The effect of hot water use patterns on heating load and demand shifting opportunities

Heating loads for modern houses are lower than older houses with a larger proportion used to service domestic hot water (DHW). Electric heating systems, e.g. air source heat pumps (ASHP) and underfloor heating, offer load shifting possibilities with solar thermal DHW systems providing further opportunities. Other dynamic effects such as heat loss from water tank and stochastic demand need to be considered too. Hence integrated dynamic simulation is adopted to look at building thermal interactions with explicit plant representation and linked network mass flow and power flow solutions. Stochastic DHW use patterns characteristic of the UK are investigated. Different time controlled heating profiles are simulated to investigate demand shifting. Findings show user behaviour strongly influences water heating requirements, solar DHW system effectiveness and consequentially load shifting potential.