Skip to content
OSA Heating & Cooling LLC BBB Business Review
Call Us At (203) 338-0371

Professional heating & air conditioning services in Lower Fairfield & New Haven Counties

OSA Heating & Cooling has been in business for 20+ years. Our company’s number one priority is to offer superior heating and cooling installation, HVAC preventative maintenance, air conditioning and heating repairs, indoor air quality and duct work service.

Our versatility ensures that we are able to meet any of your residential or commercial heating and cooling requirements. We are dedicated to providing unparalleled service to all of our customers in Lower Fairfield and New Haven Counties. To meet the needs of our customers, training at OSA Heating and Cooling is an intensive and on-going process.

The end result is that you receive prompt and efficient service delivered with the utmost professionalism - the first time. That’s what sets OSA Heating & Cooling apart from our competitors.

Our trained specialists are dispatched from our local office, and are always just a phone call away. This ensures prompt, immediate responses to all situations.


  • Collecting permits for businesses and residents
  • Installation - Repair and service of every major brand
  • Personalized HVAC work
  • Estimations free of charge


I called OSA on Sunday and was told a service technician would call me directly. Ten minutes later I received a call from Pablo and things really started to happen...explained everything and kept us posted each day.

Paul & Diane M

This is my go to place for any Heating and Cooling work. I would recommend them to anyone, especially family. They treat customers with respect and like family. Their work is great as well as customer service.

Devang D.

OSA's technician resolved the issue ASAP in a neat and timely fashion. Plus he was early. 

Samantha M

Preventive Maintenance
Indoor Air Quality
Residential Heating & Cooling
Oil to Natural Gas Conversion

Areas we service

Technician checking compressor amps

6 Maintenance Tips to Prepare Your HVAC System for Spring

  1. Check your filters
  2. Get an air conditioning tune up
  3. Upgrade to HEPA filters
  4. Get a duct cleaning
  5. Get a dehumidifier
  6. Get UV lights


Our professional, highly trained HVAC Specialists can handle it all. Call (203) 338-0371 or fill out the form below if you have any questions or want to schedule an appointment.


Thank you! Your subscription has been confirmed. You'll hear from us soon.
Newsletter Sign Up
Get the latest info on new products and special promotions.