HEALTH AND SANITATION 35
David Viola , IAPMO CEO
In the spirit of the sharing of unique experiences that shape the plumbing industries in our respective nations , the following article looks at IAPMO ’ s Water Efficiency and Sanitation Standard , which focuses solely on achieving safe and efficient water use in both residential and non-residential buildings . This is part two , and the next in a regular series of similar articles that will run in this magazine .
Part two
By
IAPMO
The fixture flow rates are for water-conserving plumbing fixtures and appliances , and the values may be reduced as actual fixture flow rates are being reduced .
The probability of fixture use was derived from the largest US database for residential end use of water survey . To use this spreadsheet for estimating peak water supply demand loads , enter the number of fixtures and appliances in Column [ B ] and click on the box that says Run Water Demand Calculator ( see Water Demand Calculator – Key ). The estimated demand flow will automatically be calculated in the green box . The results will be more definite than using a curve and trying to match the exact ( x , y ) ordinates on the curve with the corresponding flow rate .
In the meantime , you may download the Water Demand Calculator at http :// www . iapmo . org / water-demand-calculator and check it out . The Excel spreadsheet contains macros that will automatically flag a warning about potential viruses and corruptions when you download the file . Place your Number We all love simplicity . Simplicity saves time , reduces the margin of error , promotes broader applicability , and is userfriendly . Students today love the simplified ‘ plug and chug ’ math .
This is when you have a ready-made formula complete with the X and Y variables . All you have to do is substitute the X and Y with the right numbers and chug away at the math . Better yet , if you have the formula programmed in your graphing calculator , you just plug in the numbers and let the calculator do the chugging for you . This is what the Water Demand Calculator that was introduced in the previous article provides for plumbing system designers . In that article , readers already saw a binomial formula that was a bit complicated and would intimidate those less savvy with numbers from attempting to use . Simplicity was key when choosing an MS Excel spreadsheet as a calculator , where you only need to place your number in the assigned cell and let the calculator produce the odds .
There are four formulas programmed in the Excel spreadsheet . The calculator will select only one formula based on the numbers you place in the spreadsheet . It will then evaluate the number for each kind of fixture with its corresponding frequency of use ( the p-value ), sum up the values , and place that value within a range determined for one of the formulas . Once the formula is chosen , it chugs out the math and places the answer in the Demand Flow box within seconds . Seriously , all you have to do is place your number and you are guaranteed the winning answer .
Are you ready to place your number ? Let ’ s try this out . If you downloaded the calculator using the link provided in the previous article ( also provided at the end of this article ), then open it up and follow along . The example given in the key shows a
July 2021 Volume 27 I Number 5 www . plumbingafrica . co . za