by High Performance HVAC | Technical Reference |
Ohms Law and HVAC - Ohms Law is used by HVAC Technicians, electricians, electronics technicians, engineers, and others who deal with electrical circuits every day. It is a necessary fundamental that anyone dealing with electricity or electronics should learn. Ohms law is used in many different applications to solve problems (troubleshooting electrical problems), for sizing wire and designing circuits, and for designing printed circuit boards (PCBs). Ohms law is a basic fundamental formula that helps electrical specialist solves problems. Ohms Law is necessary to learn if you are going to be an above-average technician in HVAC.
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by High Performance HVAC | Technical Reference |
Air Conditioning and Heating Sizing - It is not uncommon for HVAC estimators or HVAC contractors to use various rudimentary techniques, which are generally referred to as rules of thumb. Some will say on the low end you need 1 ton of cooling for every 500 square feet.
On the high end, you will need 1 ton of cooling for every 700 square feet. These rules of thumb will also generally take into account a basic heat gain calculation for the kitchen and the number of people who will occupy the structure. (more…)
by High Performance HVAC | Technical Reference |
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…)
by High Performance HVAC | Technical Reference |
Some things are very obvious
Home Inspector HVAC Training - Thank you!! I am training to become a home inspector, and the info contained on this site helps identify issues that require an HVAC professional to resolve. (more…)
by High Performance HVAC | Technical Reference |
Start Capacitors for HVAC Compressors - HVAC single-phase compressors always come hooked up to a run capacitor. This helps the compressor when it is running, however, very few HVAC compressors come with a start capacitor. Most HVAC technicians know HVAC compressors pull a lot of amps on startup. This large amperage draws on startup is referred to technically as locked rotor amps or inrush current. It can be as much as 40,000 watts or more of pure power to get an HVAC compressor started. (more…)
by High Performance HVAC | Technical Reference |
Basic Electric Circuits for HVAC - If you are new to electricity and want to learn you need to start with the fundamentals of electricity first. Included in the basics of electricity and the primary lesson in electricity is electrical safety. Electricity can be very dangerous and safety needs to be practiced. Electricity is invisible to the eye and can only be felt when touched. (more…)
by High Performance HVAC | Technical Reference |
Motor Controls for HVAC - Motor controls are necessary to start and stop air conditioning and heating motors automatically or manually. The most common manual motor control for air conditioning and heating is the thermostat. The thermostat starts and stops the blower motor on their home air conditioning and heating system. It is the Fan – Off – Auto switch on the air conditioning and heating thermostat. This switch when placed in the on position turns the blower motor on. It circulates air continuously until the user turns the thermostat fan switch to either the off position or the automatic position. (more…)
by High Performance HVAC | Technical Reference |
HVAC Definitions Terms & Acronyms | Heating Cooling - This is a comprehensive list of HVAC Definitions Terms & Acronyms. High Performance HVAC is certain there are more terms and acronyms. If you know of something we missed please email us. Thanks! (more…)
by High Performance HVAC | Technical Reference |
Liquid to Vapor Propane Evaporators
These evaporators serve a large complex where natural gas is unavailable. The complex needed fuel for boilers for heating and domestic hot water so these evaporators were installed too along with two very large LP tanks to handle the heating needs of the complex. As liquid propane (LP) has a specific weight of .504 (where water is 1) and propane vapor has a specific gravity of 1.5 (where the air is 1) making propane vapor 1.5 times heavier than air. (more…)
by High Performance HVAC | Technical Reference |
Grounding and Bonding Electrical Systems | NEC Code - National Electrical Code Article 250 is all about grounding and bonding as represented in this photo where electrical systems are grounded and bonded to the buildings steel structure.
There are many different rules in the NEC (National Electrical Code) pertaining to grounding and bonding because grounding and bonding are important for safety reasons. Electricity will take the path of least resistance so if there is a short in the system the grounding system will be the path for the electricity instead of the motor or load that experiences the short. (more…)
