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…)
DDC Automated Logic M-Stack - This Automated Logic M-Stack provides a control for multiple pieces of HVAC equipment and integrates network communication all in one single stack. This direct digital control system is integrated with pneumatic controls. DDC allows automated HVAC control processes to take place and adds higher efficiency to an HVAC system. (more…)
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…)
Thermostat Selection Guide - This article will help you select the right type of thermostat for the HVAC system you have installed. It offers a comparison matrix for you to choose the right thermostat replacement. Get it right the first time!!!
So you have made a choice to replace the thermostat in your home or business and you decided to do it yourself. Hopefully, you will follow the advice on this website and read the instructions before replacing the thermostat.
VAV Air Handlers are ideal for providing zones in a commercial building. Office space typically has several offices and open areas that need to be conditioned for the comfort of the people working in those areas or offices. By installing VAV boxes and zoning the ductwork from those VAV boxes these areas and offices can be kept comfortable using a VAV air handler system. More on how VAV boxes work. (more…)
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…)
HVAC Definitions - In air conditioning and heating the name HVAC is often used. HVAC stands for heating, ventilation, and air conditioning. Other acronyms are less used to describe air conditioning and heating applications is HVACR or heating, ventilation, air conditioning, and refrigeration and HACR or heating, air conditioning, and refrigeration. (more…)
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.
HVAC Damper Actuator for Economizer Free Cooling - This damper actuator controls a free cooling damper for an economizer. It is part of an economizer damper system which allows free outside air cooling when the outside air temperature and humidity are ideal. In the Fall and the Spring when the outside air temperatures are mild it is unnecessary to run the air conditioning system to cool the building if the system is set up for free cooling. (more…)
DX CRAC Unit Condensers | Critical Facility HVAC - Most data centers do not utilize HVAC DX (Direct Expansion) CRAC units or air conditioning but instead use chilled water systems to provide cooling for the data center. In smaller buildings such as remote telecom buildings, DX air conditioning systems are used to keep the equipment cool and operating efficiently. (more…)
