Enthalpy is defined as the amount of internal energy within a system combined with the product of its pressure and volume. When dealing with the term in the HVAC industry, we usually assume that the process is at a constant pressure and, as such, the change in enthalpy is equal to the heat absorbed or released. At its core, the main function of an HVAC system is to transfer heat, which is a form of energy. The first law of thermodynamics, the Law of Conservation of Energy, tells us that energy can neither be created nor destroyed; energy can only be transferred or changed from one form to another. From that, we can infer that the only way to cool a space down is to remove the heat energy and transfer it somewhere else, typically outdoors. This is generally accomplished by absorbing heat from an airstream and then distributing this cool air to the area we wish to control; it helps to think of conditioned air like a sponge with the capacity to ‘soak up’ heat. The air, now laden with unwanted heat, is routed back via a Return Air pathway to start the process over again. The newly absorbed heat is ‘wrung out’ and expelled, and the cool air is distributed again in a constant cycle. This ‘wringing out’ process is mainly accomplished by mechanical cooling, such as a compressor, or free cooling provided by an air-side economizer.Continue reading Enthalpy as it relates to free cooling in HVAC
The world of HVAC changes every day. There are constantly new developments in equipment and how to reach pique efficiency when cooling and heating large-scale facilities. Check out the trade show and conference calendar below to find an upcoming event near you to stay up with the latest trends in 2019.
After investing nearly two years and $2 million in the purchase and renovation of its new headquarters, Computrols hosted its grand opening event Friday, April 20th. The event was well attended by members of the media, elected officials, local support organizations, and Computrols’ partners, customers, and employees. Continue reading Computrols Grand Opening Recap
As a part of our services, Computrols offers 24/7 phone support to all of our customers. If you have ever taken advantage of this offering, you have likely spoken to our Technical Support Manager, George Hingle. George has been employed by Computrols for over 15 years and is one of our most knowledgeable team members when it comes to troubleshooting in CBAS. As a means building on our already robust FAQ page, George has agreed to share some common challenges he sees in our newsletter each month. Continue reading George’s CBAS Tips, March 2018
Optimal Start/Stop is used to anticipate the heating or cooling needs of a space by starting equipment early enough to reach setpoint just at the beginning of scheduled occupancy. The Optimal Start/Stop function in CBAS does this by calculating the difference between the actual temperature and the occupied temperature setpoint. Based on a heating or cooling slope, the unit is started early enough to bring the space temperature to the desired level. Continue reading What is Optimal Start/Stop and How Does it Work?
The Lyric Centre, located at 440 Louisiana Street in downtown Houston, recently became one of Computrols newest customers. The building is 26 stories tall and provides approximately 385,000 square feet of commercial office space.
The Computrols Houston branch kicked off the project in October of 2017, integrating to the existing Johnson Controls system. In addition to interfacing with the existing JCI, DDC equipment, a core Computrols infrastructure is being installed. This infrastructure consists of a new headend computer, software, and lifetime-warranty controllers to replace the existing NAEs. These new DDC controllers communicate to the existing JCI equipment via N2 and BACnet protocols, enabling the building staff to monitor and control the existing JCI equipment. Computrols will also be providing additional lifetime-warranty controllers for future pneumatic to DDC floor conversions. Continue reading HVAC Controls Project: Lyric Centre – Houston, TX
In one of our recent articles, we discussed static pressure control and variable air volume (VAV) systems. We mentioned that by modulating the leaving air temp from an air handling unit (AHU) we can promote energy efficiency while also having an effect on static pressure. This time, we’ll look into how AHU supply temp sets the stage for efficient VAV operations.
Typically, VAVs are equipped with a means of reheating the supply air provided by the corresponding AHU. Continue reading AHU Supply Temp Sets the Stage
Static pressure is a key ingredient in a successful Variable Air Volume (VAV) system. It ensures that air flow will be available to enable the VAVs in a system to achieve their designed Cubic Feet per Minute (CFM) at maximum demand. Simply put, the push of the air must be greater than the resistance to the flow or no air will circulate through the ducts. Typically the setpoint for static pressure is determined through the course of the testing, adjusting, and balancing (TAB) at the end of a job. Continue reading Static Pressure Control and VAV Operation
Energy and water conservation deliver a wide range of advantages, including cost-related benefits, ancillary savings, infrastructure improvements, reduced pollutant emissions, improved energy security, and, in some cases, increased productivity. Continue reading Energy Efficiency Measures for Winter
Computrols is further expanding its footprint in Tampa, FL by having been awarded the opportunity to provide a complete pneumatic to DDC controls retrofit at One Tampa City Center. Over the next several months, Computrols will be working to install a number of its controllers to improve HVAC control and energy efficiency in the 750,000 square foot Class A office tower.
Computrols will be retrofitting the Tampa City Center’s current pneumatic system with its state of the art DDC building automation system. This new system provides technology that will allow for a new level of temperature control to enhance tenant comfort while reducing energy consumption.
The upgrade is scheduled for completion in September of 2016. The updated components will include: Continue reading Computrols Building Automation Project: Tampa City Center