by High Performance HVAC | Air Conditioning |
Air Conditioner Sequence of Operation - When a technician is troubleshooting an air conditioner problem it is important that the technician understands the air conditioner sequence of operation for that equipment. When there is a problem with the equipment, including air conditioners, the technician will know the problem if the equipment or air conditioner does not follow the sequence of operation. Sometimes it is that easy, and other times it is not that easy when troubleshooting any HVAC equipment. However, it is important to understand the sequence of operation for air conditioning so the technician can troubleshoot the problem. (more…)
by High Performance HVAC | Commercial HVAC |
Actuators for Chilled Water Valve - These chilled water actuators control the flow rate for a chilled water system in a data center. There are various sequences of operations for chilled water systems and the sequence of operations is usually always different from one chiller plant to another chiller plant. (more…)
by High Performance HVAC | Air Handlers |
Air Handler Water Coil Freeze Stat - The HVAC Air Handler Freeze Stat is a low-temperature limit control and it is used mainly in commercial systems in the ductwork on economizers or in air handlers just before any coil especially water coils. It is a safety and protection control to prevent extremely cold air from reaching the hot water or chilled water coils inside the air handler where the air enters from the economizer.
Under ideal control setup if the freeze stat trips the economizer dampers close and the blower fan stops. This prevents coils from freezing. A frozen coil can bust open and will need to be replaced if it freezes. This is the purpose of the freeze stat in HVAC air handler applications which utilize economizers for free cooling and other purposes.
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by High Performance HVAC | Heat Pumps |
Heat Pump Sequence of Operation - Every electrical-mechanical piece of equipment has a sequence of operation. While some manufacturers of heat pumps vary slightly with their heat pump sequence of operation the overall sequence of operation for a heat pump is the same for most manufacturers. So unless you have a special type of heat pump (they are out there – the Acadia heat pump is designed for extreme cold weather temperatures up North like Canada) the sequence of operation for your heating equipment should be very similar to what is described here. This is the basic operation of a heat pump like you will find in conventional heat pumps.
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by High Performance HVAC | Air Handlers |
Air Handler Return Dampers | HVAC Components - These return air dampers serve a large air handler on a rooftop. This return air damper ends up in a mixing box inside the air handler where the return air from the building mixes with the outside air from the economizer. (more…)
by High Performance HVAC | Heat Pumps |
Heating with Heat Pumps | HVAC Systems - There are some people who say that heat pump heat is not as warm as other types of heat. Heating sources such as a hot water boiler or even a steam boiler. Even the forced air gas furnace gets more credit for providing better heat than the heat pump. Heat pumps are extremely popular in the southern states where the heating season is short. Additionally, where the temperature rarely dips below 35 degrees F. (more…)
by High Performance HVAC | Gas Furnaces |
Furnace with Hot Surface Ignition
Hot Surface Ignitor - Whenever we talk about electronic ignition systems in gas furnace ignition systems we must first look at the key components which make these systems work and understand how they work. Hot surface ignitor systems work in various ways.
This all depends on what the electronic ignition manufacturer and design engineer determined in the design. Furthermore, some are direct main burner ignition while others light a pilot, and the pilot lights the main burners.
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by High Performance HVAC | Commercial HVAC |
Variable Air Volume Systems - Variable Air Volume (VAV) systems are the best way to zone especially in large buildings. A VAV system with the proper controls and setup will help the building owner realize large savings in energy usage. There are many VAV systems out there set up in different ways. The most common set-up (for DDC) is, of course, usually the cheapest to install.
They have an air handler (DX or Chilled Water) which supplies the VAV Boxes with fixed pressure and temperature of the conditioned air. The VAV Boxes have electric reheat which will heat the air if that particular zone calls for heat (it is not uncommon to also find VAV boxes that have hot water reheat although this usually costs more to install but can save in energy costs). More on how VAV boxes work.
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by High Performance HVAC | Heat Pumps |
Heat Pump Problems | HVAC Heating & Cooling - Heat Pumps are very popular especially in the South where air source heat pumps are mostly favored over straight air conditioners with a gas furnace for heating. 
With a heat pump, one system can provide heating and cooling. Some people rely on a geothermal heat pump system or a water source heat pump. A geothermal heat pump extracts heat from the ground instead of the air like an air source heat pump works. (more…)
by High Performance HVAC | Thermostats |
Heat Pump Thermostats - To the average person a heat pump thermostat can be a very complicated thermostat compared to the typical thermostat which serves an air conditioning system with gas, electric, or an oil furnace. Of course, the heat pump thermostat typically has more wire terminations than the regular thermostat.
It has more switches to control emergency heat, and some even have lights, which will indicate that the auxiliary heat or emergency heat is functioning. Most heat pump thermostats are two-stage thermostats for the heating mode and a single stage for the cooling mode.
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