Heating & Cooling
District heating systems provide economies of scale in large cities like Copenhagen.
HVAC—heating, cooling, and ventilation—is responsible for more than a third of energy use in commercial buildings in the U.S. Smart designs can easily save upwards of 40% of that energy, often with strategies that offer instant or short payback. And good design that focuses on thermal comfort supports healthier, more productive occupants.
Heating & Cooling
Deep Dives
Get up to speed on complex topics. You can also earn CEUs and download PDF Spotlight Reports.
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The Cost of Comfort: Climate Change and Refrigerants
Feature Article
Refrigerants with very high global warming potential can negate the energy-efficiency benefits of many HVAC systems, including popular heat pumps.
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Are Cool Roofs Green? The Answer’s Not Black and White
Feature Article
Roofing choices are complicated by heating tradeoffs, climate effects, and condensation, but proponents say reflective roofs still make sense in most climates.
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Passive Solar Heating
Feature Article
Using the sun for most of a building's heating needs is in the DNA of green building. But in an age of superinsulation, does it still make sense?
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Solar Thermal Hot Water, Heating, and Cooling
Feature Article
By creating heat instead of electricity, solar thermal achieves three times the efficiency of photovoltaics at a lower price.
Quick Takes
Jump straight to the essentials with these short explanations of green building concepts.
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Air-to-Balcony-to-Water "Bridging" Heat Exchanger
Infographic
Heat and cool totally go where the arrows point. Always. But before you rely on this detail, check the date we published it.
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New Refrigerants, Less Global Warming
Primer
HFOs usher in a new era of refrigerants and foam insulation blowing agents with low global warming potential.
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How Air-Source Heat Pumps Work
Primer
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?
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How Blower-Door Tests Measure Airtightness
Primer
Blower-door tests: what they are, how they work, and understanding airtightness measurements.
Product Guidance
Unbiased information from our product experts helps you separate green from greenwash.
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Innovative Heat Pump Replaces Window Air Conditioners
Product Review
Gradient is introducing an integrated heat pump that fits into a window opening, but unlike a standard AC unit, it can also supply heat during winter months.
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Commercial Heat Pump Water Heaters Using CO2 Refrigerant
Product Review
Mitsubishi’s Heat2O commercial heat-pump water heater uses CO2 as a refrigerant and is now available in the U.S.
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A Plug-and-Play Hydronic System that Captures VRF Waste Heat
Product Review
The LG Hydro Kit, now sized for residential and multi-family use, captures waste heat from its Multi V heat pumps to provide a fossil-fuel-free source of hot and cold water for space heating or domestic hot water.
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Mag Lev Chiller uses Low-Global-Warming-Potential Refrigerant
Product Review
YORK YZ Magnetic Bearing Centrifugal Chiller is the first chiller to be optimized for use with a low-GWP hydrofluoroolefin (HFO) refrigerant.
In The News
We break news down to the essentials and provide expert analysis.
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ASHRAE Releases COVID-19 Recommendations
News Brief
ASHRAE offers guidance on how to reduce the spread of COVID-19 through HVAC systems.
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Old Insulation and HVAC Systems Are Still Depleting Ozone
News Brief
Older buildings are “CFC banks” because of phased-out refrigerants and blowing agents, according to MIT scientists.
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EPA Rolls Back Obama-era Refrigerant Rule
News Brief
Under a new EPA ruling, large commercial HVAC and refrigeration systems will no longer have to address high-GWP refrigerant leaks.
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Engineers Post Electrification Equipment Wish List
News Brief
Twenty-four MEP firms are entreating manufacturers to make products needed for all-electric buildings, like large capacity heat pumps.
Perspective
Thought-provoking opinions from the most trusted minds in sustainability.
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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.
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Questioning Active Chilled Beams
Op-Ed
Energy consultant Andy Shapiro questions the energy benefits of active chilled beams; engineer Peter Rumsey responds.
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Drinking the Heat Pump Kool-Aid
Op-Ed
Reader Thomas McGrath questions the choice of heat pumps over other forms of space heating.
Learning Resources
Syllabus supplements and CEU content, with automatic reporting for AIA and GBCI.
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Are Cool Roofs Green? The Answer’s Not Black and White
Feature Article
Roofing choices are complicated by heating tradeoffs, climate effects, and condensation, but proponents say reflective roofs still make sense in most climates.
