Our Team
Robert Heiderscheidt, President and CEO
Robert Heiderscheidt is a 27-year veteran of the electrical industry with a core concentration in telecommunications infrastructures. He founded MDI Electrical Construction in 1992. Under his guidance, the firm enjoyed steady growth. With the divestiture of the Bell monopolies, exploding internet growth, and MDI’s concentration in telecommunications infrastructure, Heiderscheidt subsequently founded MDI Access in 2001 as a design/build GC firm specializing in switch rooms, colocation facilities, and data centers. In addition to his duties as President & CEO, Heiderscheidt continues to focus on company expansion and design of the larger data center projects.
Prior to founding MDI, Heiderscheidt attended St. Mary’s University with a concentration in business administration and computer science. He spent four years in the IBEW Local 134 apprenticeship program, where he graduated top of his class. Heiderscheidt spent the next four years working for various electrical contractors as foreman, general foreman, superintendent, estimator and project manager. He is an active member in NECA (National Electrical Contractors Association), Alsip Industrial Association, Alsip Chamber of Commerce, BICSI, LEED, and the AWEA (American Wind Energy Association).
Mark Untiedt, Chief Operating Officer
Mark Untiedt is a highly-qualified construction industry executive and LEED-certified architect with over 18 years of professional experience. During his career, Untiedt has executed and managed everything from large, ground-up mission-critical facilities to small office build-outs. Prior to joining MDI Access, Untiedt worked as a consultant with Cubellis (Chicago) and also with Carlson, a leader in the tech explosion of the late 90's and early 2000's with clients such as Genuity (GTE), MCI Worldcom, Level 3 Communications as well as other mission critical facilities such as FOX Television Network and AskyB.
While working as a consultant for Cubellis on a host of local projects with MDI Access, Untiedt recognized the quality of work and potential that MDI brought to the telecommunication industry and was eager to join the management team. As a LEED certified architect, Untiedt also embraced the energy efficient designs of MDI Access and their investment into alternative energy projects.
Christopher Krestel, Chief Business Development Officer
Christopher Krestel is a licensed architect and project manager with over 10 years of professional experience. Krestel has managed multiple simultaneous projects with a wide range of project scope, organizing multi-disciplined teams and serving as the main client contact for projects across North America.
Krestel’s passion is utilizing the latest in technology to improve the design process, improve our clients understanding of the built environment and improve the bottom line. He was instrumental in introducing Building Information Modeling (BIM) within Cubellis & Loebl Schlossman & Hackl. Krestel also embraces the energy efficient designs of MDI and their investment into alternative energy projects.
Krestel is an NCARB-certified, licensed architect and interior designer and holds professional membership within the AIA. He is also a member of the Village of Mokena, Site Plan and Architectural Review Committee, donating his time and abilities for the good of the local community.
John Heiderscheidt, Chief Compliance Officer
John Heiderscheidt is the Chief Compliance Officer for MDI Access. He is also a licensed attorney and telecommunications real estate broker. John’s primary focus is ensuring all of MDI’s projects meet compliance standards across multiple jurisdictions and venues. He personally reviews all contractual and legal documents impacting the company. He is heavily involved in data center site selection and acquisition for MDI as well. John is the primary point of contact for all cryptocurrency customers who host their miners with MDI or MDI partner properties.
Prior to joining MDI, John operated a law office providing corporate and criminal defense litigation services. He has argued before different courts and tribunals across Illinois.
Bob Matthews, Vice President of Sales
Bob has 42 years of experience in mission critical applications and has an extensive track record of product knowledge, application, successful project execution and delivery. Bob Has always been a technical sales consultant and has overseen thousands of projects from just about every company on the Fortune 500 list. His operational leadership, project management, technical expertise, and the ability to manage risk has helped produce some very rewarding projects.
Tim Mandell, CRO
Tim, a 1993 graduate of Purdue University, West Lafayette, Indiana, has spent his career in business-to-business sales, management, and executive roles. Mr. Mandell entered the business community with a sales position for a copier company.
After leaving the copier industry, he took a position as District Sales Manager with G&K Services an industry leader in uniform and facilities services. He was recognized as a Spirit of Excellence manager in 2002, ranked second out of sixty-five sales managers. He also was involved as a corporate sales trainer and as a mentor for new sales managers, sellers, and underperforming markets.
Mr. Mandell joined the Geneseo Communications group as Chief Operating Officer for GenSoft Systems, Inc. in January 2010. He developed programs to address the issue of the telecom industry revenue loss and customer retention with unique revenue sharing opportunities. While at GenSoft he was able to increase top and bottom-line revenue while reducing the redundant workforce by 40%. He later also assumed the role of Chief Marketing Officer for the organization and was responsible for the growth and management of Geneseo’s ColoHub data center.
In 2021 the data center sold to Bluebird Networks, and he retained his position. Focusing on traditional server hosting and cryptocurrency hosting he achieved 517% of his revenue goal in 2021. He joined MDI Access in May of 2022 working on the development of the organization’s facilities and offerings while expanding the customer base.
Michael Mulholland, Senior Sales Executive
Michael, a Desert Storm Air Force veteran and a 1997 cum laude graduate of Saint Ambrose University in Davenport, Iowa has enjoyed success in various sales roles within technological industries.
Michael’s most notable accomplishments include a Sales Excellence award from Medline by growing his territory by over 400% during his 5-year tenure. In 1998 he achieved IKON Office Solutions President’s club for achieving 125% of goal. He also consistently ranked in the top 2% of sales executives nationally for a Fortune 50 organization.
Mr. Mulholland’s has been instrumental in leading and developing new markets within several organizations. He has developed a unique ability to utilize a company’s core competencies to develop new sales channels while maintaining the highest level of value and customer service to his clients.