CASE STUDY – COMMERCIAL OFFICE COOPERATIVE

IGP provided Owner’s Representative, Project Management and Financial Advisory services to assist the Owner in selecting the LL87/09 energy auditing team and the LL87/09 Retro-commissioning team to “comply early” in 2013. IGP also assisted the Owner of this historic Fifth Avenue commercial cooperative to access funding from NYSERDA’s Flex Tech Program to fund some of the retro-commissioning costs. IGP also does the LL84 Benchmarking every year.

IGP researched the history of the building and brought in an historical steam heating expert who determined that the building had a unique turn-of-the-century two-pipe/air vent heating system that was installed before the steam trap for buildings was invented in 1905. The proper energy efficiency measure was to replace the air vents, not add steam traps.

Source: 2-Pipe Air Vent System; Radford’s Cyclopedia of Construction by William A. Radford (1909)

Building’s Steam Heating History:

This building was built in stages from 1900 to 1909. In 1900 it was a ten-story building. The eleventh story was added in 1905 and two more floors were added in 1909.  Floors 1-11 have a two-pipe steam system and floors 12-13 have a one-pipe steam system. Between 1905 and 1930 more than two dozen completely different types of steam systems were invented.

The first successful “one-pipe” steam radiator was invented in 1854 by a New Englander named Stephen Gold. Steam and condensate shared the same radiator connection, so it was problematic from the start. Providing a second pipe was the beginning of what is called a “two-pipe/air vent” steam system which operates as a “one-pipe” system in that both the supply and return lines have steam and condensate traveling in opposite directions. This office building has this hybrid system, as do several other old buildings in New York City.

Air vents weren’t very sophisticated in those days so steam in both the supply and return lines moved toward the open air vents, which tended to spit water all over curtains and walls. With the invention of the thermostatic radiator trap in 1905, the two-pipe/air vent system passed into heating history (although like this building, there are still many in operation today).

Property Information:

• Market Type: Commercial Office Cooperative. This is a historic landmark building in the Union Square area of NYC.
• Building Area: 108,445 square feet
• Total Units: 13: 11 commercial; 2 retail
• Built: 1901 to 1909
• Original Heating Fuel: No. 6 oil. Converted to Natural Gas
• Projects: LL84/09, LL87/09 including extensive historical research of the heating system
• Incentive Program Approved: NYSERDA FlexTech Program to determine the appropriate LL87 Retro-commissioning recommendations for this unique heating distribution system.