Plate Heat Exchangers in Residential Buildings: How to Avoid Oversizing

CIBSE Technical Symposium, DeMontfort University, Leicester UK
6th and 7th September 2011

The mechanical services engineer at some stage of design has to deal with the estimation of domestic hot water loads and correlated design temperatures and flow rates. Traditionally semi empirical rules have been used to assess plausible hot water loads leading to the installation of flat - localised hot water cylinders. These loads are proving to be ineffective in designing a system which includes modern highly efficient devices such as plate heat exchangers.
Common standards lead to high flow rates, pipeline oversize and do not consider energy saving solutions such as variable speed pumping. The design approach needs to be revised according to new targets such as carbon emissions reduction and this dictates a revision of the common calculations methods and statistical data used. We will analyse a different approach using north European standards as point of reference.