Validation of Non-residential Cold and Hot Water Demand Model Assumptions

Abstract

Existing guidelines related to the water demand of non-residential buildings are outdated and do not cover hot water demand for the appropriate selection of hot water devices. Moreover, they generally overestimate peak demand values required for the design of an efficient and reliable water installation. Recently, a procedure was developed based on the end-use model SIMDEUM to derive design rules for peak demand values of both cold and hot water during various time steps for several types and sizes of non-residential buildings, i.e. offices, hotels and nursing homes. In this paper, the assumptions of building standardisation, on which the design rules are based, are validated. This was done with measurements of cold and hot water demands on a per second base and with surveys. The good correlation between the simulated water demand patterns and the measured patterns indicates that the basis of the design rules, the SIMDEUM simulated standardised buildings, is solid. Surveys were held to investigate whether the construction of the standardised buildings based on the dominant variable corresponds with practice. Surveys show that it is difficult to find relations to equip the standardised buildings with users and appliances. However, the validation proves that with a proper estimation of the number of users and appliances in only the dominant functional room of the standardised buildings, SIMDEUM renders a realistic cold and hot water diurnal demand pattern. Therefore, the new design rules based on these standardised buildings lead to reliable and improved designs of building installations and water heater capacity, resulting in more hygienic and economical installations.