Recovering waste heat in buildings is a key strategy for improving energy efficiency and reducing remissions. Many building systems, such as cooling equipment, wastewater, and ventilation reject heat that has the potential to be captured and reused in everyday building operations. Mapping these opportunities at the outset ensures that retrofit plans are both efficient, and cost-effective. 

This downloadable energy mapping tool builds on our Energy Sources and Sinks Inventory Tool to help project teams identify and quantify recoverable heat through analysis of building-specific data. While it can be applied to any building type, it was created with large commercial and multifamily properties in mind and is geared toward building owners’ staff and consultants leading decarbonization efforts. See instructions below and download the tool to start evaluating your building’s energy recovery potential.

Purpose: Compare building-specific data for source(s) and sink(s) to estimate potential energy recovery. Default assumptions and data are included to streamline the process. The following common use cases are included in the tool:

1. Capturing heat rejected by the cooling system to improve space heating system performance.
2. Capturing heat rejected by the cooling system to improve domestic hot water (DHW) heating system performance.
3. Capturing heat from wastewater to improve domestic hot water (DHW) heating system performance.
4. Capturing energy from exhaust air to temperature outside ventilation air.

Phase: This spreadsheet tool is intended to supplement other engineering and financial analysis tools during the Planning phase. Additionally, it is recommended the team review the spreadsheet tool during the Pre-Planning phase and identify data collection needs. This is critical, because if data isn’t already being collected the metering will need to be initiated and data collected over a range of operating conditions (e.g. throughout the winter). 

Inputs: Input requirements are dependent on the use case: 

Use cases 1 & 2: Short-interval (e.g., hourly) data for source(s) and sink(s) relevant to the energy recovery use case(s) to be evaluated. The data is typically collected using data trending through the building automation system. Additional metering (e.g., thermal energy “BTU” meters) may need to be installed. Data collected should also be reviewed for accuracy and completeness and normalized for factors such as outside air temperature. If data cannot be collected from the building, explore leveraging an energy model for estimates. 

Use case 3: Attributes about the building’s occupancy, domestic hot water usage, and wastewater.

Use case 4: Attributes about the building’s air distribution system.

Outputs: Annual load and recoverable heat per use case. Data collection initiated to support future heat mapping.

This spreadsheet is not a comprehensive design tool but can generate inputs for energy and financial analyses used in investment decision making.

Waste heat isn’t waste—it’s an untapped resource. Recovering energy that would otherwise be rejected from a building can both reduce greenhouse gas emissions and improve the economics of decarbonization projects. This applies across a range of uses, including space heating, heating ventilation air, and domestic water. To maximize the impact of decarbonization retrofits, it’s essential to consider energy recovery during the planning process. By identifying and thoughtfully integrating heat recovery solutions early on, project teams can reduce energy demand, improve system efficiency, and enhance the overall cost-effectiveness of building upgrades. 

This downloadable spreadsheet tool is designed to help project teams identify and document potential energy recovery opportunities during the pre-planning phase, ensuring these opportunities are captured for analysis later in the retrofit planning process. It is intended to support building owners and their staff, such as facility managers, energy managers, engineers, and consultants advancing decarbonization planning in large commercial and multifamily properties. While this spreadsheet tool was developed with existing, large commercial and multifamily properties in mind, it can be utilized for any building type.

The tool uses targeted information from a building’s existing systems as its inputs, capturing the current conditions that shape retrofit opportunities. The resulting output provides clear documentation of energy recovery and renewable heat sources that create a foundation for analysis in later phases. Download the tool below to unlock your building’s energy recovery potential.

The BEST (Building Energy Simulation Tools) Directory from IBPSA-USA catalogs energy-modeling and simulation software. Tools in the database can support Playbook best practices such as evaluating interactive effects, assessing time-of-day impacts, and accurately sizing equipment. Users can filter by capabilities, platforms, pricing tiers, and building types to identify appropriate tools for retrofit analysis.