What is this guidance about?

Publicly Available Specifications (PAS) are best practice documents developed by Standards New Zealand along with EECA, industry, and other experts.  This best practice guidance is for installers, engineers, and building managers who help choose and set up high-temperature heat pumps in homes, businesses, or industrial sites. The PAS also includes some helpful information for homeowners and customers who want to understand the basics. The applications covered include: 

  • Residential water heating. 
  • Commercial-scale potable water, space heating, pool heating, and fresh-air tempering. 
  • Industrial process heat. 

Whether you’re looking for a high-temperature heat pump for an industrial process or for more energy-efficient space or water heating, this guide will help you make informed decisions. It covers key considerations for each purpose such as system efficiency, refrigerants, and running temperatures. 

Benefits of a high-temperature heat pump   

Selecting the right high-temperature heat pump for the purpose is important for maximising energy efficiency and ensuring cost-effectiveness. The PAS outlines why careful selection of high-temperature heat pumps is important: 

  • High-efficiency high-temperature heat pumps can deliver the same amount of heating with a lower electrical demand and so lowering running costs.  
  • Integrating with sophisticated control systems when there is variable heating demand prevents inefficiencies and excessive electrical energy used. 
  • Allowing for the recovery and upgrade of waste heat and/or cooling capacity in sophisticated installations can help to increase the efficiency of the whole system. 
  • Designing systems to minimise temperature lift and optimise heat-source/heat-sink conditions can significantly increase system efficiency. 

Important high-temperature heat pump considerations 

As explained in the PAS, key features to consider when selecting a high- temperature heat pump include: 

  • The temperature constraints of the refrigerants and the ambient temperature ranges of your location. 
  • The capacity of the high-temperature heat pump needs to meet your specific demand.  
  • Making sure that the system can meet demand even on the coldest days. This may mean including auxiliary heating or thermal storage instead of oversizing the heat pump. 

Tips for selection 

  • Evaluate total lifecycle costs — consider not just upfront installation costs but also maintenance and running costs. 
  • Ensure suitability — consider what size, refrigerant, and operational requirements you may need. 
  • Think ahead — how will this technology work for you in the future? Will it continue to meet your demand? 

Ready to get started?

Before procuring a high-temperature heat pump, it’s important to understand the key technical and operational considerations.  

Here’s what to look for in the PAS: 

  • General information – Sections1 and 2 explain what high-temperature heat pumps are and why they matter. 
  • Residential use (hot water) – See Sections 3 - 6  
  • Commercial applications – Start at Section 7, with specific uses in Sections 9 – 12  
  • Industrial process heat – See Section 13. 
  • Refrigerants – covered in Appendix A and throughout. 
  • Performance and cost modelling – See Appendix D. 

Check out the detailed guidance here. This link will take you to the Standards New Zealand website where you can download the PAS at no cost.