821 E. Lincoln Hwy. DeKalb, IL. 60115 • 1010 Jorie Blvd., Suite 390 Oak Brook, IL. 60523

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Accurate size, maximum efficiency

Take the guesswork out of your heating or cooling needs by counting on our team's innovative load software to deliver accurate calculations on equipment sizing to maintain your system's best performance.

Our size calculations protect your wallet and home comfort

We prefer not to guess as to which size of equipment will be needed to efficiently heat or cool your space. We will measure your home or business and properly calculate your heating and cooling load. 1 Source Mechanical will enter all the pertinent information in our load calculation software and determine the proper size equipment. We will provide a heat loss and heat gain report for you to see.

Your source for HVAC solutions

You've got your accurate size calculations, now it's time to do the work and watch your residential or commercial property reap the rewards of top-notch HVAC products and services. Get an estimate for your service or installation today.

Is your boiler as efficient as it could be?

Are you not maximizing the performance of your furnace or boiler? Improper size could be the issue - let our experts get you the answers you need with an affordable combustion analysis. You never have to wait for answers when

you call us!

- Free Estimates

- 24/7 Emergency Service

- 100% Financing Available

- All Repairs 1 Year Labor Warranty

- Fully Insured, Licensed and Bonded

Why choose us?

Get your system's sizing needs taken care of with a FREE estimate..


1 Source Mechanical Inc. is your locally owned and trusted heating, air conditioning, plumbing, and refrigeration contractor. We serve all of DeKalb County and the surrounding areas including all of DeKalb, Sycamore, Genoa, Malta, Sandwich, Cortland, Hinckley, Kingston, Kirkland, Aurora, Elgin, Maple Park and Elburn.