VAV Box Types Fan Powered and Shut Off

VAV Box Types Fan Powered and Shut Off VAV Boxes - When attempting to name the different types of VAV boxes we find there are different names given to VAV boxes by different people and we find that no one is on the same page when VAV boxes are definitively defined.

We have fan-powered VAV and non-fan-powered VAV’s and we have series and parallel VAV’s and we have VAV boxes with a hot deck and a cold deck that mixes and one of the last projects I worked on some of the VAV’s were referred to as shut-off vavs. Variable Air Volume Boxes (VAV Boxes) regulates airflow into zones using a primary air source from a VAV air handler.

VAV Box Types Fan Powered and Shut Off

  • Cool only single ducted series
  • Fan-powered single duct series with reheat
  • Fan-powered single ducted parallel with reheat - uses plenum air before using reheat for energy efficiency

Aside from the control aspect of VAV boxes, pneumatic, electric, electronic, or DDC, there are many different variations to VAV Boxes and we will attempt to define each type of VAV including offering a diagram of each type and matching it with a specific application. VAV boxes are simply an assembly of a damper, damper controls, and sometimes reheat such as electric heat strips or a hot water coil. VAV boxes get their primary air source from a central VAV air handler and then distribute air throughout a specific zone the VAV box controls.

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Data Center Commissioning Basics | HVAC Functional Testing

Data Center Commissioning BasicsData Center Commissioning - A load bank that gives a heat load for testing the cooling system in a data center. The load banks are also used to give the electrical system a load for testing the data centers electrical equipment and redundancy.

PDU’s or Power Distribution Units, switchgear, automatic transfer switches, static transfer switches, UPS, or universal power supplies along with banks of batteries, are all tested in conjunction with the load banks. (more…)

Portable Load Bank for UPS Testing | Commissioning

Portable Load Bank for UPS TestingPortable Load Bank for UPS Testing | Commissioning - This is a portable load bank used for testing small UPS (Universal Power Supply) systems and for other electrical loads. New UPS systems are tested to ensure they operate properly and can hold the designed load whenever a power failure occurs.

It is a way to test the UPS system without hooking up an actual load to the system with the actual load being the computer systems the UPS will power in the event of a power failure.

This testing ensures the UPS equipment will functionally operate after the intended load is hooked up to the UPS system. Included in the test is a time factor on how long the batteries will power the load without utility or a backup generator. On specific construction projects, whether it is new construction or retrofit projects, data centers and telecom facilities go through the commissioning process.

The commissioning process tests all electrical and mechanical devices under normal operation and under full load conditions. Other scenarios are tested such as equipment failure, infrastructure failures such as piping or utility loss, and plans implemented for operational procedures in case these scenarios occur.  (more…)

Cooling Tower Fan | Commercial HVAC

Cooling Tower FanThis is an HVAC chilled water system cooling tower fan for a large chilled water system. Four large cooling towers for two chiller plants in a data center. Data center cooling systems generally are redundant not only for emergency situations but also for maintenance. The cooling tower fan typically has vibration switches installed in the fan assembly to shut the fan off in the event of too much vibration. (more…)

Cooling Tower Evaporation Cools Water | HVAC Technical

Cooling Tower Evaporation Cools WaterCooling Tower Evaporation Cools Water | HVAC Technical - Cooling towers use the process of evaporation to cool or removes heat from the condenser water that was transferred to the water in the chiller condenser barrel. The heat is absorbed in the load in this case in a data center on a data center floor. The servers and electrical equipment produce a massive amount of sensible heat.

The heat is absorbed by computer room air conditioners or computer room air handlers. These systems, computer room air handlers, and air conditioners have chilled water coils. The chilled water originates at the chiller into the primary loop. The water circulates through the primary loop and makes its way into the secondary loops. (more…)

Data Center Perforated Tiles for Cooling Servers

Data Center Perforated Tiles for Cooling ServersData Center Perforated Tiles for Cooling Servers - There is a lot to consider with perforated tiles in data centers and depending on who you talk to you will get different answers. The server floor in a data center is typically built on a raised floor with cold air being pumped under the floor by large CRAH (Computer Room Air Handlers) or CRAC units (Computer Room Air Conditioners). (more…)

Day Tank for a Diesel Generator | Critical Facilities

Day Tank for a Diesel GeneratorDay Tank for a Diesel Generator | Critical Facilities - This is a photo of a generator day tank for a diesel generator. The tank has floats inside that keep the fuel level automatically topped off in the tank so when the generator starts there is a fuel supply ready to go. As the generator consumes fuel the pump activates and resupplies the tank to keep the generator fueled and running. (more…)

Dust Smoke Filter Banks | HVAC Ventilation Systems

Dust Smoke Filter BanksDust Smoke Filter Banks | Indoor Air Quality

Dust Smoke Filter Banks - These filter banks filter the exhaust air from a welding lab where lots of smoke, fumes and related dust ends up going through these smoke filter banks. Specialized filtering systems are commonly used in industrial areas where fumes, smoke, and dust can be hazardous to the health of people working there. (more…)