two years of research went into the development in order to ensure the system is tailored to the users’ needs.

“A lot of products out there today are full of features many people don’t actually use that just complicate the user experience,” said Abhishek Chakravarty, product leader, Sensi Multiple Thermostat Manager, Emerson Commercial & Residential Solutions. “We really did not want to go that way. We took the time to get this right.”

The product is also easy to use, with “drag and drop” functionality to create and manage groups of thermostats. Thermostats can be locked and unlocked individually or in groups to prevent tampering and to control heating and cooling costs. Thermostats can also be changed in batches and can be monitored in real time.

“The most important thing is ease of use and user experience,” Chakravarty said. “We wanted to make this product so easy to use that anybody who has no idea about HVAC can manage and use the product.”

Publication date: 7/23/2018

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