This paper provides a review on the fouling mechanism and its effect onto the performance of finned tube heat exchangers in HVAC systems. Fouling tends to degrade the performance of heat exchangers by decreasing the heat transfer coefficient and increasing the air-side pressure drop across the heat exchangers. Air side fouling depends on a number of factors on the air side, including type and c...

Fin-and-tube heat exchangers have been extensively used in many fields, especially heat, ventilation, air-conditioning, and refrigeration systems. In the case of operation a fin-and-tube exchanger as an air cooler, frost formation is important effect that should be taken into account. The accumulation process undesirable since it deteriorates transfer due to insulation layer well causing excess...

BACKGROUND Patient warming has become a standard of care for the prevention of unintentional hypothermia based on benefits established in general surgery. However, these benefits may not fully translate to contamination-sensitive surgery (i.e., implants), because patient warming devices release excess heat that may disrupt the intended ceiling-to-floor ventilation airflows and expose the surgic...

Heating, ventilation, air conditioning and refrigeration (HVAC&R) systems provide physical environment comfort for the occupants at a possible expense of large amount energy consumption [...]

The paper aims at studying different strategies for the optimal operation of Breathing Walls during summer. investigation is carried out by performing dynamic simulations on a case study. To this purpose, transient Finite-Difference numerical model Wall components, previously developed in Matlab and validated Authors, coupled with TRNSYS. study consists an office room located Milan, Italy, prov...

With the increasing popularity of renewable energy sources and globally electricity demand, task balancing intermittent supply with varying demand becomes increasingly difficult. Instead adjusting supply, improving response (DR) can be a more efficient way to optimize power balance. HVAC (heating, ventilation, air-conditioning) systems, which operate on side power-grids, have huge potential imp...

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...

Over half of the total electricity consumption is used in buildings. Air-conditioning and electric lighting are the two main resources of electricity consumption in high rise buildings. One way to reduce electricity consumption would be to limit heat gain into buildings, therefore reduce the demand for air-conditioning during hot summer months especially in hot regions. On the other hand natura...

The indoor air quality in an operating theatre affects both patient health and the well-being of the surgical team members. Health care facilities, and operating theatres in particular, require ventilation and air conditioning for thermal comfort and removal of contaminants. Although the patient undergoing surgery is given the highest priority, it is important to consider the comfort of surgica...