Existing programs tend to focus on getting residents to upgrade their window units to newer, more efficient coolers. It is estimated that switching from a cooler that was built in the 1970s to a modern ENERGY STAR unit may save as much as $90-$100 a year. But a modern cooler only needs to use ten percent less energy to get the ENERGY STAR designation. While this successful program does provide some savings, it is a poor second best when compared to mini-split systems.

Most people are familiar with standard split system air conditioners. An air handler is mounted in a closet and circulates air through a duct system and a condensing unit is located outside of the building. Refrigerant is circulated between the units through copper tubing. A mini-split system is similar, except that it is much smaller. The indoor units are as small as twenty pounds and can be mounted directly to an external wall. The external unit, usually weighing around a hundred and fifty pounds or so, can located on the roof, on a patio or balcony, or, sometimes, mounted vertically on a wall.

There are many benefits to using a mini-split system over a traditional window unit. First, since the wall penetrations for the mini-split are permanent, they can be insulated so air leaks are minimized. Most window units are installed temporarily with little or no insulation installed around the seams. Keeping cool air in and warm air out provides an immediate savings. Second, a two-ton 16 SEER mini-split uses about about a quarter less as a 10 EER window unit of the same size. Third, window units are often installed at or below waist-level, which means that hot air stratifies and sits on top of cooler air near the surface. Fans must be used to circulate air to get more even cooling. With mini-splits, the air blower can be installed near the top of the wall so that cooler air naturally spreads through the living space. Additionally, for window units, if it is desired to cool additional rooms, additional units must be purchased and run at full power. Mini-splits offer the ability to run more than one blower from the same condenser. With variable speed compressers offered on many units, multiple rooms can be cooled with less energy than it would take to run one window unit at full power.

The drawback, of course, is the cost. A window unit can be purchased for under a hundred dollars and sat in a window by anyone strong enough to carry it. A mini-split requires professional installation and must be purchased through a heating and cooling contractor. Normally, when a superior product is pushed to the side by an inferior product, it is referred to as a market failure, and one of the legitimate functions of government is to regulate, and sometimes correct, market failures.

A grant program, offered through power companies and HVAC contractors, could bring the cost of such system down to the reach of most consumers. Even a zero-interest loan program paid for through a small monthly assessment on the power bill could be effective in moving hundreds of thousands of households to more energy efficient lifestyles. Since the estimated lifespan of a minisplit is more than triple that of an average window unit, it would also mean fewer air conditioners sitting in landfills and leaking their refrigerant into the air we breathe.

Such programs should not be considered instead of the Mayor's move to modern generation methods, but they should be considered a vital part of upgrading and modernizing our electrical use. It does little good to erect a wind turbine on a bridge if fifty window units are going to squander that green energy through air leaks and inefficient cooling systems. It won't be cheap, but it will be worth it in the long run.