Cooling Off, Cutting Costs

A Manhattan co-op leads the way in an innovative program to control spiraling air conditioning and energy bills.

It was a long hot summer, but one Manhattan co-op is ready, willing, and able to face many more. Jefferson Towers, a 20-story, 190-unit Mitchell-Lama co-op on the Upper West Side, has just finished installing a revolutionary air-conditioning system that could serve as an energy- and money-saving model for buildings throughout the city and, indeed, for cities around the world.

“Our goal is to voluntarily reduce our electricity usage during peak-demand times,” says Jordan Dentz, an architect with Levy Partnership who has lived in the building for all but two of his forty-two years. Dentz served on the co-op’s board from 2000 to 2003, when the building switched from master-metering to electrical submetering.

Under submetering, each unit has its own electric meter and pays only for the electricity it uses, instead of paying a fixed share of the whole building’s electric bill. The system, which can result in energy savings of up to 25 percent, proved to be a crucial building block for Jefferson Towers’s new air-conditioning system.

Last year, Dentz, who no longer sits on the Jefferson Towers board, placed a call to Herbert Hirschfeld, the engineer who served as a consultant during the successful switch to electrical submetering. During that conversation, Hirschfeld mentioned to Dentz that he was working on a project to install centrally controlled air conditioners using the electric submeters’ controls at the sprawling Georgetown Mews co-op in Forest Hills, Queens (see box, below).

“You can use the submetering system’s wireless communication technology to monitor other equipment in the building,” Hirschfeld explains. “Inside most air conditioners today is a module that’s compatible with a remote control. At Georgetown Mews, we’re taking out that control module and replacing it with one that’s compatible with the equipment installed by the company that did the electric submetering. Now, management can issue commands for individual apartments or for all the apartments that have these air conditioners.”

In addition, the apartments that are connected to the centralized air-conditioning controls have a color-coded light-emitting diode (LED) display that informs consumers which “time-of-use” electrical rate they fall under. During peak times, when rates are highest, a red light is on; during mid-level “shoulder” times, a yellow light is on; and during low-rate off-peak hours, a green light is on. Hirschfeld notes that the colored lights deliver a “subliminal message” to energy consumers.

Aware that the New York State Energy Research and Development Authority (NYSERDA) helps finance innovative energy-conservation projects, Hirschfeld and Dentz put together a proposal for Jefferson Towers that won a promise of funding from NYSERDA.

“It’s a research and development project,” says Tony Abate, an associate project manager with NYSERDA. “What’s innovative about this project is seeing if we can turn what was originally a master-metered building into a smart building.”

The next step was to approach the Jefferson Towers board and sell them on the idea that the entire co-op would benefit from the program in three ways. First, the new air conditioners would be more efficient. Second, the LED display would make shareholders more aware of fluctuations in electric rates and thus more likely to cut use during peak hours. And third, if it could cut its electricity use during high-demand “event days,” the co-op would win cash rewards from Con Ed and the New York Independent System Operator. The incentives are part of the Emergency Demand Response Program instituted in 2002 to reduce the risk of a blackout. New Yorkers who remember the blackout of 2003 are aware that the program is not fail-safe.

“The board was thrilled,” Dentz says, “because we were proposing that NYSERDA would subsidize the cost of the air conditioners and the building as a whole would save.”

One potential stumbling block was that management – the board and the super – would have some control over the temperatures in apartments, and those temperatures would tend to be slightly higher during the hottest hours of the day and on the hottest days of the year.

“But it wasn’t as hard as I thought it would be to get people to accept that,” Dentz says. “I was able to demonstrate that shareholders probably wouldn’t notice the difference in temperature. If I was an outsider who came in and tried to do this, they might have been more skeptical.”

During the summer, the co-op replaced 233 of the building’s 350 through-the-wall air conditioners with new retrofitted Fedders units. Shareholders paid just $100 for a bedroom A/C unit and $50 for a living room A/C unit. The total cost to shareholders for air conditioners and installation was $47,000. NYSERDA picked up $105,000 in expenses.

One requirement attached to the NYSERDA money is that the co-op must now gather data on the new system’s efficiency, which will take place during next year’s cooling season. “The proof will be in the numbers,” says NYSERDA’s Abate. “Do people and buildings save money? Do the benefits work environmentally and economically? During heat waves we’ve seen that there’s real value in being able to curtail loads. That’s commonly accepted. We think this project is taking conservation to the next step.”

Dentz agrees. “In areas where peak-demand is critical, such as New York City, this is a very effective way of controlling it,” he says. “One thing that would help this take off would be if manufacturers would install the technology in the factory. That might make it cost-effective even without subsidies. Then it would be a no-brainer, especially in new buildings.”

==HABITAT SIDEBAR==

News from the Mews:
Submetering Update

Rising energy costs are cutting into everyone’s bottom line, whether that is a co-op, condo, or private home. Georgetown Mews, a 37-building, 930-unit co-op in Queens, shows how a submetering system can cut energy costs by nearly 20 percent.

The cooperative complex was facing increasing energy costs, so its board decided to take action (see “Behavior Modification,” Habitat, July/August 2008). Each unit-owner already paid a set electricity fee, based on the number of shares they owned as opposed to the amount of energy consumed.

Led by its president, Mary Fisher, the board wanted to redistribute the complex’s energy costs to reflect actual usuage. The co-op is a master-metered complex, with 33 utility master-meters that record the energy usage in all 930 apartments.

Before submetering, the shareholders’ utility costs were based on readings of these master-meters as part of their monthly maintenance charges. The 137 rent stabilized apartments’ electric charges were included in their rents as determined by DHCR guidelines. With the implementation of the new submetering system, the board continues to pay Con Ed based on the master-meters and still maintains the 25% discounted bulk rate, but in turn bills the shareholders according to their individual usuage during peak or off-peak times of the day.

The impact of the individual submeters is quickly apparent. If a shareholder is surprised by her bill one month, she can adjust her behavior the following month by running high-energy appliances during off-peak hours – as displayed on the individual submeter in her apartment. Doing so also shifts building demand to off-peak hours which assists Con Ed in keeping the power on.

Initially, the projected annual reduction in energy usage and demand was 20%. Analysis of collected data for the past year shows that Georgetown Mews has met its goal. “Annual electrical usage reduction was 19.6%,” says Herbert Hirschfeld, P.E. who oversaw the project. “Demand reduction was 24.7%. The average benefit for each apartment exceeded $25 per month with an additional average benefit to consumers who shifted to off-peak hours of over two dollars per month. Those residents who aggresssively shifted usage to off-peak hours benefited up to an additional $15 per month”

These impressive numbers are due solely to the efforts of 793 apartments that are occupied by shareholders and not the 137 rent stabilized units, which continue not pay for their usage. The co-op pays the electricitic bills for these units, a decision which was made to avoid a lengthy DHCR approval process. Specifically, comparing the monthly bills of rentals with the shareholder occupied apartments showed that the rental apartments “consumed 30 to 50 percent more electricity per billing period than the shareholder occupied apartments.”

What this means is that while the participating residents of Georgetown Mews did successfully cut energy costs drastically, the overall savings could have been up to 15 percent better with those 137 apartments participating in the submetering process. This project certainly makes the case for submetering. – Kathryn Farrell

Edited by Herbert E. Hirschfeld, P. E.