Infiltration has traditionally been assumed to contribute to the energy load of a building by an amount equal to the product of the infiltration flow rate and the enthalpy difference between inside and outside. Application of such a simple formula may produce an unreasonably high contribution because of heat recovery within the building envelope. Previous laboratory and simulation research has indicated that such heat transfer between the infiltrating air and walls may be substantial.
Submitted by Maria.Kapsalaki on Fri, 10/25/2013 - 18:55
Hybrid ventilation systems combine the superior properties of natural and mechanical ventilation systems to reduce energy consumption. In this study, hybrid ventilation simulations were performed for several cities in Turkey, which have different climate conditions. Matlab/Simulink was utilized to perform the simulations. The results of these simulations were compared with that of regular air conditioning units in terms of energy consumption.
The non-uniform behaviour of the air inside a room, which is important in comfort analysis, can be evaluated by zonal models. While not as fine-grained as CFD simulation, they do give useful information about temperature and moisture distributions that is not available from lumped-parameter models. Therefore, we have developed a tool, called SimSPARK, to automatically build dynamic zonal simulations of a building zone.
This work evaluates the performance of different façade solutions, comparing simulation results of glass type and (internal and/or external) solar protection, in the cities of São Paulo and Rio de Janeiro, Brazil. For the simulations, it was considered as
This paper explains how to enhance the energy performance of a chiller plant designed with chillers ofequal size or unequal size and having superior coefficient of performance (COP) at part load operation.A simulation study was carried out on an air-cooled centrifugal chiller plant serving an office building.Four design options with respect to the number and nominal capacity of chillers were investigated(OP1: 6 x 1124kW; OP2: 8 x 810kW; OP3: 4 x 1213kW + 2 x 810kW; OP4: 2 x 1350kW + 2 x 1107kW +2 x 801kW).
Total heat exchanger model based on experimental results was incorporated in the entire buildingmodel with the stay and internal generation of heat and with window opening-closing schedule, andenergy-saving effects of total heat exchangers were evaluated including regional features in Japan.Regional differences were found in the effects, and it was found that the reduction rate of heating andcooling loads was in the range of about 2 15%, and the reduction amount of heating and coolingloads was in the range of about 0.1 11 GJ.
Using a passive tracer gas technique, 1 and 2 week averages of local mean ages of air have beenestimated in an occupied detached single family house in mid-Sweden during one year. In this paperthe measurement result is compared with the result of transient simulation of ventilation using theCONTAM program. The simulation shows that the whole-house air change rate is dominated by theinfiltration due to mechanically created pressure difference as long as the outdoor temperaturedifference exceeds approx. 10 C.
A Simulation Program for Regional Energy and Environment Management (SPREEM) has beendeveloped for management throughout the life cycle from planning and design to operation of awide-area energy and environment whose core is DHC (district heating and cooling). Highoperability and easy understanding are required in SPREEM because its target users includedesigners and operations managers.SPREEM was developed as a simulation tool that executes calculation in Excel, and offers the highaccuracy required for management.
As a part of our research on energy conservation and thermal comfort of detached houses havingcentralized HVAC systems, study with numerical simulation techniques was started. The model is thehouse that has mechanical supply and exhaust ventilation systems with a centralized air duct equippedwith a sensible heat exchanger and has large return air (4 times an hour). The parameters in thesimulation are the set point temperature and outdoor air flow rate.
As a new way of air conditioning, task air conditioning (TAC) system is often used in combine withbackground air conditioning (traditional central air conditioning) system. In this research, the ComputationalFluid Dynamics (CFD) technique is used to analyze the impact on thermal environment of task zone whenthese two air conditioning systems are used together. The purpose is to find the thermal satisfactory workingconditions of the task air conditioning when the temperature of the background air conditioning is set to behigh.