Inside a 70-Year-Old HVAC Business’ Strategy to Build Generational Trust

Recently, Steve Dennis, president of Newark, DE-based Schlosser & Associates, visited with Glenn Slonecker, senior facilities manager for the spacious Siemens Healthcare Diagnostics campus in Glasgow, DE.   

The two of them share the bond of friendship, both personal and professional. Their relationship spans a quarter of a century; Glenn has served Siemens for 52 years. During that time, all three of Steve and Garnet Dennis’ sons have spent time working at Siemens under the tutelage and mentorship of Slonecker and others at Siemens.   

Steve and Garnet co-own Schlosser & Associates, a full-service mechanical contracting firm in Delaware. Last year, their firm celebrated 70 years in business. Today, Steve and Garnet represent the second generation of family ownership; their sons, the third, fulfilling a legacy that has adapted, expanded, and thrived for more than seven decades.  

It’s easy to see that the comfortable, easy relationship between Steve Dennis and Glenn Slonecker is one based on long familiarity, mutual trust, and respect for the contributions of the other. Their conversations typically shift between shared recollection and work successes.   

The family-oriented culture at Schlosser & Associates is further showcased through the commitment of the company’s owners to their associates — not “employees” — most of whom have been with the firm for decades. It’s a distinction that, by design, emphasizes tenure, commitment, and collaboration. Currently employing 46 associates, the firm is dedicated to creating a supportive workplace — evident in their generous employee benefits, exceeding industry standards.

“We rarely struggle with turnover,” said Steve Dennis. “It’s truly a blessing. As a result, we often get referrals for candidates to fill positions here. We’ve developed our workforce through the Delaware Apprenticeship program and also have deep roots in the communities we serve.”   

It helps that he and other staff members serve in volunteer roles locally and regionally. Steve   Dennis was recently named president of the Delaware Contractor Association, a group that serves both union and non-union members.   

Schlosser & Associates is a non-union shop that does mostly commercial work, providing a broad mix of skills for commercial, industrial, and residential customers across Delaware, Maryland, and Pennsylvania.   

Steve Dennis says that, currently, their efforts consist of 60% commercial work, 20% industrial, and 20% light commercial and residential service work. The firm offers a diverse suite of services, including HVAC, hydronic, plumbing and process piping, structural steel, concrete work, basic carpentry and painting, and indoor air quality solutions.  

Steve and Garnet’s young adult sons are now well on their way to assuming leadership roles within the firm. Their youngest, Justin — who worked at the Siemens site for six years — is now a commercial estimator. Zach, now operations manager at the firm, worked for Glenn Slonecker at Siemens as a quality engineer until February 2024. Chris, who also enjoyed his time at Siemens under the guidance of Slonecker, now serves Schlosser & Associates in the field as an estimator.        

Jobsite Success 

Steve Dennis confirmed that other facets of their work add to the company’s stability. They’ve more or less standardized on a recipe, including the products and technology they install. Favored technologies include Bryan steam boilers, Evapco cooling towers, Trane chillers, Air+ air purifiers, Metalair VAVs, Innovent and VTS, air handlers, and Watts backflow assemblies (Steve and several others within the company maintain their backflow certifications); Taco manufactures the pumps, circulators, and hydronic components of choice.   

“When things work well — or don’t — we shift to other products, improve, learn, and sharpen our skills,” added Steve Dennis. “We’ve learned a lot through decades of careful management.  When you’re in the business for the long term, as we are, it’s rather amazing how that sharpens our focus on maintaining the success, reliability, and predictability of our work.”    

There’s no better way to examine a company’s dedication to craft than to look at examples of their work. Clearly, every project is different, though Schlosser & Associates’ managers have found that certain facets of their performance — from how they work as a team, how they integrate with other trade pros on jobsites, and the tools and equipment they reach for routinely — all have an impact.   

Siemens Health Care Diagnostics 

At the sprawling Siemens campus just south of Wilmington, DE — once one of the main sites for DuPont — there are several buildings, some of which include laboratories and clean rooms requiring very specific air quality requirements. Here, working in concert, Steve Dennis and Siemens’ Glenn Slonecker — among many others — maintain a complex network of advanced mechanical systems.      

According to Slonecker, there’s a mile of subterranean 18-inch supply and return fiberglass pipe on campus, connecting chilled water to facilities for space conditioning, and specific process needs, many of which require tightly-controlled dehumidification, allowing the presence of atmospheric moisture at levels of 0-10%. That’s dry.

“We test a lot of medical products and diagnostic consumables,” explained Slonecker. And because their 1,000-plus employees on campus are working two or three 8-hour shifts each day, there’s little or no downtime. Mechanical systems that provide and distribute chilled water play a key role in maintaining full operational status, and redundancy is important. 

On campus, there’s a 1,500-ton Trane chiller connected to a similarly-sized dual-cell, AT induced draft, counterflow Evapco cooling tower. In fact, nearby — serving similar needs — are 550-ton, 450-ton, and 350-ton chillers, all working in tandem with Evapco cooling towers. A few years ago, Slonecker made a trip to Evapco’s headquarters in Taneytown, MD, with Chris Delp, sales engineer, and other members of the rep firm that serves them, West Chester, PA-based Energy Transfer Solutions (ETS).   

At the Siemens site, there’s also a complex network of domestic and process water piping that serves the many facilities there.  Surprisingly, most of the water comes from groundwater wells on site.  Well water is pumped into a 400,000-gallon holding tank; distribution piping runs from it to all campus facilities.  

Slonecker said there are 20 or 30 backflow assemblies installed and routinely maintained and tested to guard against the risk of backflow. All of them are manufactured by Watts in 2, 3, and 4-inch configurations.

Kirk Middle School 

The Kirk Middle School is a public school located in Newark, DE, serving 740+ middle-school students in grades six to eight in a large, suburban setting.   

According to Schlosser & Associates President Steve Dennis, Kirk School now has three 165-ton cooling towers that are used for comfort cooling throughout the school. He added that Schlosser has worked for the school district for four or five decades.

Cory Marshall, Schlosser’s commercial projects manager, has served the firm for more than 40 years. He supervised the work at Kirk Middle School.   

“Backflow assemblies are crucial for preventing contaminated water from entering the public water supply, protecting public health, and ensuring compliance with regulations,” said Steve Dennis. “They act as one-way valves, stopping water from flowing backward into the clean water system, which can occur due to pressure changes or other factors. 

“We’ve standardized on Watts backflow assemblies,” he added. “Our performance on the job, and the trust we establish in building business relationships, depends not only on the quality of our people, but also on our expertise and reliability. We’re in the business for the long haul, and that places important dependence on the quality of products and services we provide.”