A co-op on the Upper East Side recently upgraded its heating and cooling system to a more efficient heat pump system, avoiding carbon emissions penalties and saving money in the process. (Print: A Waste Of Energy)
Michael Scorrano
Founder,
En-Power Group
“Any building that is centrally cooled and uses fossil fuel is a prime candidate for electrification”
Upgrading an inefficient heating and cooling system by going electric isn’t as simple as putting in new equipment. Switching mechanical systems often requires increasing a building’s electrical load capacity as well as navigating space constraints to meet safety regulations. Michael Scorrano, the managing director and founder of En-Power Group, recently worked through these challenges for a co-op on the Upper East Side.
Avoiding Penalties and Conserving Energy
Staring down Local Law 97 penalties of $80,000 for excess carbon emissions, the board at 525 E. 82nd St. needed to decide how to upgrade the building’s outdated heating and cooling system. In the summer, the gas-powered boiler was running a low-pressure absorption chiller for its air conditioning needs. “That setup uses fuel to make steam in the boiler, which is sent to the air conditioning equipment to help drive the refrigeration cycle to cool the building,” Scorrano explains. “It was very inefficient.”
Avoiding hefty penalties was important for the board, but wasting energy was also a concern. “It became evident that replacing the absorption chiller with heat-pump technology was the best approach,” he explains, adding that any building that is centrally cooled and continues to use fossil fuel is a prime candidate for electrification. Rather than burning fuel to create heat, heat pumps move heat energy from one place to another — from indoors to outdoors during the cooling season, and from outdoors to indoors during the heating season. Instead of a refrigerant solution in the pipes of each apartment’s individual air conditioners, the pumps circulate water chilled by the heat pumps.
The Challenge of Increasing the Building’s Electrical Load Capacity
Making the switch, however, required amping up the electrical load for the air conditioning units — literally. “What we find is that generally there’s at least enough capacity coming from the street into the building, which means the upgrade can take place,” Scorrano says. To increase the load inside a building, a request for service must first be made to Con Edison.
However, it can often be a challenge to meet adequate working space allowances, or safety clearances, that are mandated by the Department of Buildings. Installing a larger electrical capacity system at the co-op required more space than what was originally allocated in the 1960s-era building.
It also required the manufacture of customized switchgear, the centralized collection of circuit breakers and fuses. “After some back-and-forth with the manufacturer and discussions with the Department of Buildings, we were allowed to move forward with the design that was sufficient to meet the clearances,” Scorrano says. This allowed the team to increase the power in the building by 200 kilowatts. “Without that increase, we wouldn’t have anything that would power the equipment,” he adds.
Modular Heat Pumps Simplify the Installation
The six heat pumps, with a cooling capacity of 30 tons each, were installed in the building’s basement mechanical room. Their modular design allowed the building to avoid the cost of opening up a garage wall to install the new chiller equipment. “That would have been a much higher cost,” Scorrano says. “Instead, the modular pumps fit through the doorway, and you bolt them together in place in the room.” Even so, some modifications were needed inside the room to meet the required space clearances and safety regulations.
The Project Will Pay for Itself Within Five Years
The project cost was $900,000, which included the installation of new pumps with variable frequency drives. These allow for added flexibility to the system so pumps are not working at 100% all the time. “If you look at the $900,000 that the board invested, and if you take into account the future savings as well as the carbon penalty avoidance, this project should pay for itself in five years or so,” Scorrano says. The building no longer burns natural gas in the summertime for cooling, although natural gas will continue to be used throughout the year to heat the domestic hot water. “By putting in properly sized pumps with variable frequency drives and slightly reducing the operating speed of those pumps, we were definitely able to increase efficiency,” he says.