When a house is listed for sale in Colorado, the seller can fill out a green disclosure form to indicate what "green" or environmentally friendly qualities the house has. Many of the terms on the form are specific terms, often abbreviated, that may be unclear. Let's go over them and discuss what they mean.
The third item is "Heating, Cooling and Ventilation." The form's options are: Ground Source Heat Pump, Tankless/On Demand Water Heater, Evaporative Cooling, High SEER A/C (with a line for SEER Rating), High Efficiency Furnace/Boiler, High Efficiency Water Heater, Whole House Fan, Ceiling Fans, Insulation Air Sealing Upgrades Completed, and Home Orientation (South Facing Overhangs).
"Ground source heat pumps" are systems in which a loop of pipe filled with some liquid, often water, is used to bring heat from the ground in winter and to send heat from the house to the ground in summer. Read more about these systems at the International Ground Source Heat Pump Association's site, http://www.igshpa.okstate.edu/geothermal/
"Tankless/On demand water heaters" are small heating units installed close to sinks or bathtubs, and sometimes washers. Cold water travels through the pipes until it reaches the heater, which is close to the faucet. The heater warms up the water on its way to the faucet. Some people don't like having a lower flow of hot water, but they do like that it is cheaper because water is not kept warm when no one needs it. More information is available at the Energy.gov site, http://energy.gov/energysaver/articles/tankless-or-demand-type-water-heaters
"Evaporative cooling" means using the process of evaporating water to cool the air in a dry, hot climate. Because evaporative cooling requires low humidity, it is not suitable for all climates. But in places like western Colorado or central California this can be used effectively. Evaporative cooling can use as little as a quarter of the energy that an air conditioning system requires. People in the desert enjoy the cool damp air that circulates through the house. It keeps furniture from drying out. People in the Grand Valley enjoy it and it goes well with heating systems that use hot water baseboard heat. These houses don't need a forced air duct system. More detail is available at the Consumer Energy Center, http://www.consumerenergycenter.org/home/heating_cooling/evaporative.html
"High SEER A/C" means that a home has an air conditioning unit with a high SEER. "SEER" means Seasonal Energy Efficiency Rating, determined by the ratio of cooling accomplished to amount of energy consumed to accomplish it. The Department of Energy's standards currently require that all new air conditioning units have a SEER of at least 13, a 30% improvement in efficiency from the previous minimum standard of 10. Some air conditioners available now have SEERs as high as 23. Read more at Energy.gov, http://energy.gov/energysaver/articles/central-air-conditioning
A "high efficiency furnace/boiler" is one that is considered efficient based on its Annual Fuel Utilization Efficiency (AFUE). AFUE is calculated by looking at how much of the energy used by a furnace or boiler produces heat for the building and how much is lost. Units with 90-98.5% AFUE are considered highly efficient. A table with current minimum AFUE standards and more information is available at http://energy.gov/energysaver/articles/central-air-conditioning
A "high efficiency water heater" uses 10-50% less energy than a standard model. The Department of Energy has formulas for calculating the efficiency of your water heater at http://energy.gov/energysaver/articles/estimating-costs-and-efficiency-storage-demand-and-heat-pump-water-heaters (As a more straightforward way of evaluating your unit, any water heater with an ENERGY STAR rating is considered highly efficient.)
"Whole house fan" means the use of a fan in a building's ceiling to cool the building by circulating air and venting it through the attic and roof. A whole house fan can function in place of an air conditioner in many climates and has the advantage of providing good attic ventilation. More information can be found at Energy.gov, http://energy.gov/energysaver/articles/cooling-whole-house-fan
"Ceiling fans" are common features in many homes which can be used to help keep residents cool in summer and warm in winter. Although a ceiling fan doesn't change the ambient temperature of a room the way an air conditioner or heater does, it moves air around in a way that feels cooler or warmer. http://www.energystar.gov/index.cfm?fuseaction=find_a_product.showProductGroup&pgw_code=CF
"Insulation air sealing upgrades completed" means you've accomplished changes in insulation and air sealing, usually as recommended in the Home Performance with ENERGY STAR evaluation, discussed in the first post in this series at http://grandjunctionbroker.blogspot.com/2013/05/colorado-green-disclosures-item-1.html
"Home orientation (south facing overhangs)" means that the house is situated in a way that maximizes a gain of solar heat in the winter and shade in the summer. A south-facing orientation, defined as being within 30 degrees east or west of true south, with large windows picks up solar heat to warm the house in the winter, especially if windows or floors are made of materials which absorb heat. Overhangs that shade the windows in summer help keep the house cooler. You can read more at Energy.gov's Passive Solar page, http://energy.gov/energysaver/articles/passive-solar-home-design
