Climate Design Spreadsheet Calculators
Sponsored by Idaho Power, the University of Idaho Integrated Design Lab (UI-IDL) has developed two generations of spreadsheet calculators that can analyzing building loads and energy consumption impacts of a range of different design strategies over four reference cities. You can also download our technical reports, which provide information about our development methodology and how to use the tools most effectively.
There are currently seven calculation spreadsheets:
First Generation Tools
- Heat Gain Calculations
- Cross Ventilation
- Stack Ventilation
- Night Ventilation Thermal Mass
Second Generation Tools
- Balance Point Calculation
- Passive Solar
- Earth Tube
Each spreadsheet contains multiple tabs and a step-by-step process that directs the user to define the critical baseline and performance parameters of the building. These factors are linked to pre-defined equations within the spreadsheet that automatically provide the peak cooling loads, cooling capacities and describe other critical design criteria. Charts, line graphs and other forms of graphic information also automatically populate the workspace to provide rich visual feedback to the user.
The spreadsheets also contain a reference tab that consolidates a myriad of textbook, code and other sources needed to complete the step-by-step instructions. Additionally, a variety of weather data, including hourly information from TMY weather files, are embedded into the calculations based on three different reference cities within the Idaho Power service area.
Once each tab is filled out, the results pages of the spreadsheets contain all the important outputs needed to evaluate how much the passive design measure can contribute to the peak loads or energy savings of the building. Changes to the building parameters are instantaneous, making the Climate Tools Package an ideal instrument used to explore different design iterations and how they might facilitate passive design strategies.
The ultimate goal of the Climate Tools Package is to reduce the loads and energy consumption of a building through passive design measures. This happens mainly by embedding, early in the design process, the analysis of the performance capabilities of different passive cooling and heating strategies. Once a performance capacity is calculated and compared against peak loads of a building, a qualitative decision can be made about pursuing more detailed analysis. If certain passive strategies are proven to meet some or all of the peak load, this may warrant further development. Potential next steps could involve more advanced analysis such as building simulation to quantify annual energy savings based on actual weather data.