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PRESS
Excepts from an article in
Habitat Magazine — May 2003 – Number 190
by Tom Soter
BALANCING ACT
Co-op installs heat timers to save money
Call it a question of balance - both literally and figuratively. First, there is the issue of balancing temperatures in a large property. And then there's the issue of balancing shareholder cost concerns.
The Board President of 2 Tudor City Place, a 333-unit co-op in Manhattan, tackled the co-op's biggest problem, a common one in large residential buildings: apartments on one side of the structure were overheated, while those on the other were downright chilly. According to Edward Sarubbi, an engineer [with Leonard Powers, Inc.] who studied the double-building complex, "Each of the two buildings (north and south tower) operate as independent heating zones, each with its own heating control and motorized zone control valve. The south face of each tower has tremendous solar gain on sunny days while the north face is subject to prevailing north winds in the heating months." Both areas operated as a single zone, with no provision to adjust for these differences.
How to achieve balance? At a cost of $250,000, the building replaced its two aging, energy-losing boilers with new energy-efficient ones. The President convinced the board to replace them by arguing that the fuel and energy saved with new equipment would quickly give the building a return on its investment.
For eight years, Greg Fricke Jr. had owned Leonard Powers, a 70-year-old firm that specializes in dealing with problems relating to the control and distribution of steam. Coincidentally, the property's managing agent, Grogan Associates, had frequently worked with Leonard Powers on energy matters. The company sent Sarubbi in to evaluate the balancing issue.
Sarubbi offered this solution: "The south tower is piped so the southern and eastern exposures can be controlled via a new zone valve control and new heat control. The northern and part of the western exposures can be controlled via a second valve and control. The north tower piping makes it possible to zone this building with the western half controlled as one zone while the east side [is] controlled as a second zone."
The engineer also suggested upgrading the type of controls used to regulate the heat levels, one that involved two sensors. One sensor would register outside temperature while the second could be a temperature reading "from an apartment for the referenced zone or from the condensate return piping from the respective zone." The system to be used is "a microprocessor-based digital control with...an optional remote communication from a local PC or via [a] modem. These controls are expandable if future sensor outputs are wanted or if other control points are to be interlocked."
In addition, the engineer recommended replacing and/or repairing radiator traps and valves for individual apartments. "Each of the radiator traps, as well as the steam riser traps, should be checked or changed for proper operation," he advised.
Over a three-week period, the co-op followed these suggestions, revamping the heating controls. "Because of the piping configuration we were able to segregate it into four zones, giving us more control," recalls Fricke Jr. "We also examined the radiator traps and valves, which are often ignored. Many of them had worn out. We replaced most of them."
The result: less fuel burned and more energy saved. In another letter to Grogan, Sarubbi estimated that "the energy saved by balancing the heat levels can be as much as 10 to 12 percent of oil usage. If the building currently uses 250,000 gallons of oil per year at a cost of 75 cents a gallon, then the total energy cost is $187,500. A ten percent conservative savings would be $18,750 per year...[meaning] a payback within three years from the date of installation." |
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Excepts from an article in
Habitat Magazine — May 2003 – Number 190
by Michael Gwertzman
SAVINGS SOLUTIONS: TALES FROM THE TRENCHES
Controlling Steam
When things got too hot at the Gramercy, 301 East 22nd Street, residents knew how to cool their apartments off: open up the windows. However, this effective but inefficient method of temperature regulation was costing the 262-unit co-op big bucks in steam bills. Mel Hartman, former board president, and Steven Hirsch, managing agent at Goodstein Management, knew there had to be a better way to get the building's heating situation under control.
Leonard Powers, a steam analysis and maintenance company brought in to help save money, came up with a high-tech system that gives the building greater control over steam usage and energy efficiency. It was so successful, in fact, that Con Ed actually came by to investigate the building's marked drop in steam consumption.
The system modulates the building's heating valve by taking readings from a temperature sensor outside the building, 16 sensors installed inside apartments in the building (four apartments on four floors), and a sensor that measures the condensate temperature (the steam coming back from the apartments). A Baelz heat controller averages the readings and opens or closes the heating valve depending on the information.
Superintendent Bill Wiedemann can monitor the controller and make adjustments to the heating valve via his office computer. He can dial in from home, enabling him to respond quickly to residents' complaints on the weekend (before the new system was installed, the valve would have to be adjusted manually).
"The heating system needs to be viewed in its entirety," says Greg Fricke Jr., president of Leonard Powers. The building's mechanical operations - especially the vacuum pumps and heat traps - also have to be working correctly. "It's understanding how each component fits in and works together that allows us to achieve the kind of success we've had with these properties."
Fricke also meets with Wiedemann, Hartman, and Hirsch every quarter to go over the system's results and discuss any possible improvements. In addition to the computer readings, each building resident is surveyed during the heating season to determine the comfort level in his/her apartment. These surveys help determine where drafts might be coming from and try to trouble-shoot why some apartments have a greater variance in temperature.
The work first began over four years ago at the Gramercy, and has progressed in different stages. Fricke estimated that each phase of the work — the control panel and zone valve, the vacuum pumps, the new traps — cost anywhere from $10,000 to $20,000. But the co-op has cut down its steam consumption significantly, saving the co-op between 15 and 20 percent on its monthly steam bills.
Despite the rough winter New York has weathered, the residents at 301 East 22nd have been warm without wasting energy. "The steam usage is way down," Weidemann comments, "even though it's a lot colder." |
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Leonard Powers, Inc. • Steam Specialist • Mechanical Services • Valve Repair
519 West 27th Street, New York, NY 10001 • Phone (212) 244-8878 • Fax (212) 563-4761
Distributors for Spence Valves, Thrush Pumps, Leslie Controls, Ajax Boilers |
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