How Lennox is working to overhaul the HVAC industry with new technology

In late 2021, the U.S. Department of Energy will ask HVAC industry leaders to heat and cool homes better by improving heat pumps that move existing air in and out of homes, rather than creating new sources of heat or cold. I requested that it be efficient and cost effective. air.

According to the DOE, air conditioning and hot water accounts for 46% of building emissions and more than 40% of the primary energy used in American residential and commercial buildings. It also accounts for 42% of all building utility costs and 56% of household utility costs annually.

What is the purpose of the challenge? Create a cold-weather heat pump that can heat homes in the northern United States, where winter temperatures create high energy demands. Estimated cost savings can reach up to $500 per household per year.

Nine companies jumped at the challenge, with Richardson-based Lennox being the first to unveil an approved prototype this summer. Prakash Bedapudi, Chief Technology Officer at Lennox, said: “We wanted to be the first to meet that challenge.”

Here, Bedapudi discusses how Lennox’s new prototype seeks to solve a long-standing problem in energy, its potential implications, and next steps in the challenge.

D. HaEO: What issues did the U.S. Department of Energy want to address with this challenge?

Bedapdi: “If you need heating in your house in the winter, you usually run a gas or propane furnace in your house. Furnace system.

“Then, what is a heat pump? A heat pump is basically the same as an air conditioner, but it requires valves and piping that switch the cycle 180 degrees. Pick it up and project it inside your home, which means it can heat your home instead of cooling it.

“Why not use a heat pump in a cold climate like Minneapolis or North Dakota? So, in essence, the heat pump’s capacity or ability to heat a house drops dramatically from a day with ambient temperatures of 40-50 degrees to a day with 0 degrees.

“So what about heating the house? Well, you can’t. You need a supplemental electrical strip heat boost. Even so, some parts of the country can experience zero or negative temperatures for six to seven months of the year, during which time heat pumps cannot be used, and electric strip heaters are notoriously inefficient. As an owner, it costs a lot of money to heat your home with electric strip heaters, which is why heat pumps haven’t gained momentum in cold climates.

“Today’s heat pumps stop working around 0 degrees Fahrenheit. No. Yields are going down.

“As an alternative, people burn gas furnaces. ) and given that macro trend, the U.S. Department of Energy turned to the HVAC industry and said, Hey, people are still burning tons of natural gas to heat their homes. Can we incentivize HVAC manufacturers to develop this cold weather technology?” In other words, “Can we improve the efficiency and capacity of heat pumps to minus 20 degrees?”

D. CEO: How did you propose to solve this problem in your prototype?

Bedapdi: “The human mind and the engineer’s mind is an amazing thing. Put that competitive spirit in, rekindle it, put in a timeline, and they’ll work day and night, and it’s a lot more fun than just a job.” So what we did was put it on a higher tier, which basically accelerated the overall progress of this project. I have taken on many other projects and devoted myself to this one.

“They looked at what was the key factor in adopting core performance. It has to come from running more compressor capacity. How do you do that? Steam We came up with the technology of injection, which is akin to getting more power out of a sports car, what do car companies do when they want to get more power out of an engine? or supercharge.Same concept.By introducing steam injection technology, the compressor is upsized.In essence, it gets higher mass flow rate and higher heat production overall in the heat pump cycle. We’re going to send more mass into the compressor so that we can do that, and that’s what we did.

“Then we put in a bigger heat exchanger. You have to put in place a control scheme to manage the machine with all the vapor compression and fans, expansion valves etc. This is a system design from scratch what are the key knobs to improve efficiency and capacity Once we understand that, we need to get it all ready and build a prototype to demonstrate that we can meet the challenges of efficiency and capacity levels.”

(d) Representative Director: What are the capacity requirements for challenges?

Bedapdi: “Today’s conventional heat pump produces, say, 100 units of heat at an ambient temperature of 50 degrees Fahrenheit. The goal for the ground heat pump was to get it down to 0 degrees F. The challenge was to keep the capacity flat, even zero would have to handle 100 units of heat.”

(d) Representative Director: What is the next step in your challenge?

Bedapdi: “We are currently running a few prototypes in our lab. Our next step is working closely with the DOE to identify four to six locations in very cold climates across the country. Could be South Dakota. No, it could be anywhere between DOE and us that it makes more sense to put these field test units in. So in the months before winter starts, We plan to build a minimum of 4 and possibly up to 6 field test units and install them in these climates.

“These units have a lot of gauges. You can get the data remotely so you can monitor the heat [the test units are] In terms of both capacity and efficiency, we will be able to demonstrate in the hands of some consumer homes that this cold climate heat pump provides the capacity and efficiency required for the challenge. “

(d) Representative Director: If all goes well, what will be the environmental impact of Lenox’s new cold-weather heat pump?

Bedapdi: “Field testing at this point will give more quantifiable results compared to conventional heat pumps or compared to gas-fired and AC systems operating in cold climates. The thermal efficiency improvement goes from 50 to 60, with a corresponding reduction in carbon footprint.”

(d) Representative Director: Once testing is complete, when can Lenox officially launch this product?

Bedapdi: “The product development cycle typically lasts 12 to 18 months, sometimes even earlier depending on market demand.”