The HeatSmart Alliance Heat Load Analysis (HLA) tool estimates a home’s heat load based on its heating-fuel usage, estimated heating-system efficiency, and a few other inputs. A trained and experienced user of the HLA tool can produce results in less than 15 minutes.

This tool complements Manual J modeling of a home’s heat load. Manual J requires dimensions of the home, estimates of infiltration and the thermal properties  (R and U values) of various building envelope components, and other inputs. A thorough Manual J analysis can take several hours.

The output from the HLA tool provides:

• A benchmark of a home’s weatherization relative to other homes of its size
• A rough check on the total heating capacity of proposed heat pump systems

The HLA tool currently supports fuel oil, natural gas and propane. It includes temperature data for six weather stations in eastern Massachusetts from 2011 through July, 2024. For benchmarking, the tool includes results for over 90 homes previously analyzed. It provides the total heat load of a free-standing home; it cannot provide room-by-room heat load and has not been applied to multi-family homes.

The HLA tool is implemented as an Excel template. Always start by downloading the template via the request form; copies from elsewhere may be outdated, modified or malware-corrupted. New users should watch the training videos and demonstrations linked below before attempting to use the template.

• Videos about HLA (watch parts 1 and 2 first)
  • Training, Part 1 10 min
  • Training, Part 2 10 min
  • Demonstration for fuel oil 7 min
  • Demonstration for natural gas 11 min
• Instructions to National Grid gas customers for downloading usage to a .csv file (.pdf)
• Demonstration for Eversource gas customers of downloading usage to a . csv file