As multifamily buildings across the State consider converting to air source heat pumps (ASHPs), many will hesitate to do so because of the high construction cost and major tenant disruption associated with installing split systems. The need to penetrate the exterior walls to run refrigerant linesets and condensate drains, the additional cost of soffits for the interior lineset runs, the exterior space required for outdoor units, and the requirement of 208 VAC operation are just a few of the many barriers to conversion. Add to these the likely future shortage of capable HVAC technicians - and the potential for refrigerant leaks (and their corresponding GHG harm) - and the problem becomes almost impossible to address cost-effectively. While improved packaged terminal heat pump (PTHP) technology is promising for buildings with existing PTAC sleeves, many more buildings do not have this option and will face prohibitively high barriers to installing variable refrigerant flow (VRF) or split systems. A third option is needed to ensure that all buildings can afford a heat pump conversion. The Clean Heat for All (CH4A) initiative was initiated to compel manufacturers to design such a product - a PWHP that provides the efficiency of a cold-climate split-system in a single-package form factor to fit inside a large majority of apartment windows and operate on 115 VAC +/- 10%, single phase, 60 Hz. This would minimize the need for mechanical contractors with certifications for refrigerant management (such as “EPA 608”) and sharply reduce the high barriers to retrofit installations. Minimal new technology would be needed to develop such a unit - existing hardware could be re-packaged to achieve all design goals. Most importantly, the PWHP will deliver the benefits of heat pump electrification to tenants of affordable housing. The CH4A PWHP is a better insulated and less visually obtrusive replacement to window air conditioners that are prevalent in New York City and the northeast. CH4A is aimed at affordable housing is applicable in all types of buildings. Press release: https://www.nyserda.ny.gov/About/Newsroom/2022-Announcements/2022-08-02-Governor-Hochul-and-Mayor-Adams-Announce-Clean-Heat-for-All