ET26SWG0006 - Spa Heating Analysis Literature Review and Market Assessment

Spas or hot tubs are normally used year-round, unlike heated pools. Spas typically maintain water temperatures between100-104 F which require fast heating for better customer experience. Spa heating and pool-spa configurations generally involve how the water is heated and circulated between pool and spa. This project aims to research standalone spas and types of pool-spa configurations (mentioned below) in residential, multifamily, and commercial sectors:

a) Standalone spa (in-ground and above-ground)- more common in residential sectors
b) Integrated spa built into the pool structure- switching between pool and spa modes via automated valves
c) Attached pool-spa with different circulation loops
d) Isolated pool-spa with separate/dedicated heaters and flow configurations

The study aims to provide comprehensive comparison on sizing of equipment, equipment costs, and temperature control for above configurations. The study also aims to research reference heat transfer equations and associated modeling assumptions to account conduction heat transfer, which is a significant heat loss in above-ground spas compared to in-ground heated pools. One of the other objectives would be to study recommended flow rates/turnovers of jet pumps and insulated covers for commercially available spa heating equipment