2012 OBC Part 7 - Table A 7.6.3.1

Started by newbieeng, August 22, 2014, 03:41:32 PM

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newbieeng

Can anyone explain how the values in the 'total' column in Table A-7.6.3.1 are derived? or what they represent?

Thank you.


Admin

QuoteCan anyone explain how the values in the 'total' column in Table A-7.6.3.1 are derived? or what they represent?

Part 7 has to do with plumbing, and I think you're talking about Table 7.6.3.2A.

The total is just that, the total fixture units.  You always lose pressure when you use hot water as it relies on the supply (cold) water pressure.

Use this formula,

qet = qnl + 0.015 (qn - qnl  ) + 0.17 ( qn - qnl  )1/2

newbieeng

Is there a source or some website I can site when I show this to my manager? Or is this something you have derived using data samples?

newbieeng

Btw, the formula doesn't work or I must be using it wrong.

Admin

Sorry, my phone didn't copy the sigma symbol.

newbieeng

I still cannot work out the total column in table. Also, is there somewhere I can find this and read up on it ? Thank you for your help so far.

Admin

I really don't know much about plumbing.  You can look at this water pipe sizing document - Here

QuoteThe information on sizing the potable water (cold & hot water) is defined in the American Society of Heating, Refrigeration and Air Conditioning Engineers "ASHRAE 1991" Applications Handbook, Uniform Plumbing Code (UPC) and American Society of Plumbing Engineers (ASPE) handbooks. All these criterions focus on the use of probability theory to compensate for unknowns. The required flow rates are defined based on "Fixture Unit Count" method, which takes into consideration people use factors, people socio-economic factors, facility types, fixture types and host of other factors. This method permits the tabulation of total fixture units by summing individual fixture demands. The water demand can than be estimated from a fixture unit-water demand curve.

The total FU is determined by using Probability Theory.  Good luck with that!  ;D