This paper analyzes water hammer caused by a check valve by using a numerical solution with the characteristics method. A comparison is made on the relationship among the experimental results (Ref. Part 1), actual surveyed results and calculated results. The results are summarized below; 1) The characteristics of a check valve closed by spring force depend on time. On the other hand, those of a check valve closed by gravity depend on the flow velocity, and the check valve is closed suddenly after a counter current. 2) The closing time from the point of shut off of electricity to the onset of pressure rising (Pt.C) depends on the start time of the counter current, and the time from Pt.C to the point of the first peak depends on the wavespeed. 3) The maximum pressure rising rate depends on not only the closing time but also the magnitude of the counter current and the pattern of flow velocity. 4) Some differences are found between the actual survey results and the experimental results, and they seem to be caused by the effects of total pipe length and characteristics of pump. 5) The calculated pressure waves agree with the actual survey results and the experimental results.

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Based on the experimental method introduced in the Part 1 of this study, the heat transfer through a window into a room is separated into the components of convection, radiation and ventilation, and solar shading effects are examined in this paper. The influences of the thickness of the air layer and the width of the slits caused on the componental heat transfer of a window with a roll curtain are investigated. In addition, the mechanism of heat transfer and the difference of it are discussed for 5 kinds of windows with different air-tight conditions. The results are concluded as follows: 1) Using the experimental value of windows in 12 kinds with 10, 30, 65mm thick air layer and 0 (sealed air layer), 5, 12.5, 20mm wide slit respectively, the isoplethes of air inflow ratio and total inflow ratio with the parameters of thickness of air layer and the width of the slits are obtained. 2) From the infrared thermogram of windows in 5 kinds with different air-tight conditions in the air layer between the window glass and the roll curtain and the temperature profile of the cross section of the window, the ventilation by the heat convection of the air layer is made clear qualitatively. 3) From a viewpoint of solar shading, the type of window with slits in the right and left sides of a roll curtain is more effective than that with slits in the upper and lower sides of the roll curtain.

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In the previous paper, the authors proposed to clarify the characteristics of each part by dividing the stack into five regions based on the pressure distribution inside the pipe being obtained through the test on a single stack system of 100mm using JIS DT type fitting loaded with steady drain from one floor, and reported that the three regions are considered as the resistance of air flow in the network. In this paper, the authors conduct the remaining two regions which are region 4 (suction) and region 2 (resistance). After describing the results of the stack of 75mm and 125mm, the authors discuss a law of similarity in every regions including region 2 which had been reported in previous paper. Based on the above, authors simulated the distribution of the pressure inside the single stack through theoretical calculation by using a method to balance the sum of four resistances with the suction of region (4).

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Heating requirements at a preheating period in the early morning could be estimated using the dynamic load calculation program such as HASP. However, it has been found that the program resulted in too large heating capacity due to neglecting the followings; 1) Operation of heating apparatus at full capacity during preheating period. 2) Thermal synthesized effect between perimeter and interior zones during the off-operation. 3) Increased capacity of heating coil while existing larger temperature difference between air and water than the designed value. 4) Allowable room temperature shift from the setpoint at the beginning of occupation. Authors gave those corrected algorithm to HASP load calculation program in the first place. Then, nine pre-studied factors were given together with the levels in values and combinations of each factor-level was decided by allocating L-81 orthogonal table in the experimental design method. Results of experiments with the load calculation program were analyzed statistically and significant factors on preheating capacity were chosen using analysis of variance. Two kinds of factorial effects were tabulated. One is the preheating capacity for unit area and the other is the preheating loadfactor for both perimeter and interior zones. The proposed method which use steady state calculation results and the prepared tables by authors will make it possible to estimate the preheating capacity easily and precisely.

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In this paper, the characteristics of low temperature panel heating is investigated by computer smulation. The low temperature panel heating system is designed for a standard residential house, and the PMV and energy consumption are simulated hour by hour through a heating season. The effects of various parameters, daily heating period, control method, human position and set back of supply hot water temperature, are analyzed. Comfort and required energy are compared between the panel heating system and convecter heating system. Merits of the panel heating system and important parameters effected on this system are made clear.

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This paper describes approximation methods of the thermal characteristic functions using the typical system reduction techniques. It is shown that the approximation problem on the thermal characteristic function leads to the choice of time moments and Markov parameters of which first ones dominate an integration of the exponent terms and an initial value in the time domain. Numerical experiments prove that the reduced model obtained by the present methods, which retain both time moments and Markov parameters, has a satisfactry approximation.

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This paper presents a numerical prediction method for unsteady state thermal environments in a heated room, including calculations of the distribution of thermal radiation and of comfort indices, and also presents the results of the application of this method to a heated room with either floor panel heating (FPH) or forced convective heating (FCH) to illustrate the characteristics of both systems. For a steady state condition, a prediction method and the calculated results of the heating systems were already shown by the authors in the previous paper. In this paper, the calculation of unsteady state thermal conduction through walls is combined to the prediction method using the backward implicit finite difference scheme. Then, the time dependent variables for a thermal environment after initiation and termination of heating are calculated and compared for both systems. As in the previous paper, the calculations are conducted on a room model shown in Fig. 1. The air temperature and air velocity are assumed to be uniform, and appropriate values are employed as known values for the air velocity and convective heat transfer coefficients. For FPH, a constant surface temperature or a constant heat flux is assumed for the heated floor. For FCH, a constant heat supply is assumed. One of the results showed that, for the case of the same amount of heat supply, the room air temperature of FCH rose a little faster than that of FPH, but the mean radiant temperature of FPH rose much faster than that of FCH, and the thermal comfort indices (PMV and SET^*) of FPH rose faster than that of FCH. For after termination of heating, both systems showed little difference. These tendencies are dependent on the various conditions assumed, so a general conclusion on both systems can not be derived from only this case study. The characteristics of heating systems can be shown more clearly by systematic analysis for the various conditions with this prediction method developed in this paper.

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Pick-up load factor defined as the ratio of pick-up load to the steady-state heating load, that can be used in design heating load calculation, was derived from the convolution of impulse response of room air temperature and space heating load as a rectangular pulse. Design heating load calculation for equipment sizing is usually based on the steady-state heat transmission loss through building envelopes. This is because the simplicity is a very important feature required in design calculations. The steady-state heating load itself can not involve the additional heat for raising room air temperature to the specified temperature; design engineers usually estimate the amount of pick-up load, multiplying the steady-state heating load by a certain factor, or adding a certain amount of heat to the steady-state heating load. Since the values of the multiplying factor and the additional heat being used in practice have empirically been determined for long years, they can not rationally reflect the effects of the length of pick-up period, the heat capacity and insulation of walls on pick-up load. In order to include these features in design heating load calculations, we have theoretically developed a formula of pick-up load factor. Pick-up load factor is expressed as a function of not only overall heat loss coefficient of a room, the lengths of pick-up period and total heating period, but also two unique variables: effective heat capacity of a room and its related thermal conductance toward room air. Effective heat capacity and its related thermal conductance can numerically be obtained from the constants appeared in indicial response of walls. To determine the constants in the formula of pick-up load factor, it is required to solve a quadratic equation involving overall heat transmission coefficient, effective heat capacity and its related thermal conductance. The calculation of pick-up load factor is, therefore, considerably time-consuming. To reduce the original formula to the one which does not require the solution of a quadratic equation, and to estimate the values of the two unique variables (effective heat capacity and related thermal conductance) with almost the same amount of calculation of overall heat transmission coefficient, the following assumptions were made: 1) effective heat capacity is equivalent to the total heat capacity of walls weighted by the thermal resistances inside and outside the concrete layers; 2) related thermal conductance is equivalent to the conductance from the inside surface of the concrete layer to room air; 3) the effect of the heat capacity of room air and internal furnishings is negligible. These assumptions provided a formula for calculating pick-up load factor much simpler than the original one. The equivalent values of the two variables (effective heat capacity and its related thermal conductance) were in good agreement with the ones obtained from the constants appeared in the indicial response. The values of pick-up load factor calculated from the simple formula also agreed with those from the original one. Parametric analyses were made to reveal the characteristics of the simple formula. The results showed the followings. The values of pick-up load factor for a room of concrete structure with 1 hour of pick-up period and 9 hours of total heating period, turned out to be 2.2〜2.4. This implies that pick-up load can be 2.2〜2.4 times larger than the steady-state heating load. The reduction of 10〜15% in pick-up load can be expected from 1〜2 hours longer pick-up period. Parametric analysis of the pick-up load factor suggests that pick-up load of a room with concrete structure having inside insulation becomes larger than that of a room having outside insulation. Validation of the pick-up loads obtained from the proposed method against those from a computer-based detailed simulation method will be required in a future study.

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Based on the synthetic investigation on room environment and building equipment of office buildings located in four cities (Fukuoka, Kumamoto, Kagoshima, Oita) in Kyushu district conducted in 1983, the results of analysis on the capacity of plumbing equipment are described in this paper. The contents are as follows. 1) The capacity of equipments was more closely related to the total floor area than to the number of occupants. Especially, the number of sanitary fixtures was closely related to the total floor area. 2) About the capacity of water supply installation of the office buildings in the four cities, the capacity of receiver tank and elevated tank showed the highest value in the office buildings in Fukuoka city. 3) Materials of the feed pipe and receiver tank have been almost changed to polyvinyl-chloride-lining steel pipe or FRP (fibre glass reinforced plastic) since 1975.

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