This article maps the standards used and assumptions made for cove.tool's automated energy model generation.
How does it work?
Cove.tool follows 4 practices to auto-populate the entirety of your baseline energy model. They are:
First, based on the user's energy code selection, cove.tool populates code prescriptive values such as envelope, lighting, and ventilation rates.
Second, for parameters like EPD (appliance use), total occupants, and occupancy schedule the tool uses values listed in ASHRAE 90.1 - User's Manual.
Third, PNNL Model Prototypes are used to calibrate parameters not regulated by the selected energy code, such as LPD Unoccupied, DHW Demand, etc. Some energy codes after 2016 have begun listing parameters, such as Fan Control, Pump Control, and Sensors. All earlier version remains calibrated values.
Last, industry-standard values are used to define any remaining values. Users can edit these values so that they reflect the project's design intent.
For more information on Building System inputs see this article. For locations outside of the US, equivalent standards and guidelines are used to autofill the baseline assumptions. More on international compatibility here.
Talking to an Engineer
While the section above explains how the default inputs are populated into the platform, it is also important to keep in mind how the results are generated. cove.tool's primary baseline energy analysis is an early-stage single-zone simulation using the ISO 13790 Standard heat-balance engine. The more advanced loadmodeling.tool uses the EnergyPlus version 9.5 engine for detailed, room-by-room load calculations and HVAC system sizing. cove.tool has validated both software's using the industry-standard testing procedure known as the ASHRAE Standard 140 report, which can be provided upon user request. Also the loadmodeling.tool is compliant with ASHRAE 183 for Peak Heating and Cooling calculations. By combining both tools in one package, input data and results from system design calculations can be used in early energy modeling studies to check efficiency and costs.
Overall questions that cove.tool can answer:
Will this system type save me some energy?
While saving energy, does it have a payback?
Questions the tool cannot answer:
Should I have a fan coil in room #237?
What is the peak cooling load for my building?