**3. Today's best solution**

*Steam heating conversion into hot water heating (HWH)* is considered the best approach for today. The take-away from the 2010 successful steam to HWH retrofit project on a twelve story building at 179 Henry str., NYC were summarized as follows: "Over the years, many of us in the New York City multifamily energy efficiency world have talked about how cool it would be to convert steam-heated buildings to hydronic heating. The problem is not one of will but one of money. Changing the boiler is not the big deal—it's the heating distribution system that is the challenge. … Plenty of these conversions have been done in the last 20 years in buildings that were gut rehabs. These jobs did not always get the best boilers, or insulation in the walls, but they did get a more efficient heating distribution. The real challenge was to convert a building with steam heat, with tenants in place" [15]. The project required boiler replacement, core drilling the concrete deck floors (12 in all), running and enclosing the new piping and the heating elements. Fuel savings were 33%.
