Meet Our Team

The knowledge and skills of our employees set Century Mechanical Solutions apart from other mechanical contractors. We are proud of what they contribute every day to put our customers’ needs first. They enable us to find the best solutions to help you accomplish your goals.


Thomas Lienhart, PE, President
Tom has been the President of Century Mechanical Solutions Inc. for more than 25 years. He is responsible for overall business strategy including financial planning and management.Tom is the primary design engineer responsible for development of industrial and commercial Heating Ventilating Air Conditioning and Refrigeration. He maintains professional engineering licenses in Ohio, Kentucky and Indiana, as well as the relevant contractor’s licenses in Ohio and Kentucky.

Tom has fostered professional relationships and affiliations with the leading organizations in the industry: ASHRAE, IIAR and ICC. Tom serves on the Cincinnati Fire Department Appeals Board. He is also a member of a CEO Roundtable in Cincinnati.

Kenneth Weller, Vice President
Ken started with Century Mechanical Solutions Inc. in 1977 and is currently the Vice President/General Manager. He is responsible for overseeing the daily operations of the company and for assuring that we provide the top-quality services for which we are well known.He has a strong background in HVAC service and design-build projects. He is available to assist you with any aspect of your HVAC needs.
Margaret Lienhart, Secretary and Treasurer
Marge has been the Secretary/Treasurer of Century Mechanical Solutions for more than 30 years and is responsible for Information Technology. Marge has a strong background in digital controls and has successfully completed manufacturers’ training.She is the ASI Controls liaison. Her work includes programming, designing user interfaces and setting up networks.

She has completed successful building automation projects, including a 250,000 square foot paper manufacturing plant, a LEED building, and tightly controlled products warehouses.

Marge aims to make building automation user friendly by taking the time to create simple graphic interfaces, customized user manuals, operator training and product support.


Service Department

Douglas Ruehl, Service Manager
Doug Ruehl is Service Manager and has worked at Century Mechanical Solutions since 1984. He has more than 25 years of HVAC experience, including working with, companies such as Proctor and Gamble, L’Oreal and the JM Smucker company.At Century Mechanical Solutions, Doug leads a staff of more than 30 technicians who provide our customers with 24-hour emergency services. Doug’s responsibilities cover the entire range of company services from preventative maintenance proposal development to service delivery.

Doug has extensive field service experience and carries a journeyman’s license, universal recovery license, OSHA certification as well as continuing education from our manufactures and suppliers.

Jean Dougherty, Service Assistant



Douglas Niehaus, Senior Sales Engineer 
Doug is a Senior Sales Engineer and has been a key member of the design team at Century Mechanical Solutions Inc. since 1986.He has more than 35 years of commercial and industrial refrigeration and HVAC experience. Doug worked as a service and installation technician / foreman early in his career and is very knowledgeable in the technical side of the business. Doug’s work at Century Mechanical Solutions Inc. includes supporting companies like Kahns, Sara Lee Foods, and Southern Belle Dairy.

Doug has helped design, maintain, and service large refrigeration projects throughout the country. His duties includes sales, design, selection, and overseeing projects involving chillers, compressors, boilers, industrial and process piping, ammonia and  freon refrigeration.

Darlene Rogers, Accounts Receivable
Larry Sawyer, Sales Engineer


Project Management

David Diedesheimer, Project Manager
Dave is a Project Manager and has been an integral member of the installation team at Century Mechanical Solutions since 1987. He has more than 20 years of HVAC experience.During the past five years, Dave has joined the management staff and now handles scheduling of all the installers as well as oversees the progress of large complex projects.

Dave holds a journeyman license, completed manufacturer’s training and 30 hours of OSHA safety training.

Thomas Nieman, Project Manager
Tom is a Project Manager and has been an integral member of the design team at Century Mechanical Solutions since the early 1990s. He has more than 20 years of HVAC experience.Tom has helped install, operate and maintain all kinds of HVAC projects. This includes installing and servicing equipment like boilers and rooftop units as well as demolition and construction of process piping.

He holds a journeyman license, completed manufacturer’s training and holds OSHA safety training.