Maintenance for rooftop packaged air conditioners (RTUs) is a rare preventative practice. Generally, service calls are limited to emergency response for major system failures that impact occupant comfort. Even in the case of equipment maintained under service contracts, technicians will only detect severe and obvious faults since their procedures typically only involve routine qualitative asses...

Designers can expect environmental demands to continue to drive the need for advanced motor control techniques that produce energy efficient air conditioners, washing machines and other home appliances. Until now, sophisticated motor control solutions have only been available from proprietary sources. However, the implementation of advanced, cost-effective motor control algorithms is now a real...

During a study on the quality of the indoor environment, Acanthamoeba spp. were detected in 20 out of 87 dust samples collected from air-conditioners installed in a four-story campus building located in Kuala Lumpur, Malaysia. Twenty-one cloned Acanthamoeba isolates designated as IMU1 to IMU21 were established from the positive primary cultures. Five species were identified from the 16 isolates...

One of basic principles in designing treatment environments is to design air conditioning/ventilation system proportionate to environment. Essentially, appropriate air conditioner in treatment spaces must bear the following capabilities: providing healthy and clean air, reducing the concentration of pollutants produced in the atmosphere, emission of pollutants and impeding their spread in exter...

introduction one of the limitations of tissue conditioners (tc) is gradual hardening of the material in a short time period after insertion in the mouth, due to the loss of their viscoelastic properties. the aim of this study was to determine the softness of two different tissue conditioners with and without the monopoly coating. methods and materials in this experimental study, acropars and vi...

Simulation models for unitary air conditioners and heat pumps usually can not provide accurate predictions in the case of two-phase refrigerant entering the compressor or fixed-area expansion device. This paper focuses on improving modeling methods in these situations. The study utilized extensive laboratory tests and detailed modeling of two unitary air conditioners, one using R-410A and the o...

In this paper, the simulated performance of a number of differentiated services traffic conditioners is studied under a range of synthetic traffic conditions. The traffic conditioners are compared using two performance measures which are defined and justified in the paper. In the initial simulation the traffic conditioner performance differed in one measure but not the other. Further experiment...