Chuck, go to Hyatt corporate as they generally have their guideline posted within their design criteria.
3D Engineering Consultants, LLC
David Dexter, F.NSPE, F.ASPE
Registered Professional Engineer
Mechanical, Plumbing & Fire Protection
Cell: (937) 609-5969
Sr. Plumbing Designer
I can tell you there was a great deal of dispute over some new research on sizing hot water systems for hotels just published in the 2019 ASHRAE Handbook chapter on water heating. What it says is:
Hotels. Hotel hot water uses tend to be grouped into three major
categories: (l) guest room circuit, (2) laundry circuit, and (3) food
service/commercial kitchen circuit. Guest room circuits tend to have
the following hot water loads: (1) guest showers and baths, (2) guest
room sink use, (3) guest room cleaning, and (4) common area
cleaning. Bathing (showers and baths) is the largest single hotel hot water
use category, often exceeding all other hot-water uses combined,
Research results from Hiller and Johnson (2015, 2016a,
2016b,2016c,2017a,2017b) present findings on a study of a large
conference hotel and a roadside travel hotel. The work provides
guidance on sizing of the water heating system, including storage
volumes and heating rates of water heaters, based on these two studies.
ASHRAE members can obtain copies of RP-1544 reports at no
cost via the ASHRAE Technology Portal (technologyportal.
This research is new and has not been used much if at all, so be careful. The references go into great detail.
Larry Spielvogel, PEL. G. Spielvogel, Inc.190 Presidential Blvd # 310Bala Cynwyd, PA 19004-1151Phone: 610-664-2407; Cell: 215-620-1234Fax: 610-664-2406; Email: email@example.com