Tcp Doc Vivec Rehman

8/7/2019 Tcp Doc Vivec Rehman

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Technically Complex Project

Low Power Air Cooling device for

middle class bedrooms

Vivec Rehman

PG Product Design 2009

National Institute of Design

Guide : Prof. Praveen Nahar


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Initial Design Brief

Energy reuse in domestic

environment

Tapping the mechanical energy from a fan/air

conditioner to power other appliances in order

to make more efficient use of

electricity


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Overview of Research

Initial market and internet research of air coolers, air

conditioners and ceiling fans.

Observation of usage pattern of the above products among

users. Questionnaire and interviews at middle class residential areas

covering most age groups.

Open discussions at households to understand how a family

or group of families perceives an air conditioner

Discussing Technological innovations and the basics of HVAC

with experts from the industry.


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User Feedback and Inferences An air conditioner is considered a luxury

in middle class homes.

People change their sleeping position in

summers so that the fan is above them

so they do not use an AC because fan is

in the middle of the room while bed is

in a corner.

When air conditioner blower is not

close to the bed, people set a very low

temperature which increases electricitybills drastically.

A window AC produces too much noise

so nowadays people use split ACs only.


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Users often set the temperature very

low for a few hours at night and then

increase it in order to save electricity

but it consumes more electricity.

Conscious consumers use the timer

mode and set a constant temperature

of around 24c.

A single air conditioner can increase

the bill by 1.5 to 2 times in summers.

Users also say that expensive 5 starrated ACs do not make a vey big

difference in the bill.

User Feedback and Inferences


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Users also keep the fan switched onalong with the AC because the ACblower does not provide very efficientair circulation.

Air conditioners are installed in

parents room small children sleepwith the parents in summers.

None of the users own an air cooler. Afew used to have an air cooler earlier.

There is a problem of dust

accumulation on fans. Has to becleaned very frequently in dustyplaces.



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Old people feel uncomfortable becauseof choppy effect of air from ceiling fans.

Ceiling fans are about 1.5 feet below theceiling.

Split ACs are 8ft above the floor on wallsadjacent to the bed.

Installation and maintenance has to bedone by professionals and is difficult inhigh rise buildings .

Window ACs block the entire windowand cannot provide efficient circulationbecause they are at a lower height thansplit ACs.



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People prefer split ACs over portable ACssince they do not occupy any floor spaceand look neat even though split ACshave longer installation procedure.

Most families have just a fan in thebeginning and later upgrade to an A/C.

Ceiling fans have 5000cfm airflow whileair conditioners have 4 cfm/sqft air flow.

A\Cs are used max. in summer(6-8 hrs

per day),5-6 hrs in monsoon and 0-2 hrsin winter.

In old houses wiring has to be changedwhen installing an A/C since it usuallyrequires high current



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General Layouts of bedrooms


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Pictures from Research


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Market Research

Air conditioners in the Indian Market areusually vapour compression type in split or

window configuration.

Thermoelectric air conditioners are used in

the telecom industry for localised cooling.

Cost is pretty low but increases if cooling isdesired for a larger area.

Portable ACs are now available but have

very low acceptibility.

Split ACs are gradually taking over the sales

charts because of low noise, betterlooks and efficient circulation.

People buy air coolers only in dry and hot

places like Madhya Pradesh and Rajasthan


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Cost of ceiling fans may vary from Rs. 1500to Rs 4000 or more.

Only a few high-end fans have remotecontrols.

Bladeless fans are fancy and are sold atvery high prices (Rs 12000 for table fan).

Solar powered air conditioning has beenintroduced in large installations.

Split ACs cost around Rs 25000 whilewindow ACs cost around Rs 18-22000.

ACs with 5 star rating cost almost Rs 8ooomore than normal ACs and recovery timefor extra cost is high.

Market Research


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The major companies making ACs are LG,Samsung, Onida, Hitachi, Daikin, Videocon,Haier, Voltas and Electrolux.

There are local and Chinese manufacturers

who sell ACs at a relatively low price butconsumers do not trust them because ofpoor service networks and marketing.

Cost and energy consumption are majorfactors guiding the choice of consumers.

Colours of most air conditioners are whitebecause walls are also white in colour.

Ceiling fans are either white or dark brownin colour.

Market Research


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OpportunityMapping

There is an opportunity to combine the ceiling

fan and air conditioner blower into one unit

which is ceiling mounted for better circulation

and increase the utility of the product.

Ceiling fans are not configurable so they cannot

cover the entire area of the bedroom.

There is no low power air conditioner available in

the market that provides localised cooling.

People have been making such coolers in foreign

countries at home to provide cool air in a

particular space of the room.


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Technology Used

The blower is based on the principle ofviscous shearing of air.

The air escape at high speed from a slitcauses air around it to be dragged with itcreating a low pressure area which draws inmore air thus creating a laminar flow of air.

Thermoelectric outdoor condenser unit isused to chill brine/refrigerant and send itthrough the heat exchanger built into the airhandling unit in the room.

A smaller capacity compressor(DanfossBD50) used in truck cabins could also beused in place of the thermoelectric unit.

Both thermoelectric and Danfosscondensers are used in trucks and caravans.


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Design Brief

Air ventilation and cooling device for middle classhouseholds (bedrooms)

A split system with condenser outside the house.

Will be able to replace a conventional ceiling fan .

Reconfigurable design so that the flow of air is

directly on the bed where 2 people are sleeping. Has a dust filter and ioniser to control dust and air

borne bacteria.

Installation easy with minimal changes to existing

connections and fixtures

Can be connected to an Air conditionercompressor(centralised cooling) as well as a

thermoelectric brine based cooling system(localised

cooling)


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Cost under Rs. 12000.

Adequate airflow for 120 sq.ft. room(size of

bedroom in middle class homes).

Efficient and flexible airflow distribution so that

a higher temperature setting can be used.

Adjustable speed and low power DC motor forimpeller.

Adjustable temperature(18-30c), blower

vent,speed and timer via remote control.

Easier to clean than a ceiling fan and replace

dust filter.

Glossy texture for a clean and dust free feel.

Dimensions : L 1800 X B 1500 X H 200(in mm)

Weight of air handling unit 6 kg (with heat

exchanger)

Design Brief


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Power consumption of air handling unit- 90 W Max Power consumption of condenser unit- 400W

Size of outdoor unit 320 X 180 X 250 (in mm)

Noise not more than 40dB

Split unit when used as an A/C for better sound insulation

Weight 7 kg max of outdoor unit

No heavy ducting required as in case of portable air

conditioners.

Could be operated directly using solar energy since it uses

a DC motor and thermoelectric unit.

Condenser unit is easy to mount and remove formaintenance.

Design Brief


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MoodBoard


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Product Placement

The product shall be an air conditioner for localised cooling i.e. for the

area where people are sleeping.

It will be positioned between an air cooler and a high end air conditioner.

It shall circulate cold air in that particular area and not in the entire room.

The blower unit can be used as a ceiling fan and can be configured

according to the occupants of the room and season in order to provide

airflow in the area where people are sleeping.

Ambient temperature of the room will eventually drop but the rate will

not be as fast as a 1 ton AC.

It will have power saving functions like timer.

It will also have dust filter and ioniser in the central blower to clean air in

the room.


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Technical Details

6 Thermoelectric modules 40 X 40X 6 (in mm)

6 X 50 = 300 W

Heat sink aluminum 250 X 200 X 120 (in mm)

2 Fans 120 X 120 X 20 (in mm)

2 X 20 = 40W Pump 80 X 50 X 50 (in mm) 30 W

Size of 2 copper reservoirs 250 X 120 X 40

volume of brine stored 2 X 1.2 = 2.4 litres

4 pass heat exchanger on both reservoirs

1100 -1500 W cooling capacity

Condenser unit


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3 high speed blower motors (100000rpm)

100 length X 80 dia.(in mm) 3 X 35W = 105 W

1 high torque motor to change position (300rpm)

80 length X 60 dia (in mm) 20W Heat exchangers on both sides 400 X 100 X 40 (in mm)

Airflow of individual blower 1500 cfm

Technical Details

Air handling unit


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Configuration of outdoor unit

Circulation pump

2 brine solution cases

Exhaust fans

Heat sink

6Thermoelectriccouples


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Configuration of Air handling unit

Dust filter

Position control

motor

Blower motor

Heat exchanger


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Concept Explorations


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Digital renders of concepts


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Mock-ups w.r.t bedroom


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Outdoor unit CAD model


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Exploded view


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Blower unit CAD model


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Exploded view


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Display on Blowers

Each blower will have a separate display.

Display will show speed of the blower in the form of a bar graph

and a red/green light to show on/off.

Speed of each blower can be set individually.

Graph for speed will have 5 bars. Speed will be represented with

blue light while other bars will be white in colour.

When speed is being changed for a blower, the light will flicker to

notify which blower is being controlled.

Both blowers can only be moved together. Lights shall be covered by a frosted screen so that it is not too

bright for people who are sleeping.


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Remote Control Buttons A/C on, mode,Up/down keys, blower selector, blower on/off,

position change. There is a display for the temperature status of individual blowers and the

mode.

Mode has functions like Jet cool and timer.

When the unit is switched on using the on/off button at the top, it enters thefan mode.

To switch on the air conditioner mode, the user has to press the a/c buttonwhich will be backlit when a/c is switched on.

To change speed of individual blowers, the particular blower button is pressedfollowed by up/down key to change speed

Pressing the up/down button without selecting a blower would changetemperature.

To change position, press the POS. button along with up/down key to move

blowers forward and backward. To go to Jetcool mode press mode once and then POS. to start jet cool for 15

minutes

To set timer, press Mode twice and set time using Up/Down key and selectusing Pos.

Size 100 X 80 X 10 (in mm). Button size not less than 1 cm each.


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Remote Control CAD model


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Exploded view


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Orthographic DrawingsBlower unit


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Orthographic DrawingsOutdoor unit


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Orthographic DrawingsRemote Control


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Outdoor unit render


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Outdoor unit render


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Blower unit render


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Blower unit render


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Blower unit render


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Remote control render


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Colour and texture

White colour has been chosen as the basic colour of all three parts

to give a clean feeling and to make it less conspicuous when fixed

on a white ceiling.

Rubber parts are made like pipes and suction cups, buttons for

remote control are made in a very light blue colour.

A few plastic inserts are made light green in colour. All parts except the rubber parts have a medium gloss texture for a

clean and high tech feel.


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Materials and Manufacturing

Each blower is split into 2 parts horizontally that are injection

moulded in ABS with stainless steel inserts to provide structural

rigidity and strength.

These parts are then screwed together for assembly.

The removable heat exchanger and dust filter parts are made in PP.

Slot for the movable blowers is made of nylon for friction

resistance.

Rubber parts are moulded in nitrile rubber.

Frame is fabricated from Mild steel and powder coated in a dull

silver colour.

Blower unit


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Front and rear sections are formed in sheet metal and the mid

section is cut and welded to the rear part

The heat sink and other parts are mounted on the rear part.

The injection moulded HDPE hand grips are then stuck to this part

using industrial glue and then the front cover is screwed on.

Pipes for heat exchangers are taken out from the rear.

Materials and Manufacturing

Outdoor unit

Remote control

The remote control is split along horizontal axis into two injectionmoulded LDPE parts and the battery cover is also injection

moulded LDPE.

The screen is polycarbonate and buttons are neoprene rubber.


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Unique Features A Hybrid between an air conditioner, air cooler and ceiling fan.

Can direct its airflow usefully to provide comfort to occupants of the roomso the cooling is a combination of sensitive cooling of the AC andevaporative cooling due to moisture on the skin.

Can provide sensitively cooled air to the place where people are sleepingrather than circulating it throughout the room so less power is required.

Since air is first cleaned and then passed through the fan, it does not

require cleaning of accumulated dust like traditional ceiling fans. It uses the mounting hook of the traditional ceiling fan so no extra fitting

are required.

Remote control is provided with timer and jet cool option.

Temperature up to 18c can be set.

Less than 50% power consumption compared to a 1 ton AC.

Airflow is laminar unlike the turbulent flow of ceiling fans so people do notfeel uncomfortable when sleeping under it.

May also be operated directly on solar power since all the components areDC .

Low noise compared to a ceiling fan since motors are brushless DC type.


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Prototype


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Prototype


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Prototype


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Costing

Motors 3 X Rs 800 = Rs 2400 Heat Exchangers 2 X Rs 1000 = Rs 2000

Slider motor Rs 300

Metal parts Rs 1000

TECs 6 X Rs 800 = Rs 4800

Heat sink Rs 1000

Indoor panels Rs 2000

Outdoor panels Rs 1000

Total Rs 14500


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Feedback

U

sers were amazed to see a fresh new concept for the run of the mill airconditioner. They also liked appreciated the fact that it could replace a fan

too. They were also impressed about the slimness of the device and its

claimed airflow pattern generated by its form. The low power

consumption and strategy of cooling the area above the bed was also

appreciated. The futuristic form of the sliding blowers was also quite

intriguing for them. The compactness of the outdoor unit also drewconsiderable attention.

However, a few users expressed concern about the mechanism of sliding

the blowers and suggested it should be more sturdy. They also suggested

that I should conceal the pipes inside the metal tubes holding the entire

unit on the ceiling. They also said they would rather prefer something thatis more firmly fixed to the ceiling even if a few hole have to be drilled for

screws.

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