New Heat Pumps Change Multifamily Landscape in NYC

Much is left to be desired in a space conditioned with PTAC systems, however.  PTACs tend to create a great deal of noise within the occupied space, produce dramatic indoor temperature swings, and consume more energy than most modern HVAC system alternatives.

As New York rapidly seeks to improve the efficiency of its infrastructure, lower demand on its electrical grid, and reduce consumption of fossil fuels city-wide, many studies are being conducted to determine how best to apply private and public funds to that end.

One such study pertaining to PTACs and viable alternatives has been underway at a group of multi-family properties in Brooklyn since 2022. 

Site identification

An apartment building on Loring Ave. owned by The Arker Companies was selected for a retrofit pilot project and data analysis to compare the performance of PTACs against the new STHP (Split Terminal Heat Pump), made by Fujitsu General America. 

The STHP is a through-wall split system designed as a direct replacement for PTAC units.  The indoor unit, which is a wall-mounted type similar to those in Fujitsu’s mini-split product line, is paired with a condensing unit that mounts inside a wall sleeve occupying the original PTAC wall penetration.  Available in 9,000 and 12,000 BTUh capacities, the STHP can heat or cool any space that had previously been conditioned with a PTAC.

The project site was identified by MaGrann Associates, an energy efficiency and green building consulting and engineering firm.  MaGrann has worked with The Arker Companies on previous demonstration projects.  MaGrann, in partnership with Fujitsu, selected The Arker Companies site to conduct a performance comparison between the STHP heat pumps and the existing gas fired PTAC systems.  Jordan Dentz, VP and manager of building performance services, led the analysis. 

“MaGrann partnered with Fujitsu to prepare the project proposal and secure funding, developed the work plan and designs, and coordinated the project up until the units were installed,” explained Dentz.  “BlocPower, a national project developer, was brought in by The Arker Companies to manage the installations.”

BlocPower acts as a one-stop-shop for HVAC and clean energy upgrades, providing engineering design, incentive capture, financing, construction management and regulatory compliance.

“Once a site is identified, BlocPower provides a turnkey service to evaluate, finance, engineer, install, and commission projects,” said Ryan Merkin, VP of business development at BlocPower.  “We’ve completed more than 1,000 energy efficiency and electrification projects nationwide.”

Though the initial pilot project included 36 retrofits, 113 STHP systems have been installed at the Loring Ave. property to date.

“This work involved removing the gas-fired PTAC, installing the STHP wall sleeve, placing the condenser inside, running line-sets to the indoor unit, and hanging the evaporator,” explained Noel Cruz, owner of Supercool HVAC LLC.  “It takes about one day per apartment with two technicians.”

Supercool HVAC conducts roughly a dozen heat pump retrofit projects as a subcontractor for BlocPower each year.   

“This retrofit project is congruent with The Arker Companies’ goals to reduce energy and fossil fuel consumption while increasing tenant comfort,” said Ilsoo Kim, facility manager for Progressive Management, the management arm of The Arker Companies.  “In my line of business, the lack of comfort complaints is the greatest sign of success, and that’s exactly what we’ve experienced from the units that have been retrofitted.”

Initial Energy Improvements

To conduct the preliminary data analysis, one full year of utility data was collected from a sample of apartments to evaluate energy, cost, and emissions of the newly installed Fujitsu STHP systems compared to existing gas fired PTACs.

MaGrann collected electricity and gas meter readings monthly for a selection of apartments at Loring Ave. served by STHPs and similar baseline apartments with the existing gas PTACs. The apartments were split into groups by size and location:

• Group 1: ground floor studios
• Group 2: 1-bedroom ground floor units
• Group 3: 2-bedroom top floor units

Each group has at least one full year of occupied data. Electricity, gas use and costs and emissions were compared within the same group. All data was from the same time period: from Dec. 16, 2022 to Dec. 16, 2023.

Natural gas is used for cooking in all apartments and, in the baseline apartments, for space heating. In the baseline apartments, electricity is used by the PTAC compressor in cooling mode and blower in heating and cooling mode, and other miscellaneous, plug and lighting loads.  In the STHP apartments, electricity is used for all heating and cooling as well as miscellaneous, plug and lighting loads.