×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

ASPE Hot water Demand for Fixtures

ASPE Hot water Demand for Fixtures

ASPE Hot water Demand for Fixtures

(OP)
I have been in the engineering business for 30 years. Specifically, plumbing. In the ASPE Data Book (pick any year), the hot water demand for showers in Gymnasiums, Industrial Plants, Schools and YMCA's has been declared 225 GPH. When will this number be corrected? IPC limits the flow for showers to 2.5 GPM at 80 PSI. 2.5 x 60 = 150 GPH.
Where did 225 come from? Who uses this number in their water heater calculations?  

RE: ASPE Hot water Demand for Fixtures

The numbers come from old information when showers were ~4gpm - which was not too long ago.  

I use a much lower number which takes into account that you will not be running the shower for an entire hour and only a part of the water is hot.  

But I do use the demand factor and the storage capacity factor that ASPE gives.  They give pretty good numbers which accounts for diversity among the total number of fixtures and the facility needs.

RE: ASPE Hot water Demand for Fixtures

(OP)
I trim the load myself, just as you do. It makes plenty of sense to base it on an actual flow rate x an assumed duration. One problem which causes us to debate with high intelligence, low common sense, plan reviewers in a government like setting is they stipulate that our calc's must adhere to ASPE. When I indicate a shower at say, 40 GPH in lieu of 225, I find myself having to (once again) substantiate my decision. They usually accept it. But, time arguing is still time, which = money. I say, shame on ASPE for not addressing this factor a long time ago. I just received my 2005-06 Data book and it's still in there.

RE: ASPE Hot water Demand for Fixtures

You are in a "long" line waiting for ASPE to update some of their information.

They are waiting for somebody to give them money to do the research since they cannot seem to come up with the money on their own.

IMHO they need to fix Hunter's curve before they do anything else.  That information dates back to the 50's if I am not mistaken.

RE: ASPE Hot water Demand for Fixtures

(OP)
Well, I will keep doing it how I've been doing it. One day, the ASPE experts will see that a person could actually drown under a 4 gpm shower head if they stayed in there for a solid hour. If it's one of my systems though, the last 50 minutes will be a very chilling experience.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources