HVAC Control and Direct Digital Controls 2 - An HVAC technician who knows nothing about HVAC control systems would wonder how these HVAC control systems work. To understand HVAC controls, one must understand basic electricity and circuits.
The NEC and HVAC Chapter Two - Chapter Two of the National Electrical Code (NEC) covers Wiring and Protection and starts at Branch Circuits, Feeder circuits, GFCI requirements and protection. An HVAC installer may want to pay attention to branch circuit requirements. Article 220 in Chapter two of the NEC includes calculations for branch and feeder circuits including service calculations. (Table 220.3) (more…)
Find Tonnage on AHU | HVAC Equipment Nomenclature - How do I find out the tonnage on an AHU (Air Handling Unit)? The label/tag has faded all I have on file is the model number and the serial number, make.
Question Posted By Francisco the Building Engineer on May 3, 2011
Refer to the manufacturer’s website for their HVAC nomenclature of the model number and serial numbers and how those numbers correspond to the tonnage and other technical data. Or you can call your local dealer for the manufacturer and they will tell you. (more…)
Many people wonder what Building Automation Systems (BAS) can do. The primary use of BAS is commercial HVAC control systems and energy management system applications. Building Automation itself is an energy management system that saves management companies and building owners by efficiently controlling air conditioning and heating comfort and process systems.
Preventive Maintenance Air Handlers - These air handlers provide air conditioning for a zoned VAV system. The air handler is an integral part of an air conditioner system. The air handler contains a blower, air filters, some coils (DX or chilled water), hot water coils (not all air handlers have heating coils in them), and some controls. (more…)
Thermostat Wiring Colors Code Page Navigation
Always follow the thermostat manufacturer’s instructions whenever changing the thermostat. Always turn the power off at the air handler and the condenser and make sure there is no voltage at the transformer before proceeding.
For instructions on how to wire a thermostat, please see how to wire a thermostat page. Refer back to this page for thermostat wire colors.
Chilled Water Pipe Vibration Isolators - Vibration isolators protect the chilled water piping from receiving vibrations transmitted through the piping when the chillers are running. The vibrations can create problems not only for the chilled water piping but also for the building’s structure. The vibration isolators reduce or eliminate the vibrations that can be transmitted by the chillers. (more…)
Hot Water Unit Heater Protecting Mechanical Room - Unit heaters are used in various places to protect equipment and provide comfort to occupants. This hot water unit heater provides protection for a mechanical room where there is a large air handler and other associated equipment in the mechanical room. This system is controlled by DDC. A thermostat on the wall detects the temperature of the mechanical room. (more…)
Siemens Apogee DDC Controller
BAS DDC Learning | HVAC - HVAC Building Automation Systems (BAS) or Direct Digital Controls (DDC) is pretty much one and the same. Basically described BAS and DDC are combining air conditioning, heating, ventilation, lighting, electrical loads, security systems, and life and safety systems to a computer and complex algorithms for better control over the systems. (more…)
York Versus Carrier Air Conditioners - Every manufacturer has their own parts system and sometimes these parts are readily available aftermarket and sometimes the parts are proprietary and can only be purchased through the manufacturer of that equipment. Carrier is one of the HVAC manufacturers that has proprietary parts and sometimes you will pay a premium for those parts.
The manufacturer can hold the customer hostage especially when it comes to repairing the unit. Of course, York is one of the big HVAC manufacturers and they too have proprietary parts however the parts are usually more reasonable for purchase as far as cost is concerned so people would lean towards purchasing a York simply because the replacement parts are not sold at a premium where with SOME Carrier parts are sold at a premium and are not easily replaceable except through a Carrier dealer.
