Hear about Donnel Baird's ambitious plan to rip the fossil fuel infrastructure out of aging buildings and upgrade it with smarter, cleaner, healthier technology.

Rain, a startup building aerial fire-fighting tech, has closed a seed-round of 9.7 million led by DBL partners.

Boston-based metals refining company Nth Cycle has closed $44 million in new funding that was supported by several investors, including the Caterpillar Ventures subsidiary of heavy equipment maker Caterpillar Inc.