Recycled heat cuts ripening room costs at Warmerdam
Recycled heat cuts ripening room costs at Warmerdam
HANFORD, CA -- Warmerdam Packing LLC, here, has developed an innovative way to heat its stone fruit ripening rooms and reduce the cost of operating the rooms in the process. It uses waste heat generated by the existing refrigeration systems used for cooling in the company's cold-storage facility.
"Our whole industry here in the Central [San Joaquin] Valley has been doing different forms of preconditioning or ripening of stone fruit," said Mr. Hovsepian.
Like other companies, Warmerdam has been doing some ripening and had been using some of its cold rooms, which were also used for controlled- atmosphere storage, for its ripening program. It worked well on the whole, but there were some challenges.
"There are a lot of variables to consider when properly ripening fruit," he said. Those include "fruit pressures, fruit temperatures, soluble solids, time in ripening room at specific temperatures, humidity and a variety of things that can influence successful ripening of fruit."
The cold rooms at the Warmerdam facility are generally kept at about 33 degrees, but when any of the rooms are used for ripening or preconditioning of tree fruit, they need to be held between 68 and 72 degrees. Warmerdam attempted to achieve that by bringing in hot air from outside but found it difficult to maintain a constant temperature, Mr. Hovsepian said. "We were struggling" to keep the rooms at the correct temperature for ripening "in the middle of a cold-storage facility that is normally set at 33 degrees."
To find a solution to that problem, the company considered several more conventional forms of heat. "We looked at electrical heat, natural gas and other forms of heat most people are using to bring heat into the room to ripen fruit," he said. "All those cost quite a bit of money."
After doing "our homework on costs of units and related energy costs," he said, "we decided to try a creative way to use some of our existing equipment and the hot gas from the high side of our ammonia refrigerant system. This heat is generally considered waste heat that is expelled to the atmosphere through our evaporative condensers."
Warmerdam approached its refrigeration company, California Controlled Atmosphere, to enlist its help in designing a system that would save energy by "capturing waste heat to use in our ripening rooms," Mr. Hovsepian said. The concept was to develop a system "that would use either hot gas to warm a room or liquid ammonia [running through the same coils] to cool a room." The company also approached the utility company PG&E about getting a rebate on the project.
"It was a long, hard process" from design to review to approval and finally to installation, Mr. Hovsepian said. "We had to show PG&E that our creativity was indeed a good idea that would save energy."
Eventually, PG&E came through with an "incentive" rebate check that covered more than one-third of the cost of the project. In addition, Warmerdam expects to achieve considerable energy savings by utilizing the waste heat vs. paying for electricity, natural gas or propane to heat the rooms.
The engineering wasn't simple by any means, and neither was installing the necessary piping. But once installed, the operation of the rooms is extremely simple, he said. Switching a room from cooling mode to heating mode is "as simple as turning a switch on and off."
The company currently has two "very versatile" rooms set up that can be used for preconditioning, cold storage or controlled-atmosphere storage depending on the need at the time. Each room can handle about 15,000 boxes of fruit. The two rooms were in operation during the 2006 stone fruit season, and the process worked well, Mr. Hovsepian said. "It was not an easy process, but we are very happy with the end result. We try hard here at Warmerdam's to be energy-efficient and do things right."
The company has a long history of finding innovative ways to save energy and is currently looking at some additional methods for cutting energy costs.
"Our whole industry here in the Central [San Joaquin] Valley has been doing different forms of preconditioning or ripening of stone fruit," said Mr. Hovsepian.
Like other companies, Warmerdam has been doing some ripening and had been using some of its cold rooms, which were also used for controlled- atmosphere storage, for its ripening program. It worked well on the whole, but there were some challenges.
"There are a lot of variables to consider when properly ripening fruit," he said. Those include "fruit pressures, fruit temperatures, soluble solids, time in ripening room at specific temperatures, humidity and a variety of things that can influence successful ripening of fruit."
The cold rooms at the Warmerdam facility are generally kept at about 33 degrees, but when any of the rooms are used for ripening or preconditioning of tree fruit, they need to be held between 68 and 72 degrees. Warmerdam attempted to achieve that by bringing in hot air from outside but found it difficult to maintain a constant temperature, Mr. Hovsepian said. "We were struggling" to keep the rooms at the correct temperature for ripening "in the middle of a cold-storage facility that is normally set at 33 degrees."
To find a solution to that problem, the company considered several more conventional forms of heat. "We looked at electrical heat, natural gas and other forms of heat most people are using to bring heat into the room to ripen fruit," he said. "All those cost quite a bit of money."
After doing "our homework on costs of units and related energy costs," he said, "we decided to try a creative way to use some of our existing equipment and the hot gas from the high side of our ammonia refrigerant system. This heat is generally considered waste heat that is expelled to the atmosphere through our evaporative condensers."
Warmerdam approached its refrigeration company, California Controlled Atmosphere, to enlist its help in designing a system that would save energy by "capturing waste heat to use in our ripening rooms," Mr. Hovsepian said. The concept was to develop a system "that would use either hot gas to warm a room or liquid ammonia [running through the same coils] to cool a room." The company also approached the utility company PG&E about getting a rebate on the project.
"It was a long, hard process" from design to review to approval and finally to installation, Mr. Hovsepian said. "We had to show PG&E that our creativity was indeed a good idea that would save energy."
Eventually, PG&E came through with an "incentive" rebate check that covered more than one-third of the cost of the project. In addition, Warmerdam expects to achieve considerable energy savings by utilizing the waste heat vs. paying for electricity, natural gas or propane to heat the rooms.
The engineering wasn't simple by any means, and neither was installing the necessary piping. But once installed, the operation of the rooms is extremely simple, he said. Switching a room from cooling mode to heating mode is "as simple as turning a switch on and off."
The company currently has two "very versatile" rooms set up that can be used for preconditioning, cold storage or controlled-atmosphere storage depending on the need at the time. Each room can handle about 15,000 boxes of fruit. The two rooms were in operation during the 2006 stone fruit season, and the process worked well, Mr. Hovsepian said. "It was not an easy process, but we are very happy with the end result. We try hard here at Warmerdam's to be energy-efficient and do things right."
The company has a long history of finding innovative ways to save energy and is currently looking at some additional methods for cutting energy costs.
