The report, “System Optimization of Residential Ventilation, Space Conditioning and Thermal Distribution,” identified and evaluated system integration concepts for low-rise residential structures and ranked them in order of merit. Of the more than 30 concepts ranked, topping the list were:
- Load solar gain windows
- Roofing with reduced heat gain characteristics
- Proper sizing to load
- Reduced infiltration with controlled ventilation.
Of the various mechanical systems available, ranking at the top were:
- Ductless mini-split systems
- Integrated heating, cooling, dehumidification and ventilation systems
- ERV/HRVs coupled with reduced infiltration
- Frostless heat pumps
- Matched components to combined efficiency
- Evaportively cooled condensers
- Improved aerodynamics (low watt per draw cfm) of the air handler/furnace and the outdoor a/c unit
- Higher SEER
- Combined space and water heating
Time, performance and costs ranked as the top barriers to optimal system design.