An article in the New York Times asks, “Why is America so over air-conditioned?” Several experts interviewed for the article say the problem is cultural: there is a perceived cachet and prestige to excessive air conditioning.
Commercial real estate brokers and building managers say many high-end tenants such as jewelry stores and clothing retailers actually specify high chilling capacity in their lease agreements, according to the article.
The problem is customers of these retail establishments as well as workers in office buildings really hate the freezing temperatures. They have to resort to wearing layers even when the weather is hot.
Aside from the supposed “cachet,” the problem is also compounded by building managers who don’t adjust the temperature set point higher in summer than they do in winter, even though people wear lighter clothing in summer.
Also, air-conditioning systems may not be set for appropriate heat loads. They could be set for full occupancy of a space on the hottest day of the year and without factoring in newer, less-heat-emitting computers and lighting. In addition, ventilation codes may keep air-conditioning blasting in order to meet mandated air quality standards. This problem can sometimes stem from the best of intentions: a building is so well-insulated for energy efficiency that it fails to let in enough outside air and then needs more mechanical ventilation.
A chairwoman of the ASHRAE committee that develops standards for human thermal comfort told the NY Times, “We have a lot of data that people are most comfortable if they have some measure of control.”
One technique cited in the article is to employ Building Robotics‘ Comfy to tune HVAC to occupant requests to eliminate unnecessary air-conditioning. Utilizing data from occupant requests, Comfy teaches the building control system to adjust temperature setpoints in specific zones according to occupancy and personal preferences. Over time, Comfy’s learning algorithm optimizes each zone based on occupant requests.
A big side-benefit: cutting back on unwanted air-conditioning saves energy and money.