Based on the CIBSE CP1 2020 / Danish Code of Practice DS 439

Owned by Kristof Smits
Last updated: Sept 03, 2024 by Nathan Pieters
1 min read

Link

https://www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IMrmGQAT

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

Since the standard does not provide

  • design flows for individual tapping points

  • or a formula to apply diversity on the total DHW flow within one dwelling

it is not possible to define tapping points using this standard,
you must specify and lock the diversified flow of each HIU manually.

Diversity formula

With this calculation method, the diversity factor decreases according to the formula (2qm + Θ(Σqf-2qm) + Asqrt(qm*Θ)sqrt(Σqf-2qm))/Σqf, in which Σqf = T = the sum of the diversified HIU flows.

This formula only applies when 0.2 <= T. It is important to note that calculation is applicable for T expressed in liter per seconds. We assume A=3.1; Θ = 0.015; qm=0.1

Applies diversity

inside the dwelling
outside the dwelling

Requires recalculation of DHW flows?

No.

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