NSF-Funded Student Design Projects:
HVAC Disassembly Process and Workstation Design

Designers: Tomica S. Champion and Claudia Ricaurte
Client Coordinator: Ms. Jane Resutek, teacher, Warren Woods Towers High School; Mr. Jim Resutek, Engineer, Delphi
Supervising Professor: Robert Erlandson, Ph.D.
Department of Electrical and Computer Engineering
Wayne State University, Detroit, MI 48202

INTRODUCTION
The objectives of this project are two fold: 1) create new job opportunities for special education high school students, and 2) demonstrate that the recycling of damaged heating, venting, and cooling (HVAC) units can be cost-effective. Students in this program are classified as learning disabled and/or educably mentally impaired. Students disassemble the units and store the parts.  This experience allows them to gain technical skills and prepare them for the automotive workforce.  It also teaches them general work skills such as following instructions, working with a supervisor, and working as a team player. In the automotive industry, most corporations are trying to create a  "greener" environment by recycling, refurbishing, and reducing waste. These are the corporate goals of the participating automotive supplier and assembly plants; their altruistic goal is to help the disabled population.

Various HVAC units are supplied to a number of assembly plants, where they are installed in a variety of cars and trucks.  HVAC units are often damaged during shipping and assembly handling.  Both the HVAC supplier and the assembly plants want to salvage the usable components, but it is not cost effective for them to inspect each unit to determine which components are salvageable.  Prior to this project the damaged units were discarded.

Mr. Resutek made a presentation to corporate officials proposing a model wherein the HVAC supplier and the respective assembly plants donate the damaged HVAC units to the Warren Woods special education program. The donated value of the damaged HVACs would be split between the supplier and assembly plant.  A hauler volunteered to collect the damaged HVAC units from the assembly plants and deliver then to the high school.  The special education students would then disassemble the units and separate the components.  Some components were fully operational subsystems such as fans, a heater core, and an evaporator.  Other components were brackets, screws, nuts, and bolts.  Lastly there was the large plastic frame.

The functional subsystems can be inspected, warranted, and sold as used equipment for automotive repair shops.  The screws, nuts and bolts are recycled at the supplier facility.  The plastic material could be chipped and sold for further recycling.  Since the students are working as part of their educational training, their payment is strictly regulated.  Hence, the combination of regulated low student wages, donated equipment and hauling services, and a market for the sale of harvested components produce a workable economic model.

Warren Woods High School did not have a workstation suitable for the disassembly process.  The school needs a safe and ergonomically correct work environment to disassemble HVAC units while accommodating the disabled students.

The HVAC Disassembly Process and Workstation Design project combines the simultaneous efforts of process design, workstation design, material flow, and facilities layout for the entire disassembly process from incoming product to output of the final harvested parts.  The project’s objectives are to:  1.) develop and build an efficient and safe workstation layout; 2.) develop and implement an efficient and orderly storage area; 3.) develop and build an efficient and safe material handling system.
 

SUMMARY OF IMPACT
Figure 2 shows the completed prototype workstation. This workstation is part of the designed disassembly process.  It is housed in the school’s receiving room that has a door leading to a loading dock.  The project developed plans for long term storage system for delivered HVACs and harvested components.  The project finished in May 2001 and the workstation delivered to the school in June 2001.  This was too late for actual student use during the current school year.  The workstation field-testing will start in September 2001.  Since the workstation is a critical element it was deemed necessary to validate its design before proceeding with the storage and material handling elements of the project.
 

TECHNICAL DESCRIPTION
The project objectives are to: 1) create realistic, real world jobs for the vocational training of high school aged special education students, 2) create a work process wherein the students could work as independently as possible, 3) create a process that is safe and ergonomically sound, and 4) demonstrate the viability of the recycling model as a greener and yet cost-effective mode operation.

A quality function deployment (QFD) model was used to assess and prioritize the client’s wants.  The client’s wants are: student independence, ergonomics, cost effectiveness, and inventory control.  The technical requirements are: process disassembly design, workstation design, material flow design, and facility layout design.  Using the QFD approach the customer’s wants were assigned a weight. For this project the weights were: student independence 40%, ergonomics 30%, cost effectiveness 25% and inventory control 5%.  Using QFD these weights were then related to the technical requirements and a priority ranking established for implementation of the technical requirements.  That priority was workstation design first, disassembly process design second, followed by material flow design, and lastly facility layout design.

Based on this analysis, work proceeded on the workstation design and disassembly process design.  These two elements were seen as closely linked in that the workstation design must support the disassembly process.  There were five different HVAC units, each a different size and weight and with different harvestable components. However, there was considerable similarity between HVACs, which allowed for a usable generic disassembly procedure.  Based on this disassembly procedure and worker ergonomic needs that included wheelchair accessibility, the workstation was designed and assembled.

The workstation was built from Creform, a pipe and joint agile device technology. The pipe and joint technology allows for rapid proto-typing yet is strong enough to be used for the final product.  Creform is heavily used throughout the automotive industry.

Figure 2 shows the completed mobile workstation.  The station is wheelchair accessible, yet it allows non-wheelchair users to work comfortably.  There is an overhead rack for support of disassembly tools and fixtures. A counter balance will support a power drill so that the worker does not have to accommodate the weight of the drill while involved in disassembly. There are two mobile, detachable side carts with slanted racks. One will hold the HVACs and the other will hold the harvested parts in plastic containers placed on the tilted cart rack.

A facilities layout was provided along with suggested material flow and storage suggestions. These were preliminary and will be subject to re-evaluation in a subsequent project.