The History of Construction Safety - Anyone working in construction nowadays knows that there are mandatory safety standards in place to ensure the safety of workers.
Using heavy machinery, working at height or in enclosed spaces, or using dangerous chemicals all have their own set of safety procedures, and ignoring or flaunting these could lead to instant dismissal, or worse, injury or even death. This was however not always the case. (more…)
Owners Specifications and Submittals Commissioning - Attention to detail is a prerequisite for commissioning. This is especially true when looking through the project specs and finding the owner’s requirements for the project and then matching the owner requirement specs to what is provided by the contractor and then documenting everything as the commissioning specifications require.
This requires reading the specifications and matching everything up with the submittals for the project. Sometimes this is a monstrous task especially for larger projects with various types of infrastructure. (more…)
How Water Unit Heater in a mechanical room
Unit Heater Sequence of Operation – Mechanical rooms have very important equipment that needs to be protected. Often mechanical rooms are not conditioned and subject to outside temperatures and freezing conditions that can freeze piping inside the mechanical. For that reason, mechanical rooms often have unit heaters located there to protect piping and other things that cannot be frozen or subject to freezing conditions. The components and sequence of operation are fairly simple. The main components in a hot water unit heater include a fan, a valve, and of course the piping and coils along with the cabinet. Unit heater sequence of operation can also rely on an automatic control system but it can also be stand-alone. (more…)
Disconnect and Electric Motor Starter is used for turning the power off and on the electric motor used in HVAC applications. It also has overloads built into the starter so if one of the windings begins to pull too many amps the overloads open the circuit and the motor stops operating.
Motor starters can be used for single-phase and 3-phase motors and offer a manual way to turn the motor off or disconnect the electricity to the motor to prevent it from starting for maintenance or repair of the motor or peripheral systems. (more…)
Chiller Evaporator Barrel
Chiller Barrel Evaporator – A chiller evaporator barrel exchanges heat between one refrigerant and another. Usually, the primary refrigerant is R-22, R-134A, or some other blend or alternative HFC. The secondary refrigerant is water. This water is circulated throughout the building where it passes through piping and coils. This is generally in most cases a forced air coil where the heat is removed from the air by a heat exchange process with the water and the coil. The cooler air is then forced through ductwork and into the space to be conditioned. (more…)
Boiler Commissioning Functional Testing - Commissioning (Cx) any type of HVAC equipment is many different procedures from the beginning of the commissioning process to the end of the process. One of the most important procedures during the Cx process is functional testing. Functional testing always precedes the final testing where a test of all the combined equipment is done in an integrated systems testing. Once successful testing is completed and all discrepancies corrected a final commissioning report is generated including all the test data and information collected during the entire process of testing and commissioning.
This is simply a basic set of tests to be performed for boiler functional testing. Each system is different and will require a different tailored test based on equipment submittals, control programs, and design documents. The pre-functional checklist should be complete before engaging in this test.
Steam to Hot Water Generator HVAC Heating - There are some facilities including campus-like complexes that use a centralized steam plant as steam to hot water generator. The steam is generated from a large boiler and piped to various buildings around the campus or whatever facility is used. (more…)
How VAV Boxes Work? A Variable Air Volume box is typically installed in HVAC systems in commercial buildings and provides heating and cooling for occupants.
There are different types of Variable Air Volume boxes but how a Variable Air Volume box works is fundamentally the same from one Variable Air Volume box type to another.
Essentially a Variable Air Volume system allows an HVAC systems design engineer a way to zone large areas in workspaces such as office buildings and other places where there are large spaces that need heating and cooling or simply just cooling in rare cases.
Furthermore, the concept is simple but making it energy efficient and keeping everyone comfortable has taken some time from the inception of the Variable Air Volume box.
Variable Air Volume Box with Hot Water Reheat – The variable air volume box or VAV box is a commercial solution to adding multiple zones to large buildings. VAV boxes offer zoning solutions so that separate zoning demands or temperature selections can be maintained in different areas of the building.
If the president of the company wants the temperature in their office to be 70 degrees Fahrenheit but the vice president wants their office to be 74 degrees Fahrenheit then it is possible with the VAV zoning system as long as their VAV boxes are on different zones. (more…)
Glycol is like antifreeze and is used in chilled water piping loops to prevent freezing. Everyone knows when the pipes freeze they also break and start leaking. Having antifreeze in a chilled water loop is important to prevent freezing. (more…)