top of page


For over 50 years, we have been one of the Washington Area’s most respected and trusted Mechanical Contractors


We are a full service heating, air conditioning, refrigeration and process piping company strategically located in Brentwood, Maryland. We work with the Government, building owners, general contractors, engineers, architects and property management companies to develop, furnish, install, service, repair and maintain all types and sizes of commercial and industrial mechanical systems. Highly trained and skilled, our workforce provides quality work with integrity allowing you to meet your budget and functional requirements on time, every time. We use our knowledge and expertise to make sure your business never stops due to mechanical failure. Our team of driven employees include Journeymen Steamfitters, HVACR technicians, Project Managers, Certified Welders, Apprentices, Helpers and a highly motivated team of Administrative Personnel. Our continued success attests to the quality, capability, and consistency of our work, instilling you with secure knowledge that their projects are in the hands of one of the most respected contractors in the Metropolitan DC area. 

Our preventive maintenance programs extend the life of HVAC Systems and ensure peak operating efficiency, saving you downtime and money. To save on utility bills and service calls, we urge you to take a preventive approach to heating and cooling. We offer a quality preventative maintenance program designed to meet the specific need of your business. We will maintain your system for you even if it was not installed by our company. Our maintenance program ensures the best performance and lowest operating costs from your heating, air conditioning or refrigeration system. The program allows our technicians to spot any trouble before it becomes a costly repair job. This results in fewer breakdowns and extending the life of your equipment. Please call for a quote today! Whether you are an owner, Property Manager, General Contractor, or the Federal Government, whether you need installation or service, our goal is to provide you with key environmental systems expertise. You should be at ease and in control — a feeling of confidence and comfort that we are happy to help you establish and maintain.


  • Commercial Industry

  • Government Buildings

  • Property Management Firms

  • Apartments

  • Churches

  • Shopping Centers

  • Schools

  • Mission Critical - Data Centers / Computer Rooms

  • Office Buildings

  • Laboratories

  • Industrial facilities

  • Hotels

  • Hospitals

  • Tenant Fit-outs

  • New Construction & More!



A family owned and operated business, Interstate Service Company was established by James Ashen in 1972. Although he is still involved with the firm, Mr. Ashen is proud to have recently passed his legacy on to the next generation. Today his daughter and son, Heather D'Jangali and Kenneth Ashen operate and manage Interstate Service Company.  They are looking forward to growing the company in the years to come while maintaining their father's dedication, passion, excellent customer service and unsurpassed reputation.



Kenny Headshot.jpg

Kenny Ashen

Vice President

Kenny Ashen began his career at Interstate Service Company learning the trade as a summer helper at the age of 15. Upon completion of a 5 year apprenticeship program, Kenny graduated in the upper tier of his class from the Steamfitters UA Local 602 Trade School as a Journeyman in 1993. During his extensive 35 years in the HVACR business, he has performed all facets of the operation including troubleshooting, service, maintenance, dispatching, construction, estimating/project management, design and installation. Given his huge percentage of repeat business, Kenny takes pride in his work, ensuring that each project is completed with his specific clients needs in mind, within budget and on time...every time. Kenny has rightfully earned his trusted reputation in the Washington Metropolitan Area as one of the most trusted top Mechanical Contractors.

Heather D'Jangali


Heather D'Jangali has been with Interstate for 25 years, working her way through the company holding multiple positions and enthusiastically contributing her multi-faceted skills to provide solutions to business challenges. An entrepreneur of multiple diverse businesses and a true leader, Heather is a strong believer in creating opportunities, challenging herself, and following her passion. Heather's background in management, finance, sales, marketing and customer service has contributed greatly to the success of the organization. Heather is a "people person", knows the value of exceeding client and employee needs, the importance of attention to detail, is exemplary in customer service and thoroughly enjoys running the day-to-day operations. Heather served on the Safety Committee for the Mechanical Contractor's Association of Metropolitan Washington for 15 years, is an active member of the Women Presidents' Organization and takes pride in giving back to the community through discussion panels, speaking engagements and participating in other events. During her years in a male-dominated industry, she has overcome many obstacles, proven herself, adapts well to change and continues to bring new perspectives and fresh ideas as she leads Interstate Service Company into a new era.

Heather headshot 1.jpg
_joy0156 copy_edited.png

James Ashen


Steve D headshot.jpg

Steve Dwyer

Project Manager

_joy0139 copy_edited.png

Robert Brown

Service Manager

James Solano headshot.jpg

James Solano

Construction Supervisor

Diane favorite Headshot DSC_3412.jpg

Diane Gilliam


Renee headshot.jpg

Renee Marks

Payroll Manager

Kiisa headshot.jpg

Kiisa B.

Administrative Assistant

Amanda headshot.jpg

Amanda Biesel

Accounts Receivable Manager



Operations and Maintenance

Providing full-service maintenance, with dedicated staff to ensure uninterrupted systems operation and quick repair. Maintenance of all types of systems, including equipment that was not installed by our company. The emergency service team is available on call 24/7 for our contract customers.

Systems Design, Project Management and Installation

ISC provides full and partial HVAC system replacement, tenant fit outs, renovations as well as brand new ground-up installations. Specialists in retrofitting older buildings with new heating and cooling systems.

Mustang Sally Brewery.jpg
Commercial Refrigeration

Installation and service of all types of commercial refrigeration units, including walk-in coolers and freezers, reach-in boxes, and ice machines.







For any inquiries, questions or commendations, please call: 301-864-2121 or fill out the following form:

Thanks for submitting!

Head Office

4101 Utah Avenue
Brentwood, MD  20722



Tel: 301-864-2121

Fax: 301-864-1282

bottom of page