IMG 7804.JPG
FA info icon.svg Angle down icon.svg Project data
Type Clothes dryer
Authors Jacob Johnson
Radical Earth Solutions (RES)
Location Arcata, California
Status Deployed
Years 2009
Cost USD 238.27
OKH Manifest Download
Bamboo clothes drying rack

This page was created by Radical Earth Solutions (RES) Engineering design team on behalf of the DraftMaster appropriate technology clothes dryer design that was created in Lonny Grafman's Engineering 215 class at Cal Poly Humboldt (HSU). With Campus Center for Appropriate Technology (CCAT) as the client, RES was hired by CCAT to produce a new clothes dryer technology to replace CCAT's previous clothes drying technology to a more efficient, durable, low maintenance. After an extensive design process, in one academic semester (12 weeks), RES produced the DraftMaster appropriate technology clothes dryer design for CCAT to use, display, and demonstrate in the CCAT house.

Background[edit | edit source]

CCAT was dissatisfied with their current clothes drying technology and requested RES produce a new clothes drying technology. CCAT's past clothes drying technology (as shown to the right) consisted of draping wet clothes from the clothes washer onto a bamboo drying rack and allowing the clothes to dry ambiently. The bamboo rack drying technology did not effectively dry CCAT's clothes before mildew accumulated. RES's objective was to produce a new and effective appropriate technology clothes dryer, meeting CCAT's requirements and concurring with CCAT's mission statement.

Criteria[edit | edit source]

After alternative solutions were created, criteria for the final design was formulated and weighted from CCAT input, output, and solution variables. The alternative solutions were then judged to choose a final design.

Criteria Weight Constraints
Safety 10 Must be safe for operator and clothes
Usability 10 Ease of use, reusable and consistent
Construction Practicality 10 Must be able to build with limited time, resources and tools
Efficiency 9 More than or equal standard dryer
Durability 9 Must be able to handle everyday use
Maintainability 7 Must be able to be cleaned and not tedious
Aesthetics 6 Non-intrusive (as defined by CCAT)
Operational Cost 5 Less than a average
Building Costs 2 Greater than or equal to washer size load
Capacity 2 Equal or greater than CCAT clothes washer load

Criteria Definitions

  • Safety – Must pose no harm to the operator, the clothing, the system or the surroundings.
  • Usability – The effort required by the operator to consistently use the final solution every time.
  • Construction Practicality – The feasibility of the final design to be built within the given constraints.
  • Efficiency – The amount of energy that is required in order to run the system proportional to the amount of clothes dried.
  • Durability – The projected ability to maintain performance over time.
  • Maintainability – The amount of time necessary to clean and set up the essential parts required to function.
  • Aesthetics – The amount of visual appeal.
  • Operation Cost – The monetary cost required to operate the final solution.
  • Building Cost –The initial production cost of the final solution.
  • Capacity – The amount of clothes that the dryer can handle per use.

Final Design[edit | edit source]

Final Design Description

The DraftMaster design incorporates airflow and low energy to dry clothes. The design body is cabinet shaped with four open sides, a closed base, an open top, and is made entirely of stained and sealed wood. Plywood panels encase the base and top sections of the body. The top of the design contains two 20" box fans facing downward. Directly below the box fans is a dowel rack to hang clothes on conventional clothes hangers. The purpose of the box fans is to push air through and passed the clothes to remove moisture from the clothes. The box fan power cords are plugged into a timer that controls the time the fans are in operation. The open sides of the DraftMaster design are utilized to maximize airflow and evaporation of water molecules and minimize air friction and back draft of the fans. The purpose of the base is to add stability to the design body. At the bottom of the base are four locking-caster wheels. The purpose of wheels on the design is to facilitate feasibility of design mobility.

Final Design Operation Instructions

To implement the DraftMaster design, the design should be located in a room able to withstand increased humidity levels and is supplied with a standard AC outlet. The design performs optimally when the sides and the top of the design are not blocked by other objects; therefore, the design should be located away from other objects.

To operate the DraftMaster:

  1. Hang wet clothes from clothes washer, immediately after the clothes washer's wash cycle, on conventional clothes hangers. Hang the conventional clothes hangers, with clothes, on the dowel rack.
  2. Plug the box fan power cords into the timer, if not already completed.
  3. Turn on timer to desired time.
  4. Return to DraftMaster after timer shuts off and remove clothes.

Costs[edit | edit source]

Item Qty Price per unit item Price paid for qty of items Total
Plastic Locking Caster Wheels 4 $2.99 $11.96 $13.04
Wood Patch Latex (wood putty) 1 $4.99 $4.99 $5.44
Cherry Wood Stain 1 $7.99 $7.99 $8.71
Wood Varnish 1 $15.99 $15.99 $17.43
Sanding Disc 180 Grit 1 $4.79 $4.79 $5.22
Sanding Disc 120 Grit 1 $4.79 $4.79 $5.22
Grounding Receptacle 1 $0.79 $0.79 $0.86
Receptacle Plating 1 $0.47 $0.47 $0.86
Electrical Outlet Box 2 $4.29 $8.58 $9.35
Romex Electrical Wire Connector 4 $2.29 $9.16 $9.98
Toggle Switch Wall plate 1 1.79 1.79 1.95
20" Box Fan 2 $19.99 $39.98 $43.58
Dowel Rod Holder 1 $2.50 $2.50 $2.73
Blank Wall plate 1 $1.34 $1.34 $1.46
Power Cord 1 $8.99 $8.99 $9.80
12 Hour Timer Switch 1 $22.99 $22.99 $25.06
Box 1/4" Cable Staples 1 $4.04 $4.04 $4.40
3" Paintbrush 2 $1.70 $3.40 $3.71
2" Paintbrush 2 $1.25 $2.50 $2.73
4' Wooden Closet Rod 1 $3.56 $3.56 $3.88
2' x 4' x 8' Douglas Fir 7 $2.40 $16.80 $18.31
1/2" 4' x 8' Plywood 1 $35.65 $35.65 $38.86
1 1/2" Wood Screws 50 $0.04 $2.13 $2.32
Total (with tax) $238.27

Next Steps[edit | edit source]

The next step to modify the DraftMaster is to observe the DraftMaster's effect on the rooms of CCAT. If no moisture problems arise from using the DraftMaster without ducting then the design is complete. If problems arise in CCAT because too much moisture is being ejected into the room by the DraftMaster then casing, ducting and/or moisture control modifications need to be made to the design.

October 2014 Update[edit | edit source]

Updated by Jacob Carroll-Johnson and Carlos A. Sanchez

The integrity of the DraftMaster has not been compromised. It works just as well as the initial use. There are no signs of degeneration in the wood from moisture. No parts have been fixed, needed to be fixed or need to be fixed or replaced. The structure and components of the DraftMaster are sound.

The problem with the DraftMaster is the length in which it takes to dry clothes. Drying clothes with the DraftMaster takes over 2 hours. Even after that time the clothes will still be damp, it does not dry clothes thoroughly and the clothes will have to be left to hang up overnight (which just can be left on the DraftMaster itself). The DraftMaster as stated early on this page is supposed to be used outside due to moisture levels increasing. The DraftMaster, however, is rarely used outside. Partly due to lack of knowledge and literature such as a sign to take it out for use. Another larger reason is the DraftMaster's larger size. The design of it is not sleek or slender or very easy to move even though the wheels do help, people just don't want to take it out. I had a hard time moving this outside just to take pictures of it. Detriment from moisture level to surroundings from use inside is not known but has no noticeable impact when used inside. If insistent upon using inside use in conjunction with a humidity meter if humidity levels rise to high stop use. The top of it sometimes gets clothes stored there without others knowing this. This causes the fans not to be able to circulate air which gives DraftMaster an appearance of being broken. It is rather tall so seeing that the fans are blocked at the top is not easy nor apparent.

To break this update down; be patient in waiting for your clothes to dry, use outside and do not sit anything on top of the DraftMaster. Follow those three simple rules and you will have superb experience with the DraftMaster.

Cookies help us deliver our services. By using our services, you agree to our use of cookies.