2.4.1 Car seat backrest
Figure 2.4.1 upholstery of a backrest.
A plastic front seat backrest is shown in Figure 2.4.1 are made of high-strength composite material, enabling design freedom on seat backrest for new premium interior styling. For example, The combined first-row composite seatbacks like Weigh almost 20% less than conventional seatbacks, reducing CO2 emissions over the life of the vehicle by an estimated 100 kilograms and Are 15% thinner than the industry’s thinnest seats, leading to 10 litters of additional interior cabin volume. The lighter weight can yield improved fuel performance for internal combustion, hybrid and all-electric vehicles; and less fuel consumption means fewer emissions of greenhouse gases. At the same time, the significantly thinner seatbacks allow designers either to provide more leg room to the second-row occupants or to shorten the overall length of the vehicle, thereby further reducing its total weight. The seatback is a technically mature system that has been fully validated for reliability, safety and comfort. Designers now have entirely new opportunities to customize and adapt seatbacks in vehicles. Since they are created with injection molding systems, the composite seatbacks allow for novel shapes and accessories to be added for the comfort of front seat occupants and the convenience of second-row passengers (Vinod, 2016).
2.4.2 Thermoelectric device
A thermoelectric device as shown in Figure 2.4.2 was used to control the temperature of the car-seat surface: the warm temperature in the summer and cold temperature in the winter. The characteristics of the thermoelectric device for the car-seat were analysed in relation to the input voltage and output temperature of the device (Bell. 2013).
Figure 2.4.2 thermoelectric cooling system
2.4.3 Compact centrifugal fan or radial fan for car seat ventilation
A fan device is show in Figure 2.4.3 which is built into a vehicle chair, and is arrange to ventilate away air that is drawn through the covering and filling of the vehicle chair, which has an electrically driven fan of radial type attached at the bottom of the chair. The fan wheel extends from the driving cover of the motoer, which extends up into the inlet of the fan. The fan is attached to a carrying means in the chair which is located on the underside of the filling and has passages for the ventilating air adjacent to the fan inlet.
Figure 2.4.3 radial fan device
2.4.4 SPA Seat Cushion
Figure 2.4.4 Backrest of an SPA seat Figure 2.4.5 Ventilated cushion of an SPA seat
Ventilated backrest from an SPA seat without massage function. The bigger cluster of holes is in the upper back area, while the lower back area has only four small holes. Another typical feature is grooves around various holes. These help to guide the flow in a desired direction.
When removing the foams from the frame, the only attachment is a rubber duct for seat ventilation. These two parts, like the upholstery, can be quickly assembled and disassembled without any special tools. The frame contains the attachment for the foams. The backrest is mounted to a plastic plate, where valves for the bolsters and massage bladders are.
2.4.5 Flexible Aluminium Foil Air Ducting
Figure 2.4.6 Flexible ducting Figure 2.4.7 Flexible Aluminium Ducting Ventilation Vent Tube
To optimize the airflow through the system, a significant factor is to understand the design of the ductwork is shown in Figure 2.4.7 and Figure 2.4.8 Even though the B-side is not strictly pipes, it can be assumed to be so, for engineering purposes. Crucial parts are the outlets, inlets and areas where the flow separates. Most literature focuses on fans with as pushing system. Throughout the system, it is not relevant if the fluid is pushed or pulled through the pipe (Cory, 2005). Included in performance enhancements, one factor is to reduce the noise. This increases the performance without compromising airflow. The noise is not the most essential part for this project, but it cannot be increased. If the noise reaches a lower level the comfort increases. An essential factor is that the noise is directly coupled with duct design. This means that a good duct can improve both airflow, and reduce the noise (Tsai, 1982).
2.4.6 Pneumatic Systems (Pneumatic Seat Control)
Figure 2.4.9 Pneumatic Seat Systems for Maximum Driving Comfort
Pneumatic Seat Systems with many added functions are especially comfortable and offer clear technical advantages. The multi-contour seat function allows vehicle occupants to adapt the contour of the seat to their individual requirements. Via air cells integrated into the backrest and seat cushion the seat adjusts to fit the body. The optional massage function further enhances comfort for vehicle occupants on long journeys by means of alternate inflation and deflation of the air cells. The drive dynamic function automatically adapts the side bolsters of the seat to the current driving situation, ensuring optimum stability for occupants at all times, even when cornering. The advantages of a comfort seat are thus combined with those of a sports car seat (Tsai, 1982).
2.4.7 Seat Foam
The angle of the seat surface is about 17° from the horizontal with an extra slightly softer area to resist forward slipping of the seat bones. The area behind the seat bones has been carefully designed to provide an upward force on the buttock behind the seat bones to provide extra pelvis support, i.e. to resist backward rolling of the pelvis. The example show in Figure 2.4.10.
Figure 2.4.10 Seat foam sectioned down the centre line
2.4.8 Arduino Gemma
The Arduino Gemma is a tiny wearable platform board with a lot of might in a 1″ diameter package and Powered by a Attiny85 and programmable with an Arduino IDE over USB and can be able to realize any wearables project. For the design a microcontroller board that was small enough to fit into any project, and low cost enough to use without hesitation and it has made by Adafruit based on the ATtiny85. It has 3 digital input/output pins (of which 2 can be used as PWM outputs and 1 as analogue input), an 8 MHz resonator, a micro USB connection, a JST connector for a 3.7V battery, and a reset button. The all component needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a battery to get started. The picture of Arduino is show in Figure 2.4.11 (Arduino, 2017).
Figure 2.4.11 Arduino Gemma
2.4.9 Ambient Temperature sensor
The ambient air temperature sensor is located behind the bumper or grill of many vehicles and monitors the air temperature outside of the vehicle. The ambient (ATC) or outside air temperature sensor is an (NTC) negative temperature coefficient sensor that informs the semiautomatic/automatic temperature control system of outside air temperature. The NTC sensor’s resistance decreases as the outside air temperature increases. The computer uses this input, along with other in-car temperature sensors to control temperature and blower speed. When there’s a problem with this sensor, performance will suffer and the compressor’s clutch may not engage.
Ambient air temperature sensor symptoms, like an inoperative clutch or input problems are diagnosed with a scan tool and a multi meter. Use a multi meter and verify manufacturer’s specifications, (~ 220-240 ohms at 70°-80° F), to test this sensor for proper resistance. So, the sensor when it reads 80°F (27°C) or higher, it will allow the operation of the ventilated seats during a remote start. When it reads 50°F (10°C) or lower, the system will allow operation of the heated seat during a remote start (Rosh 2013).
2.5 Type of car seat material
To fabricate a ventilated car seat Nylon Fabric, Faux Vinyl, PCV, Vinyl, Faux Leather, Suede and Brushed Nylon is the common material used. Each material is described briefly in section 2.5.1 to 2.5.7.
2.5.1 Nylon Fabric
Nylon is a durable, hard-wearing upholstery fabric which comes in many colours. There are plain and patterned designs and you can choose a type which best suits the interior of your vehicle. Because nylon is weaved, it is harder to tear than some fabrics. It is also very stain resistant, providing you can wash out any spills before the dry. It is also the most popular form of fabric found in most automobiles. It is available in many colours and is the least expensive form of trim for your vehicle (Willis, 2014).
2.5.2 Faux Vinyl
This is actually a vinyl which takes on the characteristics of leather or suede or other types of material. It is hard-wearing and can have the appearance and shine of soft leather or the dullness of fabric trim. Faux vinyl is a mock vinyl which emulates the real article at a fraction of the cost (Willis, 2014).
2.5.3 PCV Leather
Commonly known as soft plastic, this is a vinyl style-material that is pliable and easy to form. It stretches well and is used in lower-end models of cars and vans. It can be coloured or made in black and white, but it is notorious for being sticky to sit on during the summer. Heat has a tendency to make the upholstery sweat and the driver of the vehicle is best advised not to wear shorts in the summer if their vehicle is lined with PVC (Willis, 2014).
Easy to wipe clean, durable and hard wearing, vinyl is another coonly used material in the making of automobile upholstery. It has similar properties to PVC but vinyl can soft, hard, pliable or firm. You might be aware that old LP records were made from vinyl but, because it is used in a different capacity for upholstery, it can be as soft as velvet although it will still make the skin sweat during hot periods of weather (Willis, 2014).
2.5.5 Faux Leather
Faux leather is a very versatile material that can be made to appear like almost anything. People have covered their car seats in fake crocodile skin, fake snake’s skin and even dinosaur prints. It behaves like leather and is easy to wipe clean. Spillages can be quickly dealt with so faux leather doesn’t stain easily and is very durable (Willis, 2014).
Cloth-based suede fabrics are a nice choice for an automobile interior. Suede is soft to the touch and feels like brushed cotton. This automobile fabric is not used as often because it stains easily and it not as durable for many types of automobile use (Willis, 2014).
2.5.7 Brushed Nylon
Brushed nylon is soft and warm and ideal for an interior seat cover or door trim. It is a thick fabric that is usually just under a ¼ thick when used in vehicles. It seems well and is a firm, durable material which is quite hard to tear (Willis, 2014).
2.6 Type of material duct
Ducts are conduits or passages used in heating, ventilation, and air conditioning (HVAC) to deliver and remove air. The needed airflows include, for example, supply air, return air, and exhaust air. Ducts commonly also deliver ventilation air as part of the supply air. As such, air ducts are one method of ensuring acceptable indoor air quality as well as thermal comfort. Each material is show in section 2.51 to 2.5.4.we decided the flexible duct with aluminium is our material use to connect the airflow to the car seat.
2.6.1 Fabric Hose
This is actually an air distribution device and is not intended as a conduit for conditioned air. The term fabric duct is therefore somehow misleading; fabric air dispersion system would be the more definitive name. However, as it often replaces hard ductwork, it is easy to perceive it simply as a duct. Usually made of polyester material, fabric ducts can provide a more even distribution and blending of the conditioned air in a given space than a conventional duct system. They may also be manufactured with vents or orifices. Fabric duct offers also many benefits such as low cost, lightweight and easy installation, a uniform distribution of air, and a wide spectrum of available colours and sizes.
2.6.2 Metal ducts
Such ducts are made from sheet metal (galvanized or stainless steel, copper, aluminium), cut and shaped to the required geometry for the air distribution system. Since metal is a good thermal conductor, such ducts require thermal insulation, the commonest material for which is glass wool, usually in roll form (known as ‘wraps’ or ‘wrapped insulation’), wrapped around the outer duct wall. Wraps incorporate an aluminium foil facing that acts as a vapour barrier. Insulation can also be installed on the inner wall of the duct (‘duct liners’), as glass wool duct wraps or duct slabs faced with a glass matting or mesh providing acoustic insulation and strengthening the inner face of the duct.
2.6.3 Flexible duct
Flexible ducts these usually consist of two aluminium and polyester concentric tubes. A glass wool layer is inserted between the two tubes as thermal insulation. Their use is generally limited to short lengths, due to high pressure drop-off and the acoustic. The ducts can be deployed in hardly accessible places of the building and when it is difficult to plan how to connect boxes to the suspended ceiling. With 10-metre sections you can save time, as you do not have to work with short sections, and 120cm large cartons make their handling and storage quite easy. With its 25mm thick mineral wool insulation and a perforated tube inside, the duct also serves as a silencer.
2.6.4 Plastic ducts
This category includes ducts made from plastic or foam boards, shaped by cutting and folded to produce the required cross-sectional geometry. Boards are faced usually with an aluminium coating both internally and external. The main drawback of this type of ducting is their fire classification. Even if they comply with local standards, when exposed to fire they often exhibit poor performance in terms of the production of both smoke and flaming droplets.