In an inconspicuous room off of the galleries on at the AIA Center for Architecture on La Guardia street, the mechanical room might not appear innovative at first glance. But, as the information panels in a small display explain to visitors, the room houses part of the geothermal system that helps cool and heat the building.
This system is very different from what is used in Iceland. Here the ground is used as a heat regulator rather than as a source of very hot water.
There are two wells that both run 1,260 ft into the ground. The pipes draw water up through a heat exhanger, and then release the water back into the ground. The heat exchanger takes heat out of the water or puts excess heat into it, which moderates the temperature of a water loop that runs through the gallery spaces.
There is no back up system that taps into the grid, should the system have any problems. I visited on a hot, incredibly humid day and it was comfortable in the gallery spaces.
The system shows a bit of wear- it was installed in 2003. But also, it is quite quiet. You can hear the quiet trickle of water flowing in the tube.
The initial cost was $100,000 partially subsidized by a grant from NYSERDA, and their payback period was only 3 years. Compared with many alternative energy scenarios, that is a short payback period. The fact that much of the gallery space is below ground level must mean their heating and cooling demands are already lower than above grade spaces, and furthermore the costs were subsized. But still, it makes you wonder if this strategy is economically feasible for many more buildings than you might expect, or if this a just a unique case…*
* After speaking with a mechanical engineer knowledgeable about these systems, I learned a number of things to consider on this point. The payback period depends on which system you compare it to – on a typical project, you might expect a 3yr payback in comparison to an inefficient alternative, but normally not when compared to normal best practice systems used today. The most commonly quoted payback period for geothermal heat exchange systems in the US is 10-15 years. It’s also important to consider the energy used to run the heat exchanger, as well as for the installation of the wells.