Wallace Kirkman Harrison (September 28, 1895 – December 2, 1981) was an American architect.
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United Nations Building
The United Nations Building in New York was the first major international building to be constructed after the war.
A multinational advisory committee was established for the design of the building. It was composed of a number of leading architects, including Le Corbusier.
The director of planning and lead architect was Wallace K. Harrison who helped design tall buildings such as Rockerfeller Center before the war. During the development of the scheme, Harrison was involved in a number of conflicts with Le Corbusier, who allegedly claimed credit for the design concept. One such argument involved protection of the offices in the Secretariat (Tower) Building against excessive solar heat gain and glare. Le Corbusier had preferred stone facades but the board preferred to maximize sun and natural daylight using overall glazing. They decided this could be achieved best with curtain walling, even though at the time it was an unusual solution for a skyscraper.
The Equitable Building was the only example of a continuous glazed curtain wall in the country and “even in those energy rich days this much glass raised the question of heat gain and loss.” They considered four different glazing options in conjunction with internal venetian blinds.
These included single and double-glazing with and without tinted glass. Le Corbusier thought that the tower building should be protected from the sun by brise-soleil. Brise-soleil eventually were eliminated because snow and ice collecting on them in winter would create a hazard.
To select the best of the glazing options, Harrison turned the problem over to the mechanical engineers Syska & Hennessy. They conducted an experiment by placing recording thermometers in front of two windows, one with tinted glass and the other without, oriented as they would be in the building. After two weeks the thermometer behind the tinted glass had consistently recorded a temperature of 5.5°K to 8.5°K (10°F to 15°F) lower. This convinced Harrison that tinted glass without brise-soleil could moderate the heat and cold and justify its extra cost.
In hindsight this appears to be a huge leap in logic. However, the internal environment did not rely on tinted glass alone. The windows had venetian blinds on the inside and 4,000 of the new “Carrier Weathermaster” high-velocity induction units beneath the sills. Up to the time when these units became available, large building air-conditioning systems were almost invariably all-air and had correspondingly large ducts.
Carrier recognized the problem in the 1920s and decided that high velocity air was the answer. He did not pursue it atthe time but developed a range of room terminal units intended to reduce the total volume of air by supplying primary air at a lower temperature and mixing it with room air.
It was not until 1937 that he developed the idea further. Patents were applied for and the first installations were completed in 1940, only months before the United States entered the war and new building construction virtually ceased.
The application of this type of “air and water” terminal unit method of air conditioning was another important advance. The air and water induction unit air-conditioning system had three main advantages over the all-air systems at the time:
- Most heat gain and loss from the building is through the window and the under-sill location of the units compensates with minimal effect on the room condition.
- Heating and cooling energy is transported around the building by water, a much more efficient medium than earlier systems that used air.
- Considerably less vertical duct space is required, as the main supply ducts operate at high velocity and only handle enough air to meet the minimum fresh air ventilation requirements.
The location of the unit beneath the window and how the horizontal ducts connecting to the units were concealed, on the floor below, in ceiling voids formed by the now ubiquitous, acoustic ceiling tiles.
Despite problems with the curtain walling, the combination of tinted glass, venetian blinds and a high velocity perimeter induction unit system must have worked well, as it was repeated on numerous buildings for the next 20 or 30 years. Peculiarly though, for an air-conditioned building, the windows in the tower were operable although no reason seems to have been recorded why they did not follow the pattern set by Belluschi.
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