In this study, the effect of window-to-wall ratio of a residential building is evaluated for different internal volumes of a by lumped capacitance approach. The computations are carried out for ...different window-to-wall ratios varying from 0% to 100%, internal volumes (namely, 45m 3 , 75m 3 and 105m 3 ) and insulation material thicknesses varying from 10mm to 30mm. The influence of the considered parameters on the indoor temperature of the room having a double-pane window is evaluated together with time lag and decrement factor. Computed results show that the window-towall ratio has a very significant effect on the considered parameters. Time lag increases and decrement factor decreases with the increase in insulation layer and indoor volume. However, the most significant parameter is window-to-wall ratio. As the window-to-wall ratio increases, time lag decreases and decrement factor increases considerably. The minimum decrement factor is obtained as 0.05 for 105 m 3 indoor volume and 0% window-to-wall ratio whereas the maximum decrement factor is observed 0.98 for the 100% window-to-wall ratio. The effect of insulation layer thickness on the considered parameters is more profound particularly for low window-to-wall ratio values.
An innovative control strategy for a naturally ventilated (NV) swine finishing building was evaluated. Extensive monitoring of an existing NV-controlled swine finishing building indicated that the ...building temperature control was +/-3 degrees C of set-point for less than 50% of the time, with 20% of the time greater than +/-6 degrees C. Based on the experience gained from this monitoring, the building was modified to accommodate testing and development of a new NV control logic. Using the improved NV control logic, the building temperature was +/-2 degrees C of the set-point for 91% of the time, and, +/-3 degrees C for 97% of the time for a wide range of cold and mild weather conditions with no supplemental heater use. A routine using inside relative humidity feedback was used to preserve indoor air quality levels through a series of purging routines.
The object of paper is analysis of natural ventilation system in central greenhouse of Botanical garden in Kosice. The greenhouse was refurbished in 2015. The existing greenhouse covering from glass ...panels was replaced for polycarbonate panels. The ventilation system of central greenhouse is natural and there are used openings in covering (wall, roof). It is combination of thermally and wind driven ventilation. The main aim of contribution is to analyse different modes of natural ventilation during summer period mainly. The important factors that influence efficiency of natural ventilation in greenhouse are location and area of openings, temperature stratification in greenhouse, solar radiation level, wind speed and direction too. If the greenhouse is ventilated naturally only through external windows (roof windows are closed) the efficiency of ventilation is very poor. The defined modes of natural ventilation search the right location and size of opened windows in order to achieve the most efficiency ventilation of indoor environment. For this purpose the progressive dynamic simulation tool DesignBuilder is used where the geometrical and specific calculated model of whole central greenhouse was created.
This paper proposes an implementation of advanced heating feed-forward control system for multistorey buildings based on indoor air temperature inverse dynamics model. The suggested model structure ...enables real-time assessment of the impact of unmeasurable perturbing factors on indoor air temperature, along with distinguishing between fast and slow processes occurring within the system. The paper also contains the actual results obtained by deployment of the suggested heating control system in the academic building of South Ural State University. The results obtained demonstrate the reducing of overall energy consumption by building heating system, at the same time increasing the comfort level of the building.
The paper presents a qualitative effect of external thermal mass, night ventilation flow on cooling load reduction and indoor air temperature fluctuation at nighttime using thermal mass and night ...ventilation. A simple residential building model with air-conditioning at daytime and natural or mechanical ventilation at nighttime is chosen to obtain the hourly variation of cooling load at daytime and indoor air temperature at nighttime. It is noted that the temperature distribution of thermal mass material governed by a one-dimensional non-steady heat conduction equation is considered in the paper. The dependence of the cooling load and indoor air temperature at nighttime on the thermal properties of thermal mass, night ventilation flow is further validated. Our results show that only appropriate amount of thermal mass together with suitable outdoor climates and suitable night ventilation flow will benefit most. The present work provides guidance for designing thermal mass and night ventilation.
The indoor air temperature of greenhouse is an important parameter in environmental monitoring. Existing research on it has many, and the mathematical models have been made. But the obtained models ...do not apply to the northern areas features of dry and cold. On the basis of previous studies, the indoor air temperature model of greenhouse will be re-modeling by using the regression analysis method in this paper. Analysis each convection heat transfer coefficient of the model and re-established them. In the case of known the outdoor weather conditions, the solution of the indoor temperature will be implemented by using the computer programming. And the data of a period is selected randomly from the observational data to validate the model is feasible and applied.
This paper established building inner wall heat balance equation and indoor air heat balance equation for some typical rooms in Harbin using floor radiant heating and radiator convection heating. ...Reaction coefficient method was chosen to calculate the unsteady state heat conduction of the wall, Gauss Jordan elimination method was adopted to solve equation set. The calculation programming was based on the theories above. This study compared the indoor air temperature in different typical rooms under the different heating time of intermittent heating. This study drew a series of curves depicted the indoor air fluctuation. The result showed that the room thermal stability of radiant heating method was better than that of convection heating method.
The purpose of this paper is to clarify the following two points. First point is the indoor air temperature and humidity fluctuation under an optimal operation of heat source system. Second is the ...effect of the system composition (heat source equipment capacity ratio) on the optimization results. Method for the optimization is applied to the hybrid energy source system with thermal storage tank of a middle scale office building on a certain summer day. The results are as follows : 1) the suitable change of the room temperature is calculated automatically by optimization process, so there is possibility of realizing effective energy conservation etc. by more active control of the temperature, 2) the relation between heat source equipment capacity and building heat load influences its suitable ratio, and the ratio influences the achievement degree of the optimal operation effect considerably. 3) according to a trial calculation, it is surmised that the system with a few heat source equipment using various energy is advantageous for pursuing energy conservation etc.
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