Premise
An HVAC all Season Air Rotation Circulation System
An effective air rotation system is the key to efficient, comfortable and cost-effective air conditioning, heating and ventilation. The AirBoss “SmartAir” Design technical details presented in the accompanying AirBoss “SmartAir” Design Engineering Analysis, White Paper, makes it possible for HVAC designers to measurably reduce air conditioning equipment required to cool facilities to within 2° F of thermostat set point. The AirBoss Design will eliminate floor to ceiling air temperature stratification and maintain equilibrium (without stratification) when the AirBoss system is operating 24/7.
The AirBoss Smart Design is specific to high ceiling (25 to 40 feet) warehouse and distribution facilities (with or without critical inventory requirements, including those that have strict FDA requirements) that are without interior partitions (interior walls that restrict air flow).
The AirBoss design utilizes AirBoss air handler units * that produce high cubic feet per minute (cfm) per unit of air flow and provide an adjustable method for controlling the direction and volume of air flow.
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*Air Handler Unit
AirBoss ceiling hung dual fan system that produces 33,000 cfm with a forward air discharge of approx. 300 lineal feet and left and right air discharge of approximately 150 lineal feet. The units have adjustable louvers and turning vanes that allow for fine tuning of air discharge direction. Weight 1,700lbs – width 102″, length 115″, height 49″. These units are typically located at the perimeter of a building along the first column line. This facilitates erection and avoids point design loads
Objective
The objective of the “AirBoss Smart Design” is to improve air circulation and eliminate temperature stratification which will reduce utility consumption by 20 to 40%. This improvement will positively impact facility cost and environmental objectives, including construction equipment and labor requirements, utility (gas and electric), maintenance, end of life equipment replacement and governmental and corporate sustainability objectives. Globally, AirBoss “SmartAir” method design positively impacts power grid balancing and environmental issues including green-house gases and natural resource depletion. Warehouses and distribution centers are a major part of the American commercial and industrial business and governmental complex. AirBoss system designs clearly present a proven cost-effective opportunity for business and government to reduce capital and operating cost and have a major positive impact on the environment when compared to other HVAC design approaches. A 20 to 40% equipment reduction (day one construction cost impact) and a 20 to 40% downstream, year over year utility reduction in warehouse and distribution center facility is powerful and important.
An additional critical objective is to achieve a warm weather ventilation design that dramatically improves comfort levels and employee productivity.
The fundamental concept of the AirBoss Smart Design is that engineers are able to manage internal facility air flow in such a way as to maintain a uniform temperature throughout, floor to ceiling, by utilizing AirBoss ER-242 air flow units that are designed to run full time 24/7 (no seasonal/weekend/AirBoss system night set-back). AirBoss units operate with ¾ hp fan motors that minimize utility consumption. Roof top package units or (direct fired recirculation 80/20 heating units) fan motors typically utilize large hp motors and even if they are run full time will not achieve the effectiveness of an AirBoss design from a cost or people comfort perspective. Typically, facility operators do not run RTU fan motors full time because it is simply not an effective air circulation solution, nor is it cost affective.
AirBoss “SmartAir” Air Conditioning and Heating Operating Concept Compared to Conventional Designs
Conventional Cooling Design
Typically, interior temperature is managed by a system of thermostats, each associated with a roof top package unit. When the temperature near a thermostat varies by +/- 2° F, the associated roof top package unit begins to operate. HVAC units draw air from the interior near the ceiling, pass it over cold coils and return it to the interior, about 20° F cooler. For example, assume a ‘hot’ day and an inside set temperature of 75° F. The air that is near the roof is about 10° to 15° F warmer at the ceiling than at the thermostat. That being the case, the air that enters the HVAC system, with returns at the ceiling, is 10° to 15° warmer because of the differential between the floor and the ceiling temperatures. All conventional design systems with 4-way diffusers for air circulation create a condition, referred to as ‘heat stratification’ (layers of air temperature, cooler at the bottom and warmer at the top)
AirBoss “SmartAir” Cooling Design
AirBoss systems prevent stratification because the air flow that is produced will maintain a uniform floor to ceiling equilibrium. When equilibrium is achieved, an HVAC system does not require as many system units or tons to maintain the thermostat set point temperature. The accompanying “AirBoss Smart Design an Engineering Analysis”, Technical White Paper, demonstrates how this result is achieved when the temperature is +/- 2° F throughout a facility. It is more efficient to cool air that is 2° F from thermostat set point, vs air that is 5° to 20° F warmer than the thermostat set point. AirBoss system design engineers calculate the most efficient number of facility air turns per hour to maximize the most efficient return air temperature over the coils. More air turns result in lower return air temperature. This calculation will determine the number and size of AirBoss air distribution units. This process will maximize the AirBoss system efficiency and will allow for a substantial reduction in HVAC tons by 22%+ for this element of the Smart Design and at the same time improve interior comfort for occupants, due to continuous air circulation.
AirBoss “SmartAir” Heating Design
The AirBoss heating solution offers significant efficiencies and cost-effective benefits. AirBoss benefits from that continuous dynamic air flow much the same way during all seasons. With its constant interior air circulation, in the heating season, an AirBoss system utilizes all internal heat loads which will reduce the number of gas or electric heaters needed for a design. A big advantage of AirBoss is the need to continuously run big hp RTU fans or supplemental ceiling fan systems is eliminated.
AirBoss “SmartAir” Heating and Warm Weather Ventilation System Operating Concept Compared to Conventional Design Approaches
Heating and cooling are proven solutions for employee comfort and critical inventory concerns.
INTRODUCING
AirBoss “SmartAir” ventilation designs make it possible for heat only installations to provide employee comfort during warm and hot weather conditions.
OPERATIONS
When the outside temperature is cooler than the interior temperature of the facility, typically over-night, with the AirBoss units on, set the outside air dampers open with fans on and fully open the wall louvers. This process will bring in the cooler night-air into the facility. The ER-242-800 AirBoss units will distribute and mix this air throughout the facility, cooling down the interior, (walls, ceiling, floor, racks, inventory and equipment).
Close the outside air dampers when the inside temperature equals the outside, typically early morning. This action traps cooler conditions in the facility and stops the intrusion of warmer outside air. The AirBoss units run 24/7, circulating the cooler air. The AirBoss units also provide circulation to eliminate warm spots within and to provide direct air circulation around the occupants. This displaces the need for interior fans. When the air temperature inside the facility equals the temperature outside, the cycle stars over by reopening the dampers.
With AirBoss “SmartAir” Design
Engineers are able to treat the entirety of a facility interior as a universe to be wholly managed. The AirBoss air flow throughout the interior space is dynamic, equating to fluid dynamics, i.e., a river of air throughout the interior, constantly and completely mixing which will maintain a consistent temperature equilibrium. If cool air is introduced from roof top units when there is a cooling requirement, the cool air (approx. 20° cooler than the ambient air temperature) will be, within mere minutes, mixed throughout the interior. If warm air is introduced from the heating unit when there is a heating requirement, the warm air (approx. 20° warmer than the ambient air temperature) will be, within mere minutes, mixed throughout the interior. AirBoss Smart Design air flow efficiency will not require additional tons for distribution, saving 10 to 30% for this element of the design.
With AirBoss “SmartAir” Design
Engineers are able to treat the entirety of a facility interior as a universe to be wholly managed. The AirBoss air flow throughout the interior space is dynamic, equating to fluid dynamics, i.e. a river of air throughout the interior, constantly and completely mixing which will maintain a consistent temperature equilibrium. If cool air is introduced from roof top unit when there is a cooling requirement, the cool air (approx. 20° cooler than the ambient air temperature) will be, within mere minutes, mixed throughout the interior. If warm air is introduced from the heating unit when there is a heating requirement, the warm air (approx. 20° warmer than the ambient air temperature) will be, within mere minutes, mixed throughout the interior. AirBoss Smart Design air flow efficiency will not require additional tons for distribution, saving 10 to 30% for this element of the design.
Summary
AirBoss, ER 242 air rotation units work in concert with each other, creating a dynamic air flow, i.e., “a river of air”. Other HVAC designs more or less space the unit according to the manufacturer determined air throw of the unit, each with its own supply diffuser and return duct, which acts as a loop or column of air since return ducts are generally located very close to each other. This strategy frequently results in an over design compared to an AirBoss design. Further, conventional designs frequently result in hot or cold spots due to areas that are not adequately covered by air flow or by occasional equipment breakdowns, which is not the case with AirBoss designs due to the dynamic air flow which is inherent to the AirBoss Smart Design. AirBoss HVAC system design engineers utilize the ASHRAE design programs to determine the design loads and the number of AC tons for a conventional design. From this calculation designers can make a +/- 22% tonnage reduction. AirBoss system designs do not suffer from coverage issues because of the dynamic air flow that is generated, therefore additional tons are not required to achieve 100% coverage. Typically, this element of the design will avoid tonnage adds that can be as much as 20%. The design layout is academic because the roof top package unit and the air distribution unit can be easily located along the perimeter of the facility. With each unit’s louvers and turning vanes adjustments, and with the discharges of 300 lineal feet forward and 150 feet laterally (left and right) the layout solution becomes an easily solved physics air flow dynamics problem for the HVAC design engineer.