Research Courtesy of Jim Logan Architects
Provided By Stu Galvis, EcoBroker
Boulder Green Properties
A team within Keller Williams FRP
Energy Efficient Retrofits by Priority of Return on Investment
Evaporative Cooling instead of Air Conditioning
Evaporative cooling uses one-fourth the energy of typical air-source air conditioning, with a lower initial cost.
Reduce Air Leakage to 0.3ACH
Blower door testing with caulking and sealing of the building can reduce the air leakage -- the amount of outside air to
be heated and cooled. Spray insulations, such as wet-blown cellulose and icynene, reduce air leakage by filling gaps in
the framing. An initial reduction from 0.6 air changes per hour to 0.3 is easily attainable in both new and existing
Low E Windows, Passive Solar Tempered
Changing the glass to double low-E reduces both heating and cooling loads. In this step, we have increased the South
glazing to 8% of the floor area. The South glass has a high solar heat gain coefficient (0.6) -- allowing 60% of the heat
from the sun into the building during winter months and reducing our heating load.
Electrical and Hot Water Efficiency
Use Energy Star labeled appliances and electronically ballasted fluorescent lighting. Hot water use can be minimized
with low-flow fixtures and efficient delivery systems.
Increase Roof Insulation to R-50
Typical roof construction often has a large enough cavity to allow increasing the amount of insulation from the R-38
typically required by code to R-50.
Reduce Air Leakage to 0.15 ACH
Further caulking and sealing in new construction can lower the air leakage to 0.15 air changes per hour. At these low
levels of leakage an air-to-air heat recovery ventilator is typically added to ensure good indoor air quality.
With the Xcel rebates, photovoltaic energy supply is more cos