New York City Large Multi-Family Residential Heat Pumps

New York’s Climate Leadership and Community Protection Act (Climate Act) has been the primary focus of this blog since 2019.  I am from Upstate New York so I really have not been following New York City’s equivalent regulation Local Law 97.  This article looks at what it would take to meet the requirement that law’s requirement that “most buildings over 25,000 square feet will be required to meet new energy efficiency and greenhouse gas emissions limits by 2024, with stricter limits coming into effect in 2030”.

Everyone wants to do right by the environment to the extent that they can afford to and not be unduly burdened by the effects of environmental policies.  I submitted comments on the Climate Act implementation plan and have written extensively on New York’s net-zero transition because I believe the ambitions for a zero-emissions economy embodied in the Climate Act outstrip available renewable technology such that this supposed cure will be worse than the disease.  Moreover, many of the implementation requirements are going to increase costs tremendously.  The opinions expressed in this post do not reflect the position of any of my previous employers or any other company I have been associated with, these comments are mine alone.


Both the Climate Act and Local Law 97 are intended to meet a “Net Zero” target (85% reduction and 15% offset of emissions) by 2050.  Since 2020 the Climate Action Council has been working to develop plans to implement the Climate Act.  Over the summer of 2021 the New York State Energy Research & Development Authority (NYSERDA) and its consultant Energy + Environmental Economics (E3) prepared an Integration Analysis to “estimate the economy-wide benefits, costs, and greenhouse gas (GHG) emissions reductions associated with pathways that achieve the Climate Act GHG emission limits and carbon neutrality goal”.  Integration Analysis implementation strategies were incorporated into the Draft Scoping Plan when it was released at the end of 2021 for public comment.  The next step is to finalize a scoping plan by the end of the year.  Incredibly the proposed transition plan does not include sufficient feasibility analysis to determine whether it will be affordable, reliable, or what the cumulative environmental impacts will be on the state.

I have intended to write an article since I read an article describing “cutting-edge” climate technology for New York City public housing.  That article describes the first awards of the Clean Heat for All Challenge that I described in an earlier post.  The New York City Housing Authority (NYCHA), New York Power Authority (NYPA) and New York State Energy Research and Development Authority (NYSERDA) launched the Clean Heat for All Challenge as “an industry competition directed at heating and cooling equipment manufacturers to develop a new electrification product that can better serve the needs of existing multifamily buildings and hasten the transition to fossil-free heating sources.  While this challenge is laudable the fact is that the Climate Action Council presumes it will be successful and has not established standards for affordability and reliability.  If a reliable system doubles the cost of housing is that acceptable?  If an affordable system risks frequent and severe blackouts is that acceptable?  New York’s approach is to cross their fingers and hope that these implementation schemes will work.

Integration Analysis Residential Heating Costs

Because GHG emissions from buildings is the largest remaining sector in the State, the Integration Analysis proposes to replace all fossil-fired generation with electric options.  As part of my comments on the Draft Scoping Plan I consolidated all the residential heating information in the Integration Analysis in a single spreadsheet.  The Integration Analysis supporting documentation included device costs for Single-Family, Small Multi-Family, and Large Multi-Family residences.  The Bldg Device Cost tab lists all the costs.  A complete table with current building shell, air conditioning, hot water, and heating costs for Large Multi-Family residences is available.  The following table consolidates device costs for three choices of building shells, air source heat pumps, backup electric resistance heat, and electric heat pump storage that I believe represents the costs to replace heating and hot water from the steam boiler systems used in many New York City Large Muti-Family apartment buildings.  There is not enough documentation for me to definitively state that these represent the Integration Analysis best estimate of likely expected costs so I made the following assumptions.  Anecdotally my son’s Brooklyn apartment had air source heat pumps that were inadequate in the winter because the building shell had not been upgraded so I think a basic shell upgrade is appropriate.  I think the costs should include a basic shell upgrade ($26,259), an air source heat pump ($26,873), electric resistance heating because the basic shell is insufficient in the coldest weather (($1,140) and an electric heat pump water heater ($3,267) to provide hot water for a grand total of $57,539.

NYCHA Woodside

Environmental Justice advocates have repeatedly complained that disadvantaged communities have problems heating their homes.  The poster child of New York City Housing Authority (NYCHA) developments with heating problems is the Woodside Development in Queens.  After Hurricane Ida damaged the heating boilers in August 2021, Queens lawmakers toured the facility after resident complaints about problems with heat and hot water in January 2022.  The problems are still not resolved because in early October 2022 residents still were having problems. 

According to MYNYCHA “Woodside Houses has twenty, 6-story buildings and was completed December 30, 1949.  The Heating Action Plan states that there are 20 buildings with 1,357 apartments for 2,842 residents.  The heating system has six boilers that provide heat and hot water through a two-pipe steam system.  The plan’s “major challenges” states:

This plant needs to allow all six boilers to individually switch to fuel oil during a gas service disruption. The current setup only allows staff to switch all boilers to either gas or oil. These are old models of the Preferred brand burners which cause difficulty in obtaining parts during an emergency. The boilers at this location have outlived their life expectancies.

The “cutting-edge” climate technology article interviewed Woodside residents in its article about window heat pumps.  The article stated:

In an effort to help public housing residents stay cool in the summer and warm in the winter without resorting to extreme and even dangerous measures, New York announced the winners of its Clean Heat for All Challenge on Tuesday. It awarded $70 million to Gradient and Midea America, a startup and an established HVAC company, respectively. The duo will use that funding to manufacture 30,000 window heat pump units over seven years.

While the technology is relatively new and unproven at scale, proponents of the window heat pump say it could address a number of problems that plague New York’s public housing, which one in 16 New Yorkers call home. Many of those buildings feature outdated and unreliable heating systems as well as poor insulation. A large number of residents also lack access to air conditioning due to the cost of buying window units and the fees for professional installation and added energy use required by the New York City Housing Authority.

The Clean Heat for All Challenge description states:

The challenge calls upon manufacturers to develop a packaged cold climate heat pump that can be installed through an existing window opening to provide heating and cooling on a room-by-room basis. The envisioned product would enable rapid, low-cost electrification of multifamily buildings by reducing or eliminating many of the cost drivers inherent to existing heat pump technologies when used in resident occupied apartments. These include costly electrical upgrades, long refrigerant pipe runs, drilling through walls and floors and other construction aspects which result in high project costs, and significant disruption to residents.

In my post on the Clean Heat for All Challenge I described another NYCHA electrification project where they are testing a Variable Flow Refrigerant heat pump system that I showed was very expensive likely due to the disadvantages of existing heat pumps described in the previous paragraph.  Of the 30,000 window heat pumps NYCHA plans to purchase in the coming years, 10,000 will come from Gradient and 20,000 from Midea. If the project is a success, it could provide a more financially viable alternative.  However, there are very few cost details available. 

The Draft Scoping Plan does not do a very good job explaining that many of the control technology options used in the Integration Analysis are on the cutting edge of technology.  In many cases, the required technologies have not been applied at scale so it is possible that there will be unforeseen issues that either increase costs or threaten the viability of the technology.  Gradient is a San Francisco based startup with a clever window sited heat pump.  Although Midea is an established HVAC company the heat pump offerings on its web site are sparse. The only Midea America heat pump  option that I found that might be appropriate is the Thermal Arctic Series ATW Heat Pump, MHA-V16W/D2RN8-B, HB-A160/CGN8-B, HBT-A160/240CD30GN8-B.  The description states:

Discover the real peace of mind for you right being at home. The eco-friendly, low-noise M Thermal Arctic Series Air-to-Water Heat Pump integrates air heating, cooling, floor heating and domestic hot water into one system, which is specially designed for satisfying all your demands. With the Built-in hydraulic kit and integrated design, the Mono type M Thermal is highly friendly for household installation. High efficiency and wide operating range allows proper selections under numerous utilization conditions according to the actual needs. Intelligent control and flexible maintenance bring convenience both to users and service providers.

The NYCHA Woodside boilers provide heat and hot water.  The Midea option appears to address both needs but it is not clear if the Gradient unit does.  In order to provide hot water plumbing to the water system will have to be installed and that raises questions about the applicability of any window unit.

There is another aspect of the heating application that was glossed over in the Draft Scoping Plan and rarely gets mentioned by heat pump advocates.  For example, consider the following picture from the Gradient website.  In order for heat pump technology to maintain comfortable temperatures when temperatures drop below 20o F the building shell has to be upgraded or resistance heating has to be used.  The efficiency of heat pumps is a great benefit but the inefficiency of resistance heating is a big disadvantage that will likely require upgrades to the distribution service to the housing complex.  In this picture the window is going to have to be replaced with a more energy efficient type and the wall itself would have to be insulated in order for a heat pump to provide all the heat necessary in that room.

Gradient Website Home Page

The press releases do not address total transition conversion costs.  Assuming that the NYCHA housing does not have insulated walls then there is a major problem.  The only ways to provide additional insulation is to add rigid foam insulation over the existing wall or frame a wall next to the existing wall.  In a high rise the only practical way to do this is to add those options on the inside.  As noted previously I believe that in order for a comfortable solution the building shell has to be upgraded to a basic shell.   The unit costs for the window heat pumps are cheaper than the Integration Analysis device costs but it is not clear how many window heat pumps per apartment are needed, whether building shell upgrades will be included in the transition, if backup resistance heat is included and what will provide hot water.

Private Condominium Example

Nearly half of the residences in New York City are in high rise multifamily buildings and on the order of 30% of those are in NYCHA projects. Writing at the Manhattan Contrarian website Jane Menton described the impact of Local Law 97 on her condominium that is representative of the rest. In her article she describes an email sent to the condominium board that said:

“I just wanted to bring this topic to your attention… The Climate Mobilization Act of 2019 will have a big impact on our building. Our emissions must be cut by 60% in the next 10 years or so. If we fail, the fines are in the range of $150k a year. We will be required to make hundreds of thousands of dollars in investments to upgrade our systems.”

She went on to describe the details for her building:

My colleague’s email was accompanied by the following chart, created by this website, called the NYC LL97 Carbon Emissions Calculator. This site has been endorsed by the City for buildings to use to calculate how much they are supposed to reduce their carbon emissions and how much they will owe in fines if they fail to install “zero-emissions” heating systems by the set deadlines. Here is the chart that my colleague came up with for our building:

According to the chart, about 75% of our carbon emissions result from our natural gas heat, represented in green in the circles in the lower right portion of the chart.  The City’s statute mandates a series of lowering thresholds for building emission per square foot of space. By 2035, supposedly we must reduce our emissions by 60%, or face fines well in excess of $100,000 per year. In order to reduce our emissions by 60% we would have no option but to convert our building away from its current gas heat system – which is quite reliable, only a few years old, and in fine working condition – to an electric heating system.  

Menton’s board has not estimated the costs to electrify their heating system.  She explains:

Assuming that they decide to or are forced to go along with this, how much will it cost the unfortunate co-op owners? We haven’t yet had an estimate done for our building, but here are a few words from Warren Schreiber, board president of another Queens co-op, the Bay Terrace Gardens Co-op Section 1, and co-president of the Presidents Co-op & Condo Council (PCCC):

Converting to (electric) heat pumps will cost [the co-op] $2.5 to $3 million, which does not include finance charges. This expense will result in a 25-30% monthly maintenance increase. Shareholders who have lived here for 20, 30, 40 and 50 years will have to leave Bay Terrace Gardens to find more affordable housing.

Sadly, I would not be surprised that the heat pump conversion price shown does not include the costs for upgrading the building shell, providing hot water, and backup heat.  I do not know how Local Law 97 addresses the inability of heat pumps to provide sufficient heat at temperatures below 20o F.  Given that the costs will likely double I cannot imagine a scenario where building owners will bother to upgrade building shells.  Most likely it won’t be considered until electrified buildings all over New York City start tripping their breakers or, worse, the combined load of all the electrified buildings causes sub-stations to trip off line plunging sections of New York City into blackouts.  Importantly this also means that the Integration Analysis expectations for New York City peak wintertime loads that assume building shell upgrades underestimate likely future loads.


I have written over 250 articles about the Climate Act and the implementation plans.  In my opinion the biggest single shortcoming of the whole boondoggle is the lack of a feasibility plan addressing affordability and reliability feasibility.  The Integration Analysis depends on technology that has not been deployed at the scale necessary nor in differing applications necessary for the residential heating electrification.  Fortunately, in this sector the heat pump technology proposed for electrification has a long commercial history. The issue is how effective they will be at low temperatures when there simply isn’t enough energy in the air to keep residences warm in large multifamily buildings without substantive building shell upgrades.  While there are potential solutions the costs and implementation issues are speculative.  The Draft Scoping Plan provides undocumented device costs and the total costs relative to an arbitrary reference case but no breakdown of likely implementation costs per sector. 

The specifics on affordability and reliability should give planners concern.  The Integration Analysis all-in device costs including the “Basic” building shell upgrades for large multifamily residences total $57,539 per residence.  The Integration Analysis states that there are 1,667,493 high rise multifamily residences in New York City alone.  On the face of it that works out to nearly $96 billion for the net-zero transition.  That is just affordability feasability.  When 1.7 million New Yorkers have to turn on their backup resistance heaters it will create a peak load substantially higher than the current peak load.  I believe that will require upgrades to the electric distribution system which if unaddressed will lead to reliability issues.  In addition to this cost, it introduces an unprecedented stress to the electric grid.  While I hope that the electric system planners will anticipate all the potential problems and upgrade the grid accordingly, the inclusion of a large percentage of generating resources that are intermittent and unable to be dispatched on demand makes me very pessimistic that there will not be learning curve blackouts.


In every instance where I have evaluated a component of the New York energy system and the challenge of a net-zero transition I have found that the problems are more complicated and uncertain than presumed in the Integration Analysis and the Draft Scoping Plan.  As a result, I think the costs are underestimated and the potential risks to reliability a significant risk.  The challenge of meeting Local Law 97 is no different.  It is very easy to promulgate an aspirational target but clearly the politicians involved have no clue about the scale of the challenge.  If they did, they would not be so anxious to jump into these laws.  I have shown that New York’s total greenhouse gas emissions are less than one half of one percent of total global emissions and that since 1990 global emissions have increased on average more than one half of one percent per year.  It is not clear what the point of these costs and these risks are when anything the state does is subsumed by what others are doing in a year. 

Author: rogercaiazza

I am a meteorologist (BS and MS degrees), was certified as a consulting meteorologist and have worked in the air quality industry for over 40 years. I author two blogs. Environmental staff in any industry have to be pragmatic balancing risks and benefits and ( reflects that outlook. The second blog addresses the New York State Reforming the Energy Vision initiative ( Any of my comments on the web or posts on my blogs are my opinion only. In no way do they reflect the position of any of my past employers or any company I was associated with.

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