A leaking chiller forced an automotive manufacturing plant’s HVACR engineer to decide between a costly production shutdown or using a can of refrigeration system sealant to eliminate the leak. Deciding on the sealant quickly put a lid on the engine factory’s repair fees.
The dispatcher calls Bob about servicing an old oil furnace. The customer is old and is adamant that he doesn’t want a new furnace, so Bob does not try to get
him to upgrade to a new model. He tells the customer that he will see that he
gets the most out of the old furnace that he can.
Air conditioning system commissioning and startup is the process of inspecting a new air conditioning installation, and verifying that the new system is running properly and efficiently. This article describes the commissioning procedure.
Bob and Btu Buddy get together for lunch and talk about why high head pressure seems to drive up the power consumption of a compressor. Bob remarks that the problem “doesn’t seem to happen in the cooling season, only in the heating season. What is the difference and why is this happening?”
Dealing with a user’s complaint of a noisy motor can be a frustrating experience. After all, the perception of noise is extremely subjective (just ask the parents of teenagers). Not only does the range of human hearing differ considerably among people, but it also varies by specific frequency.
Bob is called to a new customer’s home with a 5-ton heat pump that is experiencing power bills that are considerably higher than the same months last year. Btu Buddy assists Bob in diagnosing the problem.
In this column, Jim Johnson of Technical Training Associates presents a specific HVACR equipment problem and invites readers to submit their diagnosis. From those who submit the correct answer by the deadline, there will be a prize drawing. Here is a furnace problem.
The dispatcher calls and tells Bob that yet another person is describing an unusual smell when the furnace runs for a long period of time. Bob talks to the homeowner, checks out the furnace, and finds that it is backdrafting slightly. With the help of Btu Buddy, he tracks down the draft problem.
The information provided here on assorted water heater
problems assumes that the water heater was properly installed and was operating
correctly before any problems developed. This is just a general guide to the
most common water heating problems.
Btu Buddy and Bob meet for lunch and Bob has a question about the last service call. The job involved replacing the single-wall flue pipe with double-wall pipe. “You said that we had some unfinished business about the service call yesterday, yet you said that the call was complete. What did you mean?”
In this column, Jim Johnson, director of training for Technical Training Associates, presents a specific HVACR equipment problem and invites readers to submit their diagnosis. From those who submit the correct answer by the stated deadline, there will be a prize drawing.
Bob goes on a call to a house where the residents smell fumes when the furnace is running. He examines the flue connector from the furnace to the chimney and discovers it’s rusted to the point of falling apart. With the assistance of Btu Buddy, he replaces the single-wall vent pipe with a double-wall vent.
A very common freezer repair trouble call is a frozen evaporator
coil. When you open the door to inspect the coil, look around for signs of
outside air migrating into the box.
Bob had changed a compressor and was just
about ready to charge the system when a problem arose. He pulled a vacuum down to 500 microns but noticed a rise in the vacuum gauge to 1,000 microns. There was a leak and Btu Buddy assisted him in finding it.
With this article, The NEWS is introducing a new online column called “Troubleshooting With Jim Johnson.” In this column, Jim Johnson, director of training for Technical Training Associates, will present a specific HVACR equipment problem and invite readers to submit their diagnosis.
The first Copeland Scroll® rolled off the production line in 1987, and the cooling industry was changed in a way that would benefit contractors and their customers in many, many ways. The prime benefits have been efficiency and product reliability.
Many features of the Scroll focus on preventing compressor failures, but the Scroll’s primary design also improves efficiency and reliability thanks to its classic, concentric compression scroll, in which one spiral-shaped part fits into another; the space between the two parts contains crescent-shaped gas pockets.
CLASSIC SCROLL OPERATION
In operation, one Scroll is fixed in place while the other orbits within the first. The refrigerant gas is drawn in by the movement and forced toward the center of the scroll through successively smaller pockets, thereby increasing the gas pressure until it reaches its maximum pressure. Then it’s released through a discharge port in the fixed scroll.
Copeland Scroll compressors are unique in the industry because they feature both axial and radial compliance in their design, whereas other scroll models utilize a mechanically fixed design and scroll tip seals.
Axial compliance refers to the ability of the scrolls to separate in the axial — or vertical — direction remaining in continuous contact around an axis, in all normal operating conditions, ensuring minimal leakage without the use of tip seals. Radial compliance refers to the ability of the scroll flanks to separate. These features of the Scroll design allow the compressor to be more tolerant of liquid refrigerant or debris than other technologies, making for a compressor that is extremely durable and reliable.
The combination of axial and radial compliance means that Scroll compressors actually “wear in” rather than wearing out. Continuous flank contact, maintained by centrifugal force, also minimizes gas leakage and maximizes efficiency of the compressor.
Next month: Tech Tips will begin examining the Scroll’s improved reliability through its oil control system.
For more information, click on the Emerson Climate Technologies logo above.
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