O'Brien Chamber Services

O'Brien Chamber Services is dedicated to providing the best work possible. OCS will meet or beat factory service. Response time is the fastest in the industry.
OCS specializes in calibration, repair, maintenance and upgrading environmental chambers of the Maryland, Delaware, and south-eastern Pennsylvania area. OCS can also setup your new equipment and train you on programming, use, and maintenance. OCS services brands such as: Cincinnati Sub-Zero (CSZ), TestEquity, Thermotron, Russells, Sun Electronic Systems, and Espec.


OCS can calibrate your programmable controllers, chart recorders, high and low limit controllers, and humidity sensors. Calibrations are traceable to NIST. All calibrations are stored in a computer database and can be recalled at any time.


OCS repairs cascade refrigeration systems, programmable controllers, humidity and altitude systems


OCS will keep your chambers in peak condition with a 50 point maintenance check. Tuning of control parameters for optimal performance and control. Increase run time between failure by taking care of small problems before they become large problems.

O'Brien Chamber Services was formed by Pat O'Brien. Pat has worked in the HVACR field since 1986. He was factory trained by Thermotron and was a field service engineer there for over 14 years. During his time at Thermotron he covered Maryland, Washington D.C., Virginia, Delaware and southern Pennsylvania. Pat has also been trained by Cincinnati Sub-Zero.