Water-Based Heating/Cooling in Residential Buildings: Towards Optimal Heat Emission/Absorption Elements (Water-gebaseerde verwarming/koeling in residentiële gebouwen: naar optimale warmte emissie-/absorptie-elementen)
Water-Based Heating/Cooling in Residential Buildings: Towards Optimal Heat Emission/Absorption Elements
Peeters, Leen; S0039924
This dissertation describes the development of a new method for si mulating water-based heating/cooling installations in residential buildi ngs and demonstrates how such method could be used to determine optimal heat emission/absorption elements for residential buildings. The reason to develop this new simulation method was to define optimal h eat emission/absorption elements that fulfil the thermal comfort require ments in an energy efficient way. Based on a thorough state-of-the-art s tudy, the thermal comfort requirements for the specific setting of a res idential building have been defined. It is shown that 3 different zones can be distinguished; the bathroom, the bedroom and the other zones. Eac h of these zones requires different temperature settings in order to sat isfy the thermal sensation of its occupants. The width of the band of ac ceptable temperatures around this neutral temperature was determined to be 5 K, asymmetrically distributed around the neutral value. Besides this steady state thermal comfort, a potential optimal heat emit ter/absorber should further cause limited indoor temperature fluctuation s. These dynamic thermal conditions are difficult to incorporate in buil ding energy simulation software due to their dependency on the simulatio n timestep. However, by simulating with a fixed small timestep when opti mising different heat emission/absorption elements, a too high cycle fre quency of the indoor temperature can be penalised. The thermal comfort requirements define the boundary conditions a heatin g/cooling installation should fulfil. An algorithm to verify the thermal comfort requirements and the structure to model heating/cooling install ations have been embedded in an existing building energy simulation soft ware to correctly account for the building-installation interactions. Th e building simulation code used is ESP-r. The implicit plant modelling i mplementation is mainly embedded within the ESP-rs zone/building contro l level. It contains a heat emission/absorption model with idealised and more realistic controls, a structure for a distribution level and a pro duction device model with different controls and different efficiency ca lculation routines. The model for the heat emission/absorption element is based on a formula , commonly encountered in building simulation, to represent different ty pes of water-based heat emission elements. Through an extended theoretic al analysis, improvements to this formula have been proposed. This model requires a limited amount of characterising parameters. To de termine the optimal value for each of these parameters, the building sim ulation code ESP-r, extended with the implic it modelling approach, has been coupled with the optimisation tool GenOp t. This coupling allows determining the optimal heat emitter/absorber el ement for a given building model in a specific setting. Through various examples, the possibilities and limitations of this generic methodology have been demonstrated.