air conditioning refrigerant r134a has value of global warming potential (gwp) 1300, which is much higher than mac directive (gwp below 150) passed in july 2006. this prompted a search for alternative refrigerant with gwp value less than 150. r1234yf is a new refrigerant which has lower gwp value of 4. effect of blower speed has been compared and flammability issue of r1234yf has been addressed...

This paper presents the development of a simulation tool based on the Matlab computational environment for building temperature performance analysis with automatic control. The simulation tool contains mathematical models for buildings, HVAC (Heating, Ventilation and Air Conditioning) systems, sensors, weather data and control algorithms. The building mathematical model is described in terms of...

Air conditioning refrigerant R134a has value of global warming potential (GWP) 1300, which is much higher than MAC Directive (GWP below 150) passed in July 2006. This prompted a search for alternative refrigerant with GWP value less than 150. R1234yf is a new refrigerant which has lower GWP value of 4. Effect of blower speed has been compared and flammability issue of R1234yf has been addre...

Air filtration is frequently recommended as a component of environmental control measures for patients with allergic respiratory disease. Residential air filtration can be provided by whole house filtration via the home's heating, ventilation, or air conditioning system, by portable room air cleaners, or a combination of the two. Appliances to filter the sleep breathing zone also have been deve...

It has great significance to estimate the schedulable capacity of air-conditioning load of public building for participating the power network regulation by forecasting the air-conditioning load accurately. A novel forecast method considering the accumulated temperature effect is proposed in this paper based on Elman neural network. Firstly, the starting and ending date for forecast considering...

In order to solve the problem of input fresh air overheating (cooling) in cold supply (heating) season severe regions, a soil source (BHE) combined with preheating conditioning system was studied net-zero energy building Shenyang. Firstly, hybrid TRNSYS-CFD simulation model based on TRNSYS and Fluent software established simulate operation indoor temperature distribution during typical day summ...

Redundancy is generally considered in the computer room air conditioners (CRACs) of data center room. The position CRAC on state and operating volume have a great influence temperature distribution. distribution will affect failure rate servers energy consumption air-conditioning system. Taking typical as an example, this paper uses numerical simulation to study on/off CRACs hot cold aisles con...

Air pre-cooling equipment is normally being employed in air-conditioning systems for pre-cooling the ambient outdoor air to enhance the air-conditioning systems performance. In this study, the potential of a passive water-to-air heat pipe based heat exchanger (HPHEX) for air pre-cooling purpose in air-conditioning systems for the high cooling load demanding regions of Iran was investigated. To ...