Browse Topic: Air conditioning
This SAE Aerospace Recommended Practice (ARP) contains guidelines and recommendations for subsonic airplane air conditioning systems and components, including requirements, design philosophy, testing, and ambient conditions. The airplane air conditioning system comprises that arrangement of equipment, controls, and indicators that supply and distribute air to the occupied compartments for ventilation, pressurization, and temperature and moisture control. The principal features of the system are: a A supply of outside air with independent control valve(s). b A means for heating. c A means for cooling (air or vapor cycle units and heat exchangers). d A means for removing excess moisture from the air supply. e A ventilation subsystem. f A temperature control subsystem. g A pressure control subsystem. Other system components for treating cabin air, such as filtration and humidification, are included, as are the ancillary functions of equipment cooling and cargo compartment conditioning
This ARP provides the definition of terms commonly used in aircraft environmental control system (ECS) design and analysis. Many of the terms may be used as guidelines for establishing standard ECS nomenclature. Some general thermodynamic terms are included that are frequently used in ECS analysis, but this document is not meant to be an inclusive list of such terms
This Aerospace Information Report (AIR) outlines the design considerations and criteria for the control of water carryover from the environmental control system (ECS) with respect to causes and indicated corrective or preventative action. In addition, condensation on structure will be reviewed with possible preventative action described
Energy efficiency in both internal combustion engine (ICE) and electric vehicles (EV) is a strategic advantage of automotive companies. It provides a better user experience that emanates amongst others from the reduction in operation expenses, particularly critical for fleets, and the increase in range. This is especially important in EVs where customers may experience range anxiety. The energetical impact of using the air conditioning system in vehicles is not negligible with power consumptions in the range of kilowatts, even with a stopped vehicle. This becomes particularly important in areas with high temperature and humidity levels where the usage of the air conditioning systems becomes safety factor. In such areas, drivers are effectively forced to use the air conditioning system continuously. Hence, the air conditioning system becomes an ideal choice to deploy control strategies for optimized energy usage. In this paper, we propose and implement a control strategy that allows a
In automotive air conditioning systems, compressor is used to convert low pressure low temperature refrigerant into high pressure high temperature refrigerant. Various types of compressors like swash plate, rotary vane, scroll etc. are widely used in the automotive industry for air conditioning applications. In rotary vane compressors, thermal protector is used as a safety device, designed to prevent the compressor from overheating during refrigerant compression process. When the discharge temperature exceeds the preset limit of thermal protector, the thermal protector will activate and stop the electrical supply to compressor clutch to stop the compressor operation thereby preventing potential damage to air conditioning system, engine, and other nearby parts of the vehicle. This technical paper explores the various real-world scenarios for a hot country like India, which may result into higher discharge temperatures of compressor resulting into activation of thermal protector. The
The purpose of air conditioning (AC) duct packing is multifaceted, serving to prevent condensation, eliminate rattle noise, and provide thermal insulation. A critical aspect of duct packing is its adhesive quality, which is essential for maintaining the longevity and effectiveness of the packing's functions. Indeed, the challenge of achieving adequate adhesivity on AC ducting parts is significant due to the harsh operating conditions to which these components are subjected. The high temperatures and presence of condensation within the AC system can severely compromise the adhesive's ability to maintain a strong bond. Moreover, the materials used for these parts, such as HDPE, often have low surface energy, which further hinders the formation of a durable adhesive bond. The failure of the adhesive under these conditions can lead to delamination of the duct packing, which can result in customer inconvenience due to rattling noises, potential electrical failures if condensed water
During design development phases, automotive components undergo a strict validation process aiming to demonstrate requested levels of performance and durability. In some cases, specific developments encounter a major blocking point : decoupling systems responsible for optimal acoustic comfort performances. On the one hand, damping rubbers need to be soft to comply with noise, vibration & harshness criteria. However, softness would provoke such high amplitudes during vibration endurance tests that components would suffer from failures. On the other hand, stiffer rubbers, designed for durability purposes, would fail to meet noise compliance. The rubber design development goes through a double-faced dilemma : design with acceptable trade-off between NVH and durability, and efficient ways to develop compliant designs. This paper illustrates two case studies where different methodologies are applied to validate decoupling systems from both acoustic and reliability perspectives. The goal was
Enriched ventilation and driver assistance systems which plays vital role in human thermal comfort and safety, are now necessities for the whole automotive sector. For faster cabin thermal comfort, air circulation around occupant’s body reveals higher cabin comfort index. In India natural and forced ventilation system is predominantly used in commercial vehicles as an economical solution for achieving interim cabin comfort over air conditioning system. Presently used forced ventilation system consist of electrically driven blower motor to remove stale air around human body which is adding alternator load and thus affects fuel economy. Remarkably, 22% of such auxiliary electrical load is taken by electrical components from engine generated power. In order to enhance cabin thermal comfort and conceivably reduce power usage, an effective air flow control system is need of hour. In the proposed new technology, the ORVM (Outside Rear View Mirror) based air cooling technique is used for
The complexities of electric-vehicle HVAC require new sensing solutions. An expert at TDK explains. A common criticism of electric vehicles (EVs) is that extremes of heat and cold adversely affect their performance, particularly range. OEMs have been aware of the issue and have innovated and iterated technologies to solve it. EVs increasingly are being engineered with sophisticated heating, cooling and ventilation (HVAC) systems based on some of the most advanced and robust sensors and actuators available. These systems mitigate against the effects of thermal extremes that, admittedly, still challenge IC-engine vehicles on an infrequent basis. But there are tradeoffs. The ICE vehicle's HVAC is a relatively simple affair involving air cooling, a coolant (water ethylene glycol, or WEG), heaters, and heat exchangers (including air conditioners). HVAC systems for EVs by necessity are far more complex. Understanding the details is important to designing an effective system
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