sizing hot water systems for nursing homes

kevin miller

I stumbled onto a formula to size domestic hot water systems for nursing homes, quite by accident I might add. This is for upright gas fired boilers, although it may work for other boilers I have not done any calcs. on others. This formula is for facilities with a laundry and dietary dept figured into the equation.
First take the total number of beds and multiply by 12,000 btu, then multiply the number of beds by 3 to get the gals. of hot water storage needed. An example would be a 100 bed facility would need 1,2000,000 total btu's and 300 gals. of hot water storage. The btu and gals I used are on the high end, you could use a lower number like 11,000 and 2 gal per bed. I prefer to use the higher number as well as an extra boiler in the bank to create a redundancy factor for boiler failures and service shutdown times.
When called to troubleshoot hot water shortages or designing a system you can use this formula as a quick reference to see if the system is at least in the ballpark.
I hope this will be usefull to someone out there.