Active in the HVACR industry since the 1950s, Bill Johnson graduated in gas fuel technology and refrigeration from the Southern Technical Institute, a branch of Georgia Tech (now known as Southern Polytechnic Institute). He taught HVAC classes at Coosa Valley Vocational & Technical Institute for four years. He moved on to become service manager for Layne Trane, Charlotte, N.C. He taught for 15 years at Central Piedmont Community College, part of this time as program director. He had his own business for five years doing installation and service work. Now retired, he is the author of Practical Heating Technology and Practical Cooling Technology, and continues as a co-author of Refrigeration & Air Conditioning Technology, seventh edition, all published by Delmar Cengage Learning. For more information, he can be reached at 704-968-0000 or firstname.lastname@example.org.
Btu Buddy Notebook is a collection of more than 50 service call scenarios in book form covering both cooling season and heating season troubleshooting. For more information and to purchase the book, visit the HVACR Industry Store.
Bob and Tim have had a big day at work — it’s 3:30 in the afternoon, and they are done for the day. They’re having coffee at a local restaurant, talking about their careers when Tim asked a question, “What is a ton of refrigeration, and why is it called a ton?”
Bob and Tim were on their way to a no heating call. When they arrived, they looked at the house and saw that it had a package unit. They talked to the housewife and she told them that the unit stopped running sometime in the middle of the night last night.
Bob and Tim were checking a customer's air conditioner and initially thought the unit must be out of refrigerant or very low on refrigerant. But after adding some refrigerant, the suction pressure did not rise at all. Bob then determined they should look for restrictions in the liquid line or the suction line.
Bob and Tim were at a customer’s house doing a seasonal checkup on a condensing gas furnace. This was routine service carried out every year on this customer’s equipment per a service agreement. But when they tried to operate the furnace, the burner would not light.
A customer was explaining what was going on with his air conditioning system. His old system had stopped working and he was told that it needed to be replaced. Money was tight and a cousin had a system removed from a rental property. So they replaced the original 3-ton package unit with a 4-ton package unit.
Bob and Tim had just arrived at a service call, the first one for the day. The complaint was that the homeowner’s air conditioning had stopped sometime in the night and the residence was hot. After their initial checks, they suspected a low charge.
Bob and Tim were on their last service call for the day. It was an apartment house with a heat pump and the weather was warm during the day and cool at night. The tenant had just moved into this apartment and was trying to get the air conditioning to operate to her satisfaction and she said it was too breezy.
Bob and Tim were at the house of a customer who said that her air conditioning unit did not cool well in the hot weather three days ago. She said the unit actually froze up and had ice on the outdoor portion of the unit on the big line. She shut the unit off and called for service.
Bob and Tim had just arrived at the house of a new customer who explained that the air conditioning system was not working. The homeowner said that they had just had a warm day and the air conditioning system did not come on when they tried to cool the house down yesterday.
Bob and Tim had just finished a routine service call on a house with a gas furnace for the heating system. They were talking to the housewife when she asked: “Our house is very dry in the winter time, and the humidity must be very low. How can we put a system in this house to keep the whole house at a higher humidity level?”