When Brooklyn Buildings Can’t Beat the Heat: How 2024’s Scorching Temperatures Exposed the Dangerous Reality of Undersized AC Systems

The summer of 2024 will be remembered as a turning point for Brooklyn building owners and residents. New York City experienced a five-day heat wave with temperatures above 90 degrees, the first time the city hadn’t experienced five consecutive days above 90 degrees since June 1988. Through July 17, there were more 90-degree days in 2024 than the last two years combined, with three heat waves to-date, which is more than any of the last several years.

This unprecedented heat exposed a critical flaw in Brooklyn’s building infrastructure: cooling systems that were never designed to handle such extreme conditions. Undersizing can result in over reliance on backup heat, or inadequate summer cooling and increase energy costs, while uneven temperatures between offices, retail floors, or tenant areas often signal an undersized or outdated system.

The Science Behind Cooling Load Calculations

Understanding why so many Brooklyn buildings struggled during 2024’s heat waves requires examining the fundamentals of cooling load calculations. A load calculation is a method of determining the heat gain and loss of a home or building so that HVAC equipment is properly sized. It represents the amount of heating or cooling capacity that is needed during the coldest or hottest day of an average year to keep the interior of the space comfortable.

The problem is that many Brooklyn buildings were designed using historical weather data that no longer reflects current climate realities. The heat gain or heat loss through a building depends on the temperature difference between outside temperature and our desired temperature, and the type of construction and the amount of insulation in your ceiling and walls. When outdoor temperatures soar beyond design parameters, even properly sized systems can struggle.

2024’s Record-Breaking Heat Wave Impact

The heat waves of 2024 weren’t just uncomfortable—they were dangerous. On July 8, the Third Avenue Bridge stopped working and was closed down due to the heat; temperatures in New York City that day were 95°F. Temperatures were predicted to reach as high as 95 degrees Fahrenheit by Wednesday, June 19, and could climb as high as 101 degrees Fahrenheit throughout the next few days. New York City defines extreme heat events as periods when the heat index is 100 degrees Fahrenheit or higher for one or more days, or 95 degrees Fahrenheit or higher for two or more consecutive days.

The urban heat island effect made conditions even worse in Brooklyn’s dense neighborhoods. The findings reveal significant discrepancies in both the average and peak cooling demand when UHI effects are ignored, especially during nighttime. The most intense UHI effect was observed in LCZ 2.1, characterized by compact mid-rise and high-rise buildings, leading to a cooling demand increase of more than 20% compared to suburban data.

The Consequences of Undersized Systems

When cooling systems are undersized for extreme heat conditions, the consequences extend far beyond discomfort. On average, more than 500 people die prematurely in New York City each summer due to extreme heat, and the most common place of death was homes without air conditioning. A majority of city residents have air conditioners in their homes—around 90 percent according to city data from 2023. But not everyone can afford to run them all the time, increasing the chances of heat-stress and even heat-related mortality, especially for older residents and people with cardiovascular issues or other underlying conditions.

Building owners face mounting pressure as well. Outdated or undersized cooling systems can strain daily operations and drive up energy costs. In Brooklyn’s dense commercial buildings, outdated equipment often struggles with load demands, efficiency standards, and code requirements. Scheduling a reliable air conditioning installation early helps avoid disruptions, rising energy costs, and unexpected system failures.

The Technical Challenge of Proper Sizing

Many building owners rely on outdated “rules of thumb” rather than proper load calculations, leading to chronic undersizing. Professional Manual J calculations account for dozens of variables that simplified “rules of thumb” miss, and are increasingly required by building codes and equipment manufacturers for warranty compliance in 2025. Oversized systems waste 15-30% more energy through short-cycling, create humidity problems, and actually reduce comfort while increasing utility bills despite having “efficient” equipment ratings.

An undersized unit won’t cool effectively, while an oversized one will cycle on and off inefficiently. The challenge for Brooklyn buildings is finding the sweet spot that accounts for both normal operating conditions and extreme weather events that are becoming increasingly common.

Professional Solutions for Brooklyn Buildings

When Brooklyn building owners face cooling system failures or inadequate performance, professional expertise becomes essential. Companies like Lion-Aire understand the unique challenges of New York’s building infrastructure. Lion Enterprises is the proud parent company of three leaders in the PTAC market: Accumtemp, Lion-Aire and Spectrum. Together, our business units specialize in the service, repair and replacement of PTAC units and thru-wall equipment.

Located in Long Island City, Lion Enterprises specializes in the supply, installation, and servicing of Packaged Terminal Air Conditioning (PTAC) units, aiming to be the preferred partner for both residential and commercial clients. The company offers a range of services including PTAC repair, cleaning, and installation, supported by a team of highly-skilled technicians dedicated to exceptional customer service. With a commitment to exceeding environmental standards, Lion Enterprises guarantees all their work for one year.

What sets professional services apart is their understanding that they value the result more than the money. When cooling systems fail during extreme heat events, rapid response becomes critical. Since problems with a PTAC unit can happen at any time of the day or night and repairs often can’t wait, we offer rapid response repair and installation services. Our technicians are on-call 24 hours a day, 7 days a week, 365 days a year, and are always ready to come to the rescue.

Looking Forward: Adapting to Climate Reality

The heat waves of 2024 serve as a wake-up call for Brooklyn building owners. According to NPCC projections, New York City can expect, on average, up to 15 to 56 additional days where temperatures reach 90°F or above by the 2050s, and up to 24 to 75 additional days at 90°F or above by the 2080s. This means cooling load calculations based on historical data will become increasingly inadequate.

Building owners must now consider not just current cooling needs, but future climate projections when sizing systems. Professional air conditioning repair brooklyn ny services become essential partners in this adaptation, providing both immediate solutions for system failures and long-term planning for climate resilience.

The summer of 2024 proved that undersized cooling systems aren’t just an inconvenience—they’re a public health risk. As Brooklyn continues to face increasingly extreme heat events, proper cooling load calculations and professional system sizing will be essential for protecting both building occupants and property values. The time for reactive approaches has passed; proactive planning and professional expertise are now necessities in our changing climate.