New Heat Pumps And Multi-family Buildings

New York Energy Assessments
Sep 23
4 min read

Updated: Oct 6

<h1>New Heat Pumps Change Multi-family Landscape in NYC</h1>

<p class="lead">2024 Loring STHP Case Study — Fujitsu General America, Inc.</p>

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<h2 id="overview">Project Overview</h2>

<p>New York City has one of the highest concentrations of PTAC (packaged terminal air conditioner) units in the country. These units are widely used across hotels, hospitals, and multi-family residences. While PTACs are popular for their low upfront costs and ease of replacement, they can be noisy. They also allow for temperature swings and consume more energy than modern alternatives.</p>

<p>As the city advances its efficiency and decarbonization goals, Fujitsu’s <strong>Split Terminal Heat Pump (STHP)</strong> was piloted at the Loring Avenue Apartments in Brooklyn, NY. This system serves as a direct through-wall replacement for PTACs. This case study summarizes one year of measured performance and tenant/owner feedback.</p>

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<h3 id="facts">Quick Facts</h3>

<div><strong>Project</strong></div><div>Loring Avenue Apartment Complex — STHP</div>

<div><strong>Location</strong></div><div>Brooklyn, NY</div>

<div><strong>Comparison Window</strong></div><div>Dec 16, 2022 → Dec 16, 2023</div>

<div><strong>Installed STHPs</strong></div><div>113 units (36 in initial pilot)</div>

<div><strong>Capacities</strong></div><div>9,000 & 12,000 BTUh</div>

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<dt>Owner</dt><dd>Arker (The Arker Companies)</dd>

<dt>Project Developer</dt><dd>BlocPower</dd>

<dt>HVAC Engineer</dt><dd>MaGrann Associates</dd>

<dt>HVAC Contractor</dt><dd>Supercool HVAC LLC</dd>

<dt>HVAC Distributor</dt><dd>Johnstone Supply — West Michigan</dd>

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<p>The STHP is a through-wall split heat pump engineered as a direct PTAC replacement. A wall-mounted indoor unit, similar to Fujitsu’s mini-split line, pairs with a condenser placed inside the original PTAC sleeve. This design preserves the building’s façade and envelope opening.</p>

<li>Direct through-wall PTAC replacement (no major exterior changes)</li>

<li>Wall-mounted indoor unit + in-sleeve condenser</li>

<li>Available in 9k and 12k BTUh</li>

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<h2 id="methodology">Methodology & Data</h2>

<p>MaGrann Associates collected a full year of utility data from apartments at Loring Ave. equipped with STHPs and similar baseline apartments retaining gas PTACs. Apartments were grouped by size and location for comparability:</p>

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<li>Group 1: Ground-floor studios</li>

<li>Group 2: 1-bedroom ground-floor units</li>

<li>Group 3: 2-bedroom top-floor units</li>

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<p>Energy use was disaggregated by first determining a monthly baseload, which is the average of each apartment’s three lowest months. The remaining usage was then attributed to heating and cooling. Costs and emissions used the following factors from site bills and NYC Local Law 97 (2024):</p>

<ul>

<li><strong>Electricity rate:</strong> $0.25/kWh</li>

<li><strong>Gas rate:</strong> $1.29/therm</li>

<li><strong>Emissions factors:</strong> 0.29 kg CO₂/kWh (electric), 5.3 kg CO₂/therm (gas)</li>

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<span class="pill">Figure</span>

<p style="margin:10px 0 0">Annual heating & cooling electricity use ranged from ~350 to 2,500 kWh. STHP apartments averaged ~1,550 kWh, while baseline (gas PTAC) averaged ~1,179 kWh.</p>

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<figcaption id="fig1cap">Illustrative summary of measured electricity consumption distributions.</figcaption>

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<h2 id="results">Key Results (12-Month Window)</h2>

<h3 style="margin-top:0">Utility Cost</h3>

<p><strong>−26%</strong> average annual heating & cooling utility cost for STHP apartments vs. baseline (<em>~$133</em> lower on average).</p>

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<h3 style="margin-top:0">Emissions</h3>

<p><strong>−65%</strong> CO₂e for STHP apartments on average (≈ <em>−822 kg</em> CO₂e/apt annually).</p>

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<h3 style="margin-top:0">Electric Use</h3>

<p>STHP apartments averaged ~1,550 kWh for heating/cooling; baseline PTAC units averaged ~1,179 kWh.</p>

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<p class="muted" style="color:var(--muted)"><em>Note:</em> With the exception of emissions, preliminary results may be within the margin of error; expanded data collection and analysis continue.</p>

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<h2 id="install">Installation Approach</h2>

<p>The retrofit scope replaces each gas-fired PTAC with an STHP sleeve and condenser. It also runs line sets and mounts the indoor unit. According to Supercool HVAC, a two-technician crew typically completes <strong>one apartment per day</strong>.</p>

“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. It takes about one day per apartment with two technicians.” — <strong>Noel Cruz</strong>, Supercool HVAC LLC

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<h2 id="experience">Tenant & Owner Experience</h2>

<p>Property management reported fewer comfort complaints post-retrofit. The STHP’s indoor comfort benefits include more stable temperatures and much lower in-room noise. It has been cited as <strong>up to 87% quieter</strong> than typical PTACs. For owners, the STHP features a <strong>12-year parts warranty</strong> and an expected service life <strong>2–3× longer</strong> than standard PTACs.</p>

“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.” — <strong>Ilsoo Kim</strong>, Progressive Management (The Arker Companies)

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<h2 id="context">Context & Market Fit</h2>

<p>At introduction, the STHP was the only PTAC alternative efficient enough to qualify for NYC Clean Heat rebates and financing without moving to mini-splits or VRF. While higher-efficiency PTACs now exist, they generally retain PTAC-typical noise and comfort limitations. Given NYC’s vast PTAC installed base, STHP opens a practical electrification pathway.</p>

“The STHP is a fantastic solution for efficiency, carbon reduction, and landlord bottom line. This is the future for through-wall HVAC.” — <strong>Noel Cruz</strong>, Supercool HVAC LLC

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<h2 id="takeaways">Takeaways</h2>

<li>Measured <strong>−26%</strong> annual heating & cooling utility cost vs. gas PTAC baseline (≈ <strong>$133</strong> per apartment).</li>

<li><strong>−65%</strong> CO₂e emissions on average (≈ <strong>−822 kg</strong> CO₂e per apartment annually).</li>

<li>Direct through-wall PTAC replacement preserves façade; minimal disruption.</li>

<li>Quieter in occupied spaces (reported up to <strong>−87%</strong> noise).</li>

<li>Longer expected lifespan (≈ <strong>2–3×</strong> of PTAC) and <strong>12-year parts warranty</strong>.</li>

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<p class="callout">Compared to PTACs that use electricity for heating, STHP utility cost savings can approach <strong>~60%</strong>, depending on NYC heating degree days, STHP COP, and prevailing energy prices.</p>

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<h2 id="credits">Credits & Notes</h2>

<p><strong>Fujitsu General America, Inc.</strong> — AIRSTAGE® is a worldwide trademark of Fujitsu General Limited. Specifications/design subject to change without notice. Rev. 02/2025.</p>

<p>This case study summarizes preliminary results from a limited apartment sample at Loring Avenue (Brooklyn, NY). Ongoing monitoring aims to refine and confirm long-term performance.</p>

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<p>FUJITSU GENERAL AMERICA, INC. · <a href="https://www.fujitsugeneral.com/" target="_blank" rel="noopener">fujitsugeneral.com</a></p>

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