Building Typology: Hotels

Engineering Solutions

Energy Recovery Analysis Tools

Summary:

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.

Spreadsheet tools available for download on this page have been developed to make energy recovery analysis in retrofit planning easier and increase awareness for energy recovery in initial project planning and data collection. The tools provided are not comprehensive design tools but can generate inputs for energy and financial analyses used in investment decision making.

While these spreadsheet tools may be used for any building type, they were developed with existing, large commercial and multi-family properties in mind. Recommended users include staff within the building owner’s organization (e.g., facility manager, chief engineer, energy manager) or consultants supporting a building owner to develop a strategic decarbonization plan.

Source and Sink Inventory Tool

Purpose: Identify locations where waste energy can be captured (sources) and where the recovered energy can be applied (sinks) for evaluation during the retrofit planning process.

Phase: This tool is best used during the Pre-Planning phase when examining a building’s current conditions.

Inputs: Targeted existing condition information from the building’s systems.

Outputs: Transparent characterization and documentation of energy recovery and renewable heat sources relevant to the building to support energy analysis in following phases.

Download Source & Sinks Inventory Tool

Energy Recovery Mapping Tool

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:

Uses 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. 

Download Energy Recovery Mapping Tool

Source: RMI

Tags

Engineering Solutions

Charrette Templates: Supporting Preliminary Retrofit Plan Review

Charrette Overview

A charrette is a focused, collaborative convening of diverse stakeholders. In planning a building decarbonization project, charrettes are a powerful tool for establishing a holistic understanding of a building’s existing conditions and needs, aligning stakeholders, developing creative solutions, and accelerating the retrofit design process.

Context

While charrettes can be used within multiple contexts, this resource has been developed to support the review of a preliminary retrofit plan. The preliminary retrofit plan scope is developed based on existing building conditions, high-level energy data and calculations, as well as the team’s expertise and prior project experience. Having a charrette at this point in the process allows for early feedback about the retrofit scope and alignment with project goals. It provides an opportunity for collaborative problem-solving and the development of creative solutions, as multi-disciplinary stakeholders are brought together to iterate on the retrofit. More detailed energy and financial analysis will occur after the charrette and may drive scope change as the team uses results to optimize the retrofit.

Templates Overview

The following templates have been developed to reduce the effort required to include a charrette in retrofit planning and guide project teams through the charrette process. The format of the templates is intentionally basic so your organization(s)’ presentation format and logos can easily be added.

The templates are intended to be used by the design team to gather feedback and develop consensus from project stakeholders on the following topics:

  • Project goals
  • Retrofit triggers
  • Proposed retrofit plan

Three templates are available for download and are designed to work together. These include:

Pre-Read Template: Use this template to develop a project-specific pre-read document that can help inform the charrette discussion. This template offers a preset agenda for the charrette and provides space to clearly define project goals, trigger events, and a high-level summary of the retrofit plan. To maximize benefit from the charrette it is important that attendees arrive with a solid understanding of the information provided in the pre-read. Therefore, it is recommended the document remain as concise as possible and is sent to attendees with sufficient time for them to review.

Download the Pre-Read Template

Charrette Presentation Template: This easily customizable slide deck template provides a framework and content to guide project teams through the charrette. The intended outcomes from the charrette are level setting stakeholders on the project’s status and plans, collecting feedback, and ideation.

Download the Presentation Template

Post-Charrette Report Template: Use this template to capture outputs from the charrette and distribute to project stakeholders. The report is intended to support the team in coming to consensus on goals, retrofit triggers, and the preliminary retrofit plan. Once finalized, it can be used as a basis for moving into the detailed analysis phase.

Download the Post-Read Template

Source: RMI

Tags