One of the countermeasures required against global warming is the implementation of effective energy saving solutions in the existing building stock, and Energy Service Companies (ESCOs) have emerged as a driving force to address this need. One of the features of the services offered by ESCOs is the guarantee of energy conservation, which needs to be accurately quantified to verify and improve the actual effectiveness and reliability of the implemented solutions. However, while past studies on the accuracy of baseline models have mainly focused on entire buildings, there is little knowledge on the accuracy of baselines calculated through energy conservation methods. Therefore, in this study, we verified the accuracy of baseline results calculated with each of the energy conservation methods, in comparison to the ASHRAE model, which can take into account the effects of the interim period, and a simple temperature correction model proposed by the authors.

The urgency of reducing CO₂ emissions is increasing, and there is a strong demand for methods to reduce energy consumption in existing buildings, especially new energy-saving methods that are easy to apply to air conditioning, water supply, and drainage equipment in existing buildings. Variable water volume control used in air conditioning pumps is widely adopted as an energy saving method. However, because it is difficult to guarantee the flow rate to various places, the differential pressure that is supplied is not reduced appropriately, and there are many cases where there is significant room for energy saving. Using an air handling unit as an example, we first examined a differential pressure reduction method for variable water volume control. Next, the effect of reducing the differential pressure on the capacity of the air conditioner was examined. Then, the energy saving effect by reducing the differential pressure of the air handling unit was examined. We also examined the probability that the maximum load on the air conditioner would occur. Then, we devised a control method that realizes this differential pressure reduction method in an existing building by changing the operation without modifying the equipment. To confirm the effectiveness of this control method, we compared the result with that of the existing contorole method in that building and confirmed the energy saving effect. In addition, the effect of increasing the temperature difference by reducing the differential pressure and the points to be noted in this control method are described. Based on this research, it is expected that energy saving by reducing the differential pressure of pumps of the air conditioning, water supply, and drainage equipment of existing buildings will lead to a greater reduction in domestic energy consumption.

In this study, we propose an appropriate system design and operation control method for air conditioning systems based on the realized indoor environment and energy performance considering the sharing of outdoor and room air load processing. First, we formulate an operation / control model for a dual-coil air conditioner. Next, we set up air conditioning systems with four types of outdoor air handling mechanisms for an office building. By simulating the indoor thermal environment and energy consumption for the design conditions and temperature of the seasonal air supply, we determined the system design and control parameters that satisfy the requirements for thermal comfort and energy saving performance. We also verified the energy savings when incorporating CO₂ concentration control, and the increase in energy consumption when the amount of introduced outdoor air increased due to an increase in its outdoor air CO₂ concentration

In this study, a hybrid drainage system and extensions of the existing buildings, which is adaptable to changes processes, is proposed, and its performance is evaluated to derive the water spaces due to conversion or renewal knowledge necessary for planning and design. In the previous reports ^1)-3), the “above-ceiling new drainage system that combines a force-feed drainage system with a gravity drainage horizontal pipe system, and the “system using existing horizontal fixture branches” were examined by evaluating their drainage performance, and their effectiveness was verified. In this report, a “compatible on the slab drainage system” is proposed for office buildings, which uses a force-feed pump unit and small-diameter horizontal fixture branches for draining wastewater from water spaces that need installation according to the intended use of the spaces provided in the buildings. Some variations of the drainage system are assumed, and its drainage performance is evaluated the gather basic data for the design of the drainage system.