This job is a three-story office building with an air handler on each floor with a refrigerant coil in each air handler. A 75-ton condensing unit serves the three 25-ton air coils. This is an old system that has still been doing a good job. The complaint is that the second floor unit is not holding the conditions that the thermostat is set for.
In steam systems that have not been maintained for three to five years, between 15 percent to 30 percent of the installed steam traps may have failed - thus allowing live steam to escape into the condensate return system. In systems with a regularly scheduled maintenance program, leaking traps should account for less than 5 percent of the trap population.
The day started with a call from the dispatcher who described a gas heat customer who had no heat. When Bob arrived, the first thing he noticed was that the furnace was cold. It had not been operating. At first, Bob thought that the thermostat was defective. Btu Buddy then arrived to clear up his confusion.
Your troubleshooting situation this time around relates to a walk-in refrigeration system in a busy restaurant that has experienced a compressor failure… specifically a mechanical failure. And it’s not the first time.
Many servicemen experience service calls where the compressor has both a low head pressure and a high suction pressure. There are three main reasons why a reciprocating compressor will simultaneously have a low head pressure and a high suction pressure.
Bob and Btu Buddy have gotten together for coffee to discuss the previous service call and some of the questions about electric heating that came up. Btu Buddy said that they would talk about them one at a time, and probably other questions would come up.
When you improve chiller efficiency, you can have better control of the chiller and the air conditioning in the building, and the chiller will also last longer. The recommendations here are for centrifugal chillers. Several different methods are suggested.
A call has come in from a new customer that the system in a small office building is not heating properly. Bob finds the building has an electric heat furnace and, when he removes the panel, he is amazed at how many wires and terminals there are and starts to become confused. Btu Buddy arrives to assist him.
Many larger compressors in the refrigeration and air conditioning field have forced-oiling systems. These compressors are usually over 5 hp. They contain an oil pump located at the end of the compressor’s crankshaft. The crankshaft is actually connected to the oil pump and supplies power, which turns the oil pump.
In this month’s troubleshooting situation we’re taking you to a modular classroom with a heating/cooling unit that employs resistance-type elements for the heating mode, and a direct expansion system for cooling. The complaint is that there is “very little cooling” being accomplished.
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