Convention 6.06 - HWS Efficiencies and Storage Losses
Posted by Mike Gordon on 22 July 2015 11:04 AM


The presence of storage/losses MUST be entered for all storage systems and this should be done where possible by entering the losses (in MJ/month) in preference to the volume and insulation type and thickness. The source information (such as manufacturer’s data) and/or calculation must be included in site notes.

Where losses cannot be established then the volume and insulation details should be entered.

Where the volume cannot be readily established via external visual inspection and/or paperwork it should be estimated as follows: the external dimensions of the unit will be used as if the storage vessel completely fills the unit with no deduction for insulation thickness.

Where the insulation type can not be readily established via survey and/or paperwork it should be assumed to be uninsulated.

Where details of the HWS are unavailable or there is no system then the HWS shall be entered as an ‘instantaneous system’ with no storage with a seasonal efficiency of 0.5 (i.e. 50%). Where the fuel type can be readily determined then the appropriate fuel type must be entered otherwise ‘grid electric’ should be assumed.