Based on DIN 1988-300

Owned by Kristof Smits
Last updated: Sept 05, 2024 by Igor Kovacevic
2 min read

Link

https://www.en-standard.eu/din-1988-300-codes-of-practice-for-drinking-water-installations-part-300-pipe-sizing-dvgw-code-of-practice/

Application

Domestic Hot Water

This standard calculates the diversity based on

Number of tapping points
Type of the tapping points
Total DHW flow
Diversified DHW flow
Number of dwellings

Diversity formula

With this calculation method, the diversity factor decreases according to the formula (a * (T)^b - c) / T, in which T is the sum of the design flows (for hot water) of all individual taps.

For apartments : a = 1.48, b=0.19, c=0.94

For hospitals : a = 0.75, b=0.44, c=0.18

For hotels : a = 0.70, b=0.48, c=0.13

This formula only applies when 0.2 <= T and T <= 500.

It is important to note that calculation is applicable for T expressed in liter per seconds.

apartments
hospitals

 

Applies diversity

inside the dwelling
outside the dwelling

Requires recalculation of DHW flows?

Yes. This standard assumes a DHW regime of 15°C for cold water and 60°C for hot water, resulting in a mixed temperature of 37,5°C (when both flows are equals). If the temperatures in the Hysopt model deviate from this standard regime, the design flows for cold and hot water are first recalculated (in order to achieve a mixed design flow of 37,5°C), see Step 1 : recalculation of the tapflows for more info.

Remarks

For apartments with low volume flows, there is a small “strange“ bump in the diversity graph if you apply the formula

 

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