Hospital steam loads (non-heating)

[Ling2006]

Hi Guys,

I have a project that I need to estimate basic non-heating steam loads for a hospital. Does anybody knows any rules of thumb? Such as: How many gal/day/person domestic hot water is required, How much steam for sterilization is required, and how much steam for kitchen is required?

I only need a rough estimate and don't have the time to go dig. I'd really appreciate it if anybody can give me a hand. Thank you so much.

 

[stanlsimon]

If you can get the numbers of meals prepared by the kitchen then you can estimate the kitchen hot water demand. The ASPE manual or a water heater rep could help you. What sized dishwasher are they figuring?

As far as the sterilizers you have to talk to the manufacturers, when they first turn on they use a lot of steam. Once they warm up they hardly draw anything. Lots of places are going to electric sterilizers. You can estimate based on cubic foot of sterilizer. Call Amsco, Steris, or whatever they call themselves now.

The big bathtubs can draw a lot of water, especially if they do back to back baths. The nurses like to give everybody a bath on the same day.

Laundry can be a huge demand. You need to know how many washers and how big they are.

Some hospitals have equipment washers for wheelchairs,beds and things. It's like an overgrown dishwasher.

In general when sizing a boiler in northern climates you have to have full redundancy, ie. an extra boiler in case one breaks.

If you really need a crude number my ASPE book says 300 hospital hot fixture units will give an instantaneous demand of 55 gpm, the curve is flat from there, so if you can slap together a fixture unit number, use the same ratio.

Sincerely,
slsimon

 

[quark]

Good points by Stan on diversity. Here are some typical values for a rough feeling (from Spirax Sarco).

Bed pan sterilizer - 3lb/hr
Dressing sterilizers - 7lb/hr
Instrument sterilizer - 3lb/hr
10gal water sterilizer - 6lb/hr
Double disinfecting ovens(per 10cu.ft) - 29lb/hr
Bain Marie (per 2.5sq.ft) - 13lb/hr
10gal steam kettle - 13lb/hr
Dish washer (per 20cu.ft) - 29lb/hr

Maximum pressure is 40psig.

Regards,