From UBC Wiki


Project: Energy Recovery Dryer

Welcome to team 2. We are 12 first year students from UBC's Vantage Applied Sciences determined to design an innovative and efficient dryer capable of energy recovery.

Project Overview

The project consists in designing a scaled-down prototype of an Energy Recovery Clothes Dryer (EneRec dryer). Unlike conventional clothes dryer, in which the hot air that has been blown over the clothes is vented out, the EneRec dryer’s objective is to recover some of the heat generated and cycling it back into the system, eliminating the waste. This saves energy and contributes to sustainability.

Problem Statement

The guiding statement indicating the issue this design aims to address:

One issue with standard dryers that are on the market today is that they consume and waste a lot of energy by constantly heating fresh air and venting it out after a single use.


General Goals to fulfill as fully as possible:

- Efficient energy recovery

- Fast clothes drying

- Intuitive User Interface


General Functions the EneRec Dryer is capable of performing:

- Buttons and LCD display to communicate drying time, temperature, and dryness with the user.

- Can detect temperature and humidity and stop automatically in automatic mode.

- Time alerts to inform on the cycle status.

- Condensed water collection.

- Can be hung from a wall

- Lint filtering


Qualities that the EneRec Dryer must comply with:

- Drying a cotton 15 x 15 cm handkerchief in less than an hour.

- Size limitations of 250 x 220 x 300mm and a 0.5 L capacity in the drum.

- Electrical power consumption of 12 V AC and 12 VA.

- 8 weeks time to develop the design.

About Us

There are 12 members in this team, which are divided into 5 subteams. In the following, it is explained what each subteam is in charge of working.

Documentation: Report, Poster, and PowerPoint.

User-Interface: Programming Operation, Electrical Connection.

Mechanical: Drum Drive, 3D designing, CAD File, and Heat Exchanger Design.

Electrical: Electrical Structure, Heater, and Programming.

Structural: Structure Design and Anime & UI CAD.

Gantt Chart

Table 1 below shows the schedule of all the subteams' tasks and their beginning and ending dates.

Table 1. Gantt Chart for Team 2

User-interface Design


The user-interface subteam is required to work on the operation of the program, user-interface program, LCD connections, and Buttons connections.

The operation of the program includes sequence of starting, stopping, etc.

The user interface program is required to read the buttons and displaying the LCD.


The objective of the user interface sub-team focuses on anticipating what users might need to do and ensuring that the interface has elements that are easy to access, understand, and use to facilitate those actions: In short, to provide a user-friendly environment. These elements include starting the dryer, selecting menu options of their own choice, to stopping the dryer. This will be done by using 3 buttons. The additional features given to make the dryer more user-friendly are: alerting the user by using electrical components like LED and buzzer and displaying “time remaining” so that the user knows how long it will take to dry his clothes.


The User Interface sub-team circuit aims to function in way that gives the desired output by constantly monitoring the inputs. This includes a working LCD, registering button inputs, proper display of messages in LCD as per the user’s convenience.

Photo of working LCD


The constraints for the UI circuits includes -

  • using delay functions to register small press or long press to the button as a single input at a time.
  • displaying long messages from right to left across the LCD is also one of the constraints to the circuit.
  • Auto (just press a start button),
  • use default settings for time in automatic mode
  • temperature and target humidity settings
  • In manual setting, the time can't be above 60 mins
  • In manual settings, the temperature and humidity sensor options are given High, Low and Mild values as per the per-set variables

Design Description


1. Buttons

For button design, we have choose the following layout-

Circuit for Button design
Button arrangement
Button design

This design has three buttons as its input. These three buttons help the user to navigate through the menu options provided in the LCD efficiently. Moreover, these buttons are used to navigate up/left and down/right at a time. Furthermore, there is one button in the centre which plays the role of confirmation/ “Ok” button.

This design was chosen for this project as-

1) It consists of less wires. Thus, the system has less surface area which helps in quick maintenance.

2) The design is easy to access across breadboard as it has three buttons and the wires are less crowded at the negative terminal.

3) Three buttons provide convenience to the users than five buttons.

4) These three buttons can be used for multi-tasking. (eg button can instruct to go left or up at a time)

5) The contents of this design can be kept organised.

2. Main Menu Page

The following design for main menu was chosen -

Menu page

The menu page provides three options to the user to select from. The options are:

1) Automatic

2) Manual

3) Less dry

1) Automatic

If the user wants to put the drying process in automatic then the software determines the pre-set values of the different variables (time, temperature and level of humidity) according to the sensors inside the drum drive. In addition, the software decides these values on the basis of the optimum temperature, optimum time for dry and optimum level of humidity. These values are determined by the software

2) Manual

In this process, the user decides the value for time, temperature and level of humidity. In order to select this option, the software provides a sub-menu options to the user for selecting the values for the different variables.

Sub-menu options for manual settings

In this sub-menu option, time, temperature and humidity has to be selected manually in order for the dryer to run. Over here, the user can use the arrow pivot to navigate through the options given. If the "Ok" button is pressed, then a new page is opened for the respective sub option.

Time setting

In this example, "Ok" button was pressed when the arrow pivot was at time. Therefore, a new page for time opens. In this, the user can increase the time by 5 mins up by pressing the "UP" button or decrease the time by 5 mins by pressing the "DOWN" button. Once done selecting the variable, the user can press the "OK" button to go back to the sub-menu option page.

For temperature and humidity, the following images provide the description of the sub-menu. In addition, same procedures as time settings is followed. However, several acronyms signify L - Low, M - Mild and H - High. The same meaning of acronyms is also provided to the user through warning messages at the beginning. In order to see the whole procedure, please visit the step by step procedure video below.

Temperature setting
Humidity setting

The respective setting is saved and when the user holds OK and Left/Right Button for 2 seconds, the process of drying starts.

3) Less dry

In this mode, the software determines the values for time, temperature and humidity level on its own. These values are decided on the basis of less temperature, less time and more humidity level.


1.1 Flowchart
1.2 Flowchart

The program of Team 2 is available here - Sandbox:Team 2 EneRec codeS

Additional features

Components involved Purpose Objective
LED and Buzzer Alert the user when the drying process has completed. The buzzer makes a sound and LED flashes repeatedly
LCD To provide a user friendly environment Show animations when the device starts and in between the menu options
Switch detector To alert the user when the door is opened To check the state of the switch repeatedly while the drying process is in continuation
Humidity/temperature Sensor To check the level of dryness and temperature To check the level of humidity and temperature repeatedly in order to prevent the damage on fabrics


There are few things which can be improved. For example, we can use long press on OK button to select the manual settings. Moreover, we can also use a bigger LCD display to showcase animations. We can also add more functions to the EneRec Dryer. For example, function that decides time, temperature and humidity on the basis of fabric inside.

Mechanical Design


The mechanical sub-team is expected to generate, evaluate, sketch and model designs for the mechanical components of the Dryer Machine, following specific constraints and guidelines.

The group is responsible for working on a drum drive, some 3D printing components, a sensor mount, an anime and computer-aided designs for electrical parts, a heat exchanger and a lint filter.


  • Design an energy recovery clothes dryer that functionally dries clothes without any hindrances.
  • Design all the internal mechanical components for this dryer, being careful to make sure that they fit accordingly.
  • Choose the best position to fixate the mechanical components inside the dryer, taking into account the function that it has and how effective a position might be for that.
  • Maximize the effectiveness and minimize the possibility of eventual problems and material loss.
  • Draw Computer-Aided Designs (CADs) of various electrical components.


a. Drum: the rotational device in which clothes are put and dried.

b.  Drum drive: a mechanism to rotate the drum using motor.

c.  Motor support: a 3D printed material that holds the motor in place.

d.  Heat exchanger: system used to transfer heat between two or more fluids.

e. Lint filter: a design used to contain lint and prevent it from getting to the copper pipes.


Minimum capacity of 0.5 L (capable of drying a 15x15cm cotton handkerchief within an hour).

  • Components must fit in the dimensions of 250x220x300 mm.
  • Motor should be supported by motor support.
  • Sensor mount must be compatible with sensor designs.

Drum Drive Mechanism Design Alternatives

The main components of a dryer's drum mechanism are the drum itself and an electric motor. The electric motor is used to rotate the mechanism of the drum, and the drum is used for the storage of the clothes that need to be dried. With this concept in mind, different ideas for this mechanism have been drafted.  

Figures 1, 2, and 3 show the different ideas for the mechanism of the Energy Recovery clothes dryer, and Figure 4 shows the draft of the heat flow in the heat exchanger.

Figure 1
Figure 2
Figure 3
Figure 4


Idea Advantages Disadvantages
  • High efficiency
  • Easy rotation (idler pulley)
  • The belt might tear appart (higher tension)
  • The idler pulley might wear over time
  • High efficiency
  • The belt might still tear appart
  • Might be harder to rotate the drum (no idler pulley)
  • More durable (gears are less likely to break)
  • Slow rotation of the drum (worm gears)
  • High energy loss
  • More durable (gears are less likely to break)
  • Good efficiency
  • Still some energy loss

As can be seen, Figures 1 and 2 follow a pulley and belt mechanism, whereas the ideas presented in Figure 3 follow a gear mechanism. In Figure 3, there are two different gear mechanisms for the drum drive. One idea uses the worm gear, whereas the other uses a spur gear. For both concepts, the drum is designed to easily rotate when there is a transmitted movement from the electric motor through the worm or spur gear. The advantage of this idea is that the mechanism will likely be more durable than that of the belt and pulley, and the disadvantage is the high energy and heat loss due to the use of these gears.

On the other hand, Figures 1 and 2 show different features for the belt and pulley mechanism. In Figure 1, the idea adds an additional component compared to Figure 2, which is the idler pulley. The advantage of this pulley is that it increases the belt's tension with the drum, which makes the drum drive mechanism run smoothly. However, the belt might also break due to this tension, which would decrease the mechanism's durability.

Therefore, after a careful evaluation, the idea that was used for the drum drive was the one depicted in Figure 1.

Basic Features


  1. Drum Drive Components
  2. Temperature and Humidity Sensor Mount
  3. Lint Filter
  4. Heat Exchanger
  5. CAD Models of EE designs
  6. 3D Printing Parts
  7. Animation

1. Drum Drive Components

Figure 5.1: Motor Suport

The chosen drive mechanism consists of a belt and pulley system, demonstrated in Figure 1. This pulley system is connected to the drive motor and the belt is wound over the drum through the idler pulley. The motor was placed with a distance from the drum in order to reduce the vibrations of the dryer, thus, avoiding noises, increasing its lifetime, and causing less wear and tear to the belt. The addition of the idler pulley to this system also increases the tension in the belt, making it easier to rotate the drum.

Motor and Motor Support

The motor support is an essential component that holds the motor in place. It was made by screwing a 3D printed parallelepiped to the motor by using its specific holes for this function. Additionally, an L-clamp was attached to this support in order to fixate the entire component to the dryer's wall. This design aims to save material and cut costs, as it does not take an entire extra column to fix the motor.

Idler Pulleys
Figure 5.2: Idler Pulley

The idler pulley is meant to increase the tension in the belt and enhance the performance of its rotations. It was fixated and screwed to the ground by using a semi-oval clamp. However, the mounting still provides the idler pulley with the possibility of moving along the axis that is parallel to the drum's rotation. Although this component is part of the basic elements required for the project, an extra feature has been attached to it: a spring. Instead of fully fixing the idler pulley to the ground, this specific design thus focuses on making it move along one axis. The spring is, then, attached to it and allows it to adjust its position as the belt either expands or contracts due to the heat. This prevents the belt from tearing apart.

Figure 5.3: Dryer's Drum

The drum comprises the temperature and humidity sensor and the lint filter. It also has three baffles to increase the air circulation.

2. Temperature and Humidity Sensor Mount

Figure 6.1: Sensor[1]
Figure 6.2: Sensor Mount - Back and Front View without the Drum

For precautionary measures, the sensor was placed inside of the drum, close to the copper tubes. This was done because the humidity sensor had to be inside of the drum to get accurate measurements. Therefore, the back of the drum is the most convenient place to put the sensor and sensor mount. Once the sensor is attached to its "mounting box" - which is already a part of the back of the drum - it gets connected to the wires that will be going to the electrical boards through a square hole comprised by this box. Look at the Fig. 6.2 for your reference. This works efficiently to detect the maximum temperature and humidity.

3. Lint Filter

Figure 7: Lint Filter - Before and After Resizing

A lint filter is used for preventing the lint that enters the copper pipes used in the design. This is used as a great feature to make sure the dryer runs smoothly and that there is no blockage or air in these tubes. The pictures "Lint Filter (isometric view)" and "Lint Filter (back view)" show the lint filter used for the Energy Recovery Dryer. As can be seen, it is designed in such a way where it can contain lint and be connected to the copper pipes. It has two mesh plates. The outer mesh plate is used for the entry of lint and air, and the secondary mesh plate is only used for the entry and exit of air.

In addition, the lint filter was redesigned to meet the specific constraints of the CAD model and to fit the thickness of the baffles of the drum - Figure 7.

4. Heat Exchanger

Figure 8: Heat Exchanger

A heat exchanger is a system used to exchange heat between two (or more) fluids. The heat exchanger in our dryer works upon the cocurrent flow.

5. CAD Models of EE designs

Figure 9.1: Breadboard[2] with Support
Figure 9.2: Breadboard[2] Mounted
Figure 10.1: Arduino[3]
Figure 10.2: Arduino[3] Board Mounted

The computer-aided designs necessary for the electrical/electronic sub team comprise a temperature and humidity sensor[1], an Arduino board[3] and a breadboard[2]. Once these models were downloaded from the website, they had to be mounted to the actual dryer CAD. As mentioned, the sensor temperature was fixed to the back of the dryer, and as the Arduino board already contains screw holes, the only extra support necessary was for the breadboard. Thus, a 3D printing based component was designed - with a "grids format" in order to save material. The Arduino was, then, attached to the back of the dryer and the breadboard, screwed to the ground.

6. 3D Printing Parts

As mentioned before, there are only two 3D printing parts for this mechanical project: the support for the motor and the one for the breadboard. Both of them can be seen in green in the Fig. 5.1 and 9.1.

7. Animation

The animation of the drum rotating can be found in the last video of the "Virtual and Actual Prototype Demo" session of this page.

[1] Refer to this external link to download the entire SolidWorks CAD model of our team's EneRec Dryer, including the mechanical sub-team's features.

Electrical Design

Overview of the electrical sub-team

The electronic and electrical sub-team (EE team) is responsible for all electronic circuits, including but not limited to motors, fans, heaters, power sources, and sensors. It also manages to program the automatic and manual modes of the EneRec system. The connection can be seen in Figure 1.

Figure 1. The connection of all components.

Main Component Lists

Table 1. List of the key electrical components.

Component Specification
Motor Hobby Gearmotor, Yellow 200 RPM, 3-6VDC
Fan 12 VDC motor
Heater 33 Ohms 7W resistor  
Temperature and Humidity Sensor DHT11, 5V
Microcontroller Arduino Uno R3 ATMEGA328

Table 1 lists the major components and specifications of the EneRec Dryer. All of the used components were chosen based on what was provided by the course instructor.



The functions of the electrical/electronic sub-system are:

  • Tracking the temperature and humidity in the clothes dryer by a DHT11 sensor
  • Using the motor to rotate the drum continuously in a different direction
  • Using heater to dry the clothes in the drum
  • Circulating the air inside the drum by a fan
  • Changing temperature in the drum based on the user settings
  • Containing automatic mode to dry the clothes
  • Setting manual mode based on dry time, temperature, and dryness


The design objectives of the electrical and electronic sub-systems are:

  • To make the clothes dryer work more efficient
  • To make the drying time shorter
  • Ensure all the clothes are dry fully in a certain time
  • Ensure clothes are not overheated and avoid clothes damage
  • Ensure cost-effective design


The EneRec Dryer must meet the following constraints:

  • The maximum power voltage is 12 AC and 12 VA
  • All the components need to place inside the clothes dryer
  • The voltage outside of the dryer must be safe for the people who use it
  • The motor, heater, and fan should be able to work at the same time

Design Components

Power Source

The constrain of this project is to use a maximum voltage of 12VAC. Because the majority of the components utilize DC, the EE team uses a bridge rectifier circuit to complete the conversion. With diodes and capacitors, the voltage leaving the rectifier is 12VDC. To power the Arduino Uno, it requires a ~9VDC. Therefore, a voltage regulator and capacitors were used to drop the voltage from 12V to 9V, as can be seen in Figure 2.

Figure 2. An AC to DC circuit.
Table 2. A weighted comparison chart of a 12VAC source and 12VDC source.
Objectives Weight 12 VAC (%) 12 VDC (%)
Safety 0.45 50 50
Cost effective 0.45 50 50
Easy to implement 0.10 60 40
Total 1 51 49

With the given constrain, the EE team compares the AC and DC voltage sources to determine which one is better. Table 2 shows the evaluation of the 12 VAC and 12VDC sources using a weight comparison analysis. For safety, both options could damage other electrical components if not connect properly but is safe for the EE team to use. In terms of cost-effectiveness, the 12 VAC source is a bit expensive, but it is neglectable. Alternatively, the 12 VAC is faster to implement than the 12 VDC because there was a lecture explains the working principle of an AC voltage. From the given comparison, the 12 VAC sources win 12 VDC sources by 2 percent. This indicates that 12VAC is better in terms of the requirements listed on the right.

Fan Circuit

The power of the fan circuit is a 9VDC which comes from the power circuit. The components of this circuit include fan, resistor (R2, 10k), capacitor (C5, 0.1 u, > 50V), MOSFET (Q1), and diode (D1, 1A, 50ns). The purpose of using MOSFET is to control the fan speed through Arduino. The circuit schematic of the fan can be found in Figure 3.

Table 3. A weighted comparison chart of a commercial fan and a Do It Yourself fan (DIY fan).
Objectives Weight Commercial Fan DIY Fan
Time Consumption 0.5 90 10
Cost 0.5 60 40
Total 1 75 25

Table 3 shows the comparison of the commercial fan and DIY fan in terms of time to build and cost. The commercial fan takes less time to buy and transport from the shop because it only requires transporting at once. The DIY fan requires the EE team to communicate to the mechanical team, design the fan, 3D print it, and transport it to EE team members. In terms of cost, the commercial fan cost cheaper than the DIY fan. This is because commercial fan cost includes a fan and a motor, whereas the DIY fan includes a separate cost of a motor and the 3D print. Therefore, the EE team choose the commercial fan.

Drum Motor Circuit

The drum motor is connected to the PWM output digital 10 pin on Arduino, and the schematic for controlling the motor is by using +5VDC. In this circuit, it contains a motor, resistor (R3), capacitor (C6, C10), MOSFET (Q1), and diode (D1). The polarity (+/-) of the motor does not matter since the motor can turn in an opposite direction. The circuit schematic of the drum motor can be seen in figure 4.

Figure 4. The ciruit schematic of a single directional drum motor
Table 4. A weighted comparison chart of a commercial fan and a Do It Yourself fan (DIY fan).
Objectives Weight Commercial Motor DIY motor
Ease of use 0.5 70 30
Cost 0.5 65 35
Total 1 67.5 32.5

Table 4 shows the difference between the commercial motor and the DIY motor by looking at ease of use and cost. Like the fan, the commercial motor consists of a build-in gear system which easier to use and more reliable than the DIY motor. For the cost, commercial motor cost includes both the motor and build-in gear, while the DIY includes different prices of motor and 3D print gears. From these differences, the EE team decided to use the commercial motor.

Heater Circuit

The heater uses 12VAC as a power source. The power source is different from the motor and fan since the power of the heater does not come from Arduino – it comes from the breadboard. The way we control the heater is going to though digital output PMW 8 of Arduino. The components of this circuit are the heater, resistor (R1:10k, R6: 39, R7: 270, R8:150), capacitor (C7:10n), Opto Triac, LED2, and Triac (T1: 4A, 600V). The purpose of using Triac is to control loads in AC circuits and to control the heater using Arduino. The circuit schematic of the heater can be seen in figure 5.

Figure 5. The circuit schematic of a heater.

Temperature and Humidity Sensor

The temperature and humidity data are collected via the DHT11 sensor. Another model of this sensor is the DHT12 that provides higher accuracy, but higher cost[4]. The accuracy of the DHT11 could provide enough information about the environment inside the drum and also cheaper.

Figure 6. The schematic of the DHT11 circuit [4].

Arduino programing

Figure 7. A general flow chart of the programming.

Figure 7 shows an overview of the programming aspect. The flow chart can be read from right to left. On the rightmost column, four main components can be controlled by a microcontroller. Then each of those components will be controlled by four primary functions, the middle column. The primary functions will then be used by secondary functions, on the left-most column, which are the modes of the dryer. Finally, the secondary functions can be then used by the user interface subteam to run the input from the user.

Link to the code:

Extra Features

Reverse Directional Drum

Table 5. A pairwise comparison chart of a single directional drum and double directional drum.
Objectives Weight One Directional Drum (%) Double Directional Drum (%)
Efficiency 0.10 40 60
Drying Time 0.10 40 60
Fully dry 0.35 40 60
Cloth Damage 0.35 55 45
Cost effective 0.10 55 45
Total 1 46.75 53.25
TinkerCad circuit of reverse motor circuit.

The reverse directional drum refers to a circuit connection that allow the drum motor to spin forward and backward. Table 5 shows the pairwise comparison of a drum spinning one direction and the drum with reverse direction. As can be seen, the double directional drum receives higher score which indicates a better design. This feature is better than a single directional drum because it allows the clothes to not stick to each other which open more space for hot air to flow through. This makes the clothes dry faster in all edges. The double directional drum was created by a DPDT relays that makes the current flow in reverse direction.

Video of the revser motor:

TinkerCad Circuit:

Personify Dryer

This feature will be using every time the dryer completes drying clothes. Once the process arrives at that stage, the dryer will display jokes to the LCD and make the user laugh. This feature could encourage the user to use the dryer more often. This because every time the dryer completed its task it will always show new jokes. Those jokes are chosen from different databases like a website called[1]. An example of a joke could be, “A comedian will never be able to tell a dirty laundry joke. They will just come out clean”[1].


There are many improvements that the EneRec dryer to perform better. For instance, the heater circuit can be more simplified to use fewer components. It will be great if the breadboard is longer so that the whole circuit is not too compact. In addition, it is better to plan a schedule to leave no major tasks behind like the programming behind since it is one of the most important and challenging tasks.

Structural Design


The structural team is required to work on the enclosure, opening/holes, door & latch, animation of the door, CAD files of UI parts.

The enclosure consists of all parts and elements to contain and attach all parts of the dryer into one cohesive unit. This includes openings and their doors and latches and the placement for buttons and interfaces. An animation for the door movements is also included in the requirements as to demonstrate the functionality of the enclosure. All of these are presented through CAD design.

Enclosure with openings, holes, door and latch


The objective of our design is to make an enclosure of clothes dryer (include door opening, water collection tray, LCD, and buttons) with safety and ergonomically convenient.  

1. The clothes dryer is highly ergonomical and saves room space.

2. The opening door and structure of enclosure is designed to provide maximum safety.

3. The function of the LCD and buttons are easy to use and practicable.

4. The water collection tray is designed to provide large space.

5. The dryer is mounted to the wall hence its usage is convenient for all age groups.


The functions of the structural sub-system are designing the overall framework for the clothes dryer which includes:

1.The door to ensure the clothes do not fall out.

2. LCD and buttons for user operations.

3. Water collection tray to collect the water from the dryer when it is working.

4. Extra hanger at the back to mount it on the wall.  


The enclosure designs are all constrained by size and the components they must contain. Because the enclosure is a shell for all other elements, this is logically constrained by the dimensions and requirements of all components like motor, drum, and heater. This design is also constrained by the maximum size for the whole dryer because the enclosure is the outermost part.

1. The size of the EneRec Dryer cannot not exceed 250 x 220 x 300 mm.

2. The dryer can be made portable but removing it from the hanger can cause slight inconvenience.

3. The Dryer should contain an LCD display and some navigation buttons for the user interface.

4. The temperature must be maintained and below the maximum heat resistance of the material.

5. The Dryer should not be too expensive.


Generating alternative sketches

The subteam has drawn 4 design alternatives for the door and enclosure, which can be observed on the following pictures:

3 sketches


There are the three views of our design: a to view, front view, and the right view.

The front view
The side view
The back view

The front view of the enclosure contain a dome shaped door and LCD panel with three buttons. The position of the display screen is above the controlling buttons because it can be convenient for the user to see the information for the dryer while making controls. LCD is used to present information about the time and temperature .The door is also designed in a way to make it easier for the user to remove or put the clothes in. In the right view of the design, there is a hole in the lower right corner. This hole is designed for the water collection tray, and the length and width of the hole are X mm and Y mm, respectively.

Door & latch


Several sketches were conducted for the shape and location of the door. While different types of doors such as Irish, side swing, and sliding are popular among users, the focus of all the designs was on side swing doors. Since the main customers of this dryer are college students, one of the factors considered along the safety and convenience is affordability. Implementing the side swing door costs considerably less than the other available options on the market. Also, since the dryer is mounted to the wall, opening the side swing door could be difficult, and inside the drum could not be visible.

While both doors, options 2 and 3, open from the same side of the dryer (front), opening the square shape door could be easier since its area is wider.

The dimension of the door is 180 x 180 mm. This door is attached to the right side of the dryer by two hinges.  

Door Design Evaluation
Square Circle   Top View Opening Weight
Safety 45% 35% 20% 40%
Convenience   47% 44% 9% 25%
Affordability   30% 60% 10% 25%
Space/Dimension 70% 20% 10% 10%
Total 44.25% 42% 15.25% 100%

Based on the 4 categories in the WDM chart, the square design was chosen as our door design in this project. The table shows that safety is the most important consideration, followed by convenience and aesthetics, and space/dimension ranks last.


The latches are designed with the purpose of locking the door while the dryer is operating and preventing any leakage.

WhatsApp Image 2021-06-29 at 23.28.16.jpg
WhatsApp Image 2021-06-29 at 23.29.49.jpg

User Interface CAD

We have come up with two designs for the control panel. The CAD models of two LCD panels were designed and evaluated, and the second option was chosen. For this evaluation, parameters such as safety, durability, and aesthetics were considered. The following chart was used to evaluate the LCD panels.

Two designs of the control panel
Weight (%) Control 1 (%) Control 2 (%)
Safety 50% 20% 80%
Functionality 25% 40% 60%
Durability 25% 30% 70%
Sum 100% 27.5 72.5
Location of the control Panel

For this wall-mounted dryer, the location of the LCD panel is chosen considering the user's convenience. In this case, the LCD panel is located on the front view, which is more accessible and visible to the user.

control panel position

Water tray standard design

Two trays were designed for this dryer which both have the same dimensions as follows: 84.5 x 40 x 25 mm. The dimension of the tray is chosen based on the limit for the weight of the dryer. Both designs also occupy a considerable small space. In design one, the water tray is fixed. However, the second design allows the user to empty the water tray using the designed handle. This extra feature makes the second design more suitable for the wall-mounted dryer as it can be empty by the user and keep the weight of the dryer lighter.

There are two standards for choosing the best design for the water collection tray, which are convenience and stability. Convenience refers to how ergonomical and convenient to reach the control panel. The feature for stability refers to the degree of stability that it is drawn from the dryer. After comparison, the Water Tray Collection 2 was chosen. Table below presents the alternative design for the water collection tray.

Weight (%) Water Collection Tray 1 (%) Water Collection Tray 2 (%)
Convenience 40% 45% 55%
Stability 60% 35% 65%
Sum 100% 39% 61%


Looking into the ergonomics for the design, we came up with an idea of a wall-mounted design, meaning that the dryer will be hung on the wall for better convenience. Since the dryer is heavy in real life, we also looked into the weight that the wall would have to carry. First, we was thinking about how to create a big attachment pad and screw the pad at the back of the machine to help the wall spread out the weight. However, in the end, we changed the idea into screwing more holes at the back of the dryer. By this way, the weight will be carried and spread out on the holes. To solve the problem of cool air coming out from the back, we would also need a hose to connect with the air hole.


Conclusion- End Product

The designed product is a compact dryer that recycles heat and dries clothes with less energy consumption, perfect for a single user household with small dryer needs. The 6 copper tube heat exchanger condenses water and moves heat back into the systems rather than venting it out, wasting less energy in heating fresh air. In the smart "automatic mode", humidity and heat sensors inform the system and avoid energy waste and running after the clothes are already dry. The compact design is ideal for users with small load sizes looking to not waste a whole traditional load's worth of energy for a single shirt. Together with the heat-exchange design and automatic mode options, this dryer is a great option for environmentally conscious users avoiding energy waste while drying clothes.


Assembly Drawing

The following files belows shows the exploded views for the assembly and connections between components for the Heat System, Drum Drive, and Enclosure with relevant dimensions.




Renderings and photo view 360

The following pictures shows the final result with renderings:


  1. 1.0 1.1 1.2 1.3 A. Kamarauskas, "Free CAD Designs, Files & 3D Models | The GrabCAD Community Library",, 2014. [Online]. Available: [Accessed: 30- Jun- 2021]
  2. 2.0 2.1 2.2 R. Mohamed, “Free CAD Designs, Files & 3D Models | The GrabCAD Community Library”,, 2021 [Online]. Available: [Accessed 29-Jun-2021]
  3. 3.0 3.1 3.2 D. Phan, “Free CAD Designs, Files & 3D Models | The GrabCAD Community Library”,, 2021 [Online]. Available: [Accessed 29-Jun-2021]
  4. 4.0 4.1 MisterBotBreak, "How to Use Temperature and Humidity (DHT) Sensors", Arduino Project Hub, 2019. [Online]. Available: [Accessed: 29- Jun- 2021]

Virtual and Actual Prototype Demo

The video below demonstrates the motor and fan components working:

The following video is the UI display. It shows the manual and the automatic function:

This video shows a step by step tutorial of the EneRec dryer

This video shows the menu page of the EneRec Dryer-

This video shows the state of the LCD when the drying is in progress-

This video shows the sound made by the buzzer-

This video shows the state of the LCD when the drying process has completed-

The following video demonstrates the opening and closing of the door:

This video is a demonstration of the energy recovery dryer:

This video shows an animation of the drum drive spinning in two directions:

Live Chat

If you have any questions or would like to have a chat with us you are free to drop in at any time with the url provided below:

Day Time Presenter Presenter

JULY 12, 2021

2:15 - 4:25 Elisa Pan Glen Mair
4:25 - 5:45 Akshata Pathak Jessi Nguyen
6:45 - 9:00 Ranbir Sharma Sabir Shaikh

JULY 13, 2021

11:15 - 12:15 Parmiss Abedini Dean Fernandez
12:15 - 1:15 Visal Saosuo Haoting Bu
2:15 - 3:15 Akshat Gupta Elias Cardozo

Chat with us {}

Team Members

Elisa Pan

Documentation subteam and Team Leader

An engineering student who loves designing and coding. Throughout this project, Elisa was able to learn and explore more her interests. She contributed designing the website, assemblying drawings, providing the photoview 360 redering pictures. She also offered her hand for any solidworks issue.

Glen Mair Documentation subteam
Glen Mair
An aspiring materials engineer from Mexico with great hopes for the world. As a member of the documentation subteam, he is comfortable in team environments working with many people.
Visal Saosuo Electrical and Electronic subteam
Visal Saosuo
Hello World!! I hope everyone is doing well and fighting through this pandemic. My name Visal (Vee-Sal). As an EE subteam, my partner and I went through many challenges with the project. I actually love those challenges because I always learn new lessons once I figured out the solution. In the EE team, I mainly work on the programming aspect and a few circuit connections. This project is amongst the most fruitful projects since it taught me from circuit connection to project management and 3D modeling.
Haoting Bu Electrical and Electronic subteam
Haoting Bu
Hello everyone! My name is Haoting Bu. I am a member of Electrical and Electronic Sub-team. In our group, I worked on the connection of the circuit for different components on the breadboard and Arduino. In the process of doing the project, my teammate Visal and I faced a lot of difficulties. Although doing this project is full of challenges, we solved the problems together as a team and learn many new knowledges from these challenges, especially for the connection of the circuit. I love working with my partner and learn new things in this project!
User Interface
Ranbir Sharma

User-interface sub-team member

Ranbir is an engineering student from Mumbai, India. The capstone conference has given him an opportunity to apply his practical skills and knowledge in coding. With Capstone conference, he was able to get hands-on experience on how to build an effective code that runs the whole system. He has also significantly participated in designing different layouts of functions within a code and structural designs of electrical components. Moreover, he is excited to present his work with his teammates at the capstone conference.

Sabir Shaikh

User-Interface sub team

Sabir Shaikh

A passionate engineer who has always had a natural inclination to computers and thus wants to pursue a career in this field. From fixing WIFI at home or teaching my parents how to take a screenshot, he believes that computers is the way to revolutionize the world further. He also want to be an integral part in that movement that is the Digital age and can’t wait to explore in depth this beautiful field he has fallen in love with.

Akshata Pathak Structural subteam
Akshata Pathak

An enthusiastic engineer with great hopes of trying to make everyone's life easier. She loves CAD-related projects and looking forward to taking on some more upcoming design team tasks in the future. Team interaction is something that she learned from this project. It was a pleasure for her to work with an amazing team of peers and is looking for a great summer ahead.

Jessi Nguyen Structural subteam
Jessi Nguyen

An aspiring engineering student who loves designing, modeling on CAD software and is interested in structure and buildings. The project has taught her how to work with other people in a team, keep track of work and improve collaboration.

Parmiss Abedini
An engineering student who has passion about designing and modeling on CAD software. She aims to learn the engineering principles fundamentally and apply them in her future projects. She believes that the key to success in engineering projects is team interactions when all the experts share their ideas and knowledge. This project gave her the chance to enjoy interacting with motivated students as well as working on solid works software.
Dean Fernandez

Mechanical subteam

Dean Fernandez
A motivated up-and-coming engineer who loves designing and working on CAD-related software. If he learned anything about this project it is that he now know how to communicate different designs with a team that is working towards one goal.

picture of Akshat Gupta Mech subteam
Akshat Gupta

Mechanical subteam

Classy and energetic modern day engineer with a goal to promote sustainable and environmentally friendly technology in the future. The project taught this person how to work with a big team and function in a smaller team within the bigger team.

Elias Francisco
Mechanical subteam
Elias Francisco

An applied science student who wants to use his passion for engineering disciplines - specially designing and coding - to make a change in the world. Since the start of the summer term, he has been enthusiastic with the opportunity of working on his first engineering design project along with his teammates.