Heating & Cooling

District heating systems provide economies of scale in large cities like Copenhagen.

Photo: Bill Ebbesen. License: CC BY 3.0.


Energy-efficient HVAC design is a fundamental of green building, for good reason:

  • The scale of the issue: HVAC is responsible for more than a third of energy use in commercial buildings in the U.S.

  • The scale of returns: Smart designs can easily save upwards of 40% of that energy, often with strategies that offer instant or short “payback.”

  • The human impact: Discomfort from spaces that are too hot or too cold, and lack of adequate ventilation, are an epidemic. Good design that fixes these problems supports healthier, more productive occupants.

Don’t make the all-too-common mistake of thinking of HVAC design separately from building envelope design. Over-glazed buildings lead to oversized mechanical systems, increasing costs on both fronts. A tight, well-insulated envelope may cost a bit more but can pay for itself with less mechanical equipment.

  • New Refrigerants, Less Global Warming


    HFOs usher in a new era of refrigerants and foam insulation blowing agents with low global warming potential.

  • Climate Analysis for Architects


    For a lot of people, computer modeling is synonymous with energy modeling, and climate data is something you just input to your energy model. Kjell Anderson wants you to do energy modeling for your buildings, and he wants you to do it early—as BuildingGreen has advocated—not just for "keeping score" at the end. In this webcast, Anderson will demonstrate tools that are so easy that they can be used on every project regardless of budget or sustainability objectives, typically taking 3 to 5 hours once you have your system down—and almost no time for projects in a city where you have already done an analysis.

  • How Air-Source Heat Pumps Work


    Heating with cold air? Cooling off with hot air? Heat pumps performing these feats (especially mini-splits and VRF systems) have taken off, but how do they work?

  • 7 Tips to Get More from Mini-Split Heat Pumps in Colder Climates

    Blog Post

    Air-to-air heat pumps are getting more popular as a primary heat source in colder climates. Here’s how to get the most from your system.

  • How Blower-Door Tests Measure Airtightness


    Blower-door tests: what they are, how they work, and understanding airtightness measurements.

  • Questioning Active Chilled Beams


    Energy consultant Andy Shapiro questions the energy benefits of active chilled beams; engineer Peter Rumsey responds.

  • Radiant Floor Heating: Wrong Choice for Green Homes?


    While very popular, radiant-floor heating is not well-suited to highly insulated, green homes.

  • Drinking the Heat Pump Kool-Aid


    Reader Thomas McGrath questions the choice of heat pumps over other forms of space heating.

  • Comparing Fuel Costs


    One would think comparing the costs of different heating fuels would be simple, but figuring out the amount heat available in a given quantity of fuel-and the associated cost-can be tricky.

  • Evaporative Coolers


    As water evaporates, it absorbs heat. Direct and indirect evaporative coolers use this property to cool homes efficiently.