March 9, 2022
The following applies to all users of the EnerGuide Rating System and ENERGY STAR for New Homes.
This bulletin provides important updates to the EnerGuide Rating System (ERS) pertaining to the modelling of cold climate air source heat pumps in HOT2000. Please ensure this information is distributed to your energy advisors, quality assurance specialists and energy advisor candidates.
When following the modelling procedures for cold climate air source heat pumps (ccASHPs) as per Program Bulletin #78 and the EnerGuide Rating System—HOT2000 User Guide—Version 15.10 (or later), the adjusted heating COP may be lower than 3.45. This will cause the file to be rejected by the mailbot when the ENERGY STAR box is checked in HOT2000 for the ccASHP. The mailbot rejection note is as follows:
“An ENERGY STAR qualified air-source heat pump was specified but the HSPF is less than 7.1 for region 5 of Canada. Please correct the file and resubmit.”
When checking the ENERGY STAR box is required to trigger a grant, please submit the file to ManuEval with the following information and include “ccASHP” in the email subject line:
When checking the ENERGY STAR box is not required to trigger a grant, the file can be submitted to the mailbot normally without the box checked.
Note: This issue does not affect files submitted through the HOT2000 File Submission and management Portal (the web-based system). Follow ERS procedures when checking the ENERGY STAR box for files submitted through the Portal.
The following improvements have been made to the ccASHP calculation spreadsheet:
The updated Heat Pump Calculator – Calculateur pour thermopompe replaces the one released in Program Bulletin #78 and contained in the HOT2000 User Guide—Version 15.10 Appendix E. Use of the updated calculation spreadsheet is mandatory immediately for modelling ccASHPs and combinations of ccASHPs and ASHPs. The spreadsheet may also be used to calculate weighted averages when multiple ASHPs were evaluated as an alternative to the instructions contained in the Technical Procedures—Version 15.10 section 3.10.3. This new calculation spreadsheet will also be included in the next release of ERS documents.
As required, the Heat Pump Calculator – Calculateur pour thermopompe must be retained and available, such as for ManuEval, third-party quality assurance, and for uploading to the Greener Homes Partner portal as supporting documentation. Customized spreadsheets will not be accepted. The Heat Pump Calculator – Calculateur pour thermopompe document may be downloaded from the Members Only Resource Centre or Google Drive at https://drive.google.com/drive/folders/1zH1Mb_2G5jpJqU-lnGUK1e3RMhOVkpSe.
When using the ccASHP modelling procedure (i.e. using adjusted values from the calculation spreadsheet) there are situations where the ERS Rating may not improve when compared to using the non-ccASHP modelling procedure. When heat pumps are modelled using HSPF, HOT2000 estimates a corresponding nominal COP that is then used to perform the simulation. However, there is no direct relationship between the nominal COP (which is a value at 8.3 °C) and the HSPF (which is a seasonal average). For example, for an HSPF of 8.7, the NEEP database contains ccASHPs with nominal COPs varying from 1.9 to 7.3. Since HOT2000 calculates a nominal COP of 4 for this HSPF of 8.7, a significant number of ccASHPs see their COP reduced when using the spreadsheet (i.e. those for which the COP is larger than 4 up to 7.3).
The results from the Heat Pump Calculator – Calculateur pour thermopompe are more accurate since it uses an adjusted COP derived from measured values and not an approximation derived from the HSPF. Furthermore, the adjustments of the capacity and COP performed by the spreadsheet ensure that the average capacity and COP calculated by HOT2000 over the heating season corresponds to the values observed for the studied ccASHP operating in the same climate. The pertinence of these adjustments was demonstrated during validation of the method where, for a wide range of buildings, climates, and heat pumps, the root mean square of the error went from about 8% to 2% when using the adjusted capacity and COP from the spreadsheet. The ERS Rating could be better or worse when compared to the non-ccASHP modelling procedure. Please refer to the updated Heat Pump Calculator – Calculateur pour thermopompe for instructions on how to model ccASHPs.
The Modelling air source heat pumps and cold climate air source heat pumps in HOT2000 presentation has been updated to reflect the latest information in the Greener Homes Information Manual for Service Organizations and Energy Advisors version 2. The presentation provides detailed procedures for modelling heat pumps for the EnerGuide Rating System and additional examples in the context of Canada Greener Homes Grant initiative. The updated presentation may be downloaded from the Members-only site or Google Drive at https://drive.google.com/drive/folders/1zH1Mb_2G5jpJqU-lnGUK1e3RMhOVkpSe.
If you have questions, please contact your account manager.