When multiple compressors are piped together with a common suction and discharge header - such as with the arrangement of a parallel rack configuration - oil return to each compressor is a major concern. Typical oil recirculation rates are dependent on three factors.

Bob has gone on a service call where the customer is complaining that her house is not getting up to temperature. The house was heated with a heat pump with three stages of auxiliary strip heat. Bob removed the panel to the strip heat and found one of the units was not pulling current.

This troubleshooting situation is a look ahead to the upcoming cooling season. Our customer has called to say that their heat pump “isn’t cooling at all,” and while the outdoor temperature is only in the mid 80’s, it’s quite uncomfortable in the house. You find that the underlying reason is that the compressor and outdoor fan motor aren’t operating.

The tough economy has led many contractors to hunker down, conserving resources and cutting expenses. Other contractors are taking the opposite approach, investing in their companies and expanding operations to include additional profit centers. While there are different ways an HVAC contractor can go, most look to plumbing or electrical as natural extensions.

It is the time of year when I get calls for heat pumps not cooling properly. With a little prodding, I usually hear that the past month’s electric bill was also high, even though it wasn’t that hot. These calls always raise one major red flag for me. One of my first questions is if the heat pump is properly elevated up off the pad.

Crockett Facilities Services Inc. (CFSI), a provider of building operations and maintenance, mechanical contracting, and HVAC services to government and commercial clients, was recently awarded a contract by the National Aeronautics and Space Administration (NASA).

The NEWS interviewed contractors around the country who are taking steps to handle unexpected weather and extreme conditions that may compromise safety. The Center for Disease Control and Prevention and the Federal Emergency Management Agency have provided safety tips for businesses and consumers who can be adversely affected by this year’s strange weather patterns.

The process of brazing ACR tubing is a common task for many refrigeration technicians. Although this is relatively simple, there are some system problems that can occur if some basic brazing procedures are not followed.

The poor economy has been hard on commercial businesses. In some cases, HVAC contractors still have service agreements with local malls and office buildings, but often, that work is being outsourced to national maintenance organizations. HVAC contractors have partnered with these organizations. Some sing their praises while others now turn and run.

A preventive maintenance program at a leading New England Ivy League university demonstrates how the push for more sustainable building management has led to a growing awareness of a chronic, widespread problem for HVAC motors: electrical bearing damage.