They scattered space heaters in the rooms they wanted to be warmer, a drain on energy and money.

So Kahn sought a solution from Bob Fields, the chief revenue officer at HiberSense, a local startup.

HiberSense installed sensors in all of the rooms, each of which is tied to motorized vents. The vents open and close only when that room needs it, rather than their previous system that pumped air into every room. It also detects motion and adjusts when people enter or leave.

The staff can now keep rooms at slightly different temperatures without having to stand on a chair and adjust the ceiling vents by hand.

It cost a couple of thousand dollars to entirely replace the system, and the office’s energy use has fallen by 30 percent, Fields said.

The vast majority of people who want to make a change do so because they want to be more comfortable, Fields said. One side of their office is too cold, and another is too hot. For most people, he said, it’s a side benefit that they may save money or help the environment.

Long-term accounting

But in the long term, Phipps Conservatory Executive Director Richard Piacentini said companies need to bring the natural environment into their work spaces.

Piacentini has been trying to use Phipps as a model for what buildings in the city could be like. The main office, the Center for Sustainable Landscapes, produces more energy than it uses.

It has solar panels, a green roof and geothermal heating. On a recent day in December, there wasn’t a single overhead light on in their office space because the abundance of windows brought in so much natural light.