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Optimizing Your Heating, Ventilating and Air Conditioning Systems Optimizing Your Heating, Ventilating and Air Conditioning Systems Many modern buildings are designed with a forced-air heating, ventilating and air conditioning (HVAC) systems. While different types of designs may be found, the HVAC system has two critical functions: Hartford Steam Boiler One State Street − Control temperature and humidity for occupant comfort P.O. Box 5024 − Control indoor air quality for a healthy environment Hartford, CT 06102-5024 Tel.: (800) 472-1866 www.hsb.com One type of modern HVAC system achieves this by delivering a variable air volume (VAV) to a space. A VAV system provides many separate units, usually hung above the ceiling, to controls the various space conditions in defined zones of the building. Each zone has its own control sensor mounted in the individual space being controlled. This helps control energy costs by allowing the users to customize the space condition depending on the hours or use. In some systems this can be done for every room in the building. Most modern HVAC systems have a distributed control system that is accessible through the internet for setpoint adjustments or for remote monitoring. Many older systems still use room-unit ventilators. These are units that are installed against an outside wall of the room and are able to pull in fresh ventilation air through a small duct installed through the outside wall of each room. The heating function controls the space temperature in the winter but also preheats the cold outside ventilation air in the cold days of winter. Most of these systems are “heating only” units, but still provide uncomfortably warm, but ventilated rooms, during the warmer seasons. Many older control systems use pneumatic controls. A pneumatic control system uses air pressure signals rather than electrical signals to relay control messages from the rooms to the HVAC equipment. Pneumatic control systems require a noisy air compressor usually in the equipment room. Other larger area spaces are designed with constant air volume HVAC systems. Limited control capabilities contribute to energy waste. This occurs when large horsepower motors run while rooms are unoccupied. Any HVAC system that operates when it is not needed wastes energy. Hartford Steam Boiler Page 2/4 Optimizing Your Heating, Ventilating and Air Conditioning Systems While heating and cooling are ductboard to fall off allowing the to overflow and damage ceiling or seasonal, the ventilation systems seams to discharge air out of the floor tiles. Keeping condensate need to function whenever the ducts. Good integrity of the drains open and clean will reduce the building is occupied. Enforceable insulation and vapor barrier are chance for unhealthy microbiological building and mechanical codes especially important for ducts growth in the dark, damp air specify the ventilation options supplying cold air. Cold air ducts handling units. available for HVAC systems operating in an unconditioned air designers. Ventilation systems, like space will sweat and condense water Inspect for aging or deteriorated all HVAC systems, require frequent out of the hot muggy air. This coils in units and replace if maintenance to keep the system moisture can cause mold problems necessary. Rusting coil frames and working efficiently and effectively. in concealed locations above false flaking aluminum fins on the coils Failing to keep ventilation systems ceilings. will be hard to keep clean due to the maintained and controlled properly corroded surfaces. Steel that has lost has the potential to waste huge its protective galvanizing coating amounts of energy. Bringing in too could promote unhealthy mold or much cold air in the winter, or too slime growth within the air handling much hot, muggy air in the summer, units. forces a great energy load on the boiler or the air conditioning Inspect and maintain fans and systems. A disproportionately high blowers amount of energy is needed to temper hot or cold ventilation air Establish a periodic or seasonal requirements for the rooms while maintenance plan for all fans and occupied. Remove any cardboard or “stuffing” blowers. Document the many types installed by the occupants due to and location of the fans. Be sure to There are many ways that facilities annoying or drafty air discharges on include all lavatory exhaust fans. personnel can help to reduce energy people. Blocking off the intended air These are typically overlooked and waste and redirect saved energy flow by uncomfortable occupants can create unhealthy air in the dollars. Some of the best, simplest forces more air to be delivered to the lavatories. Keep the blower wheel or and lowest cost options for remaining rooms on the system. fan blades clean to maximize the increasing the efficiency of the Verify that the duct systems are open efficiency of the equipment. HVAC systems are: to all the original design rooms and Centrifugal blower wheels frequently properly balanced to prevent collect enough dirt on the bladed to Inspect and maintain all air duct occupants from taking matters into reverse the designed curvature of the systems their own hands. blade. Periodically inspect supply and Clean heating and cooling coils Establish a documented service plan return ducts for air leaking into or out for any kitchen and food services of the duct seams. Also look for open Dirt and dust are great insulators on fans and blowers. Fans used in ducts that may be disconnected and coil surfaces. Even a fine coating of cooking hoods are critical to keep open above false ceilings. Seal all dust on a coil can result in a reduced cleaned of grease residue to prevent leaking duct seams with seam sealer heat exchange, causing the system a fire in the kitchen or the exhaust and cap or repair unused or to run longer to meet heating or duct. The kitchen hoods and fans abandoned branch taps dumping air cooling needs. Keep the coils clean should be serviced by a professional into the ceiling cavities. By repairing throughout the changing seasons. cleaning company familiar with the leaks the air will go where it was fire codes related to proper and safe designed to go and energy will not be During the cooling season, moisture system functioning. wasted. collecting on the cooling coils is collected by drain pans and drained Inspect and replace worn or loose Verify the integrity of the insulation out of the air handler. Drain lines can V-belts on belt driven fans and on insulated ducts. This is especially accumulate dirt or become plugged, blowers. A loose belt on a blower can true for ducts that are made out of causing moisture carryover into the slip, squeal and waste motor rigid insulation board. It is common discharge side of the coil. Plugged horsepower in addition to burning up for duct sealing tape on rigid drains can also cause the drain pan the belts. Friction between the loose Hartford Steam Boiler Page 3/4 Optimizing Your Heating, Ventilating and Air Conditioning Systems belt and the sheave can generate If a motor requires replacement, Verify that the number of belt enough heat to burn the belt and trip consider replacing it with a premium grooves in the sheaves match the the fire alarm causing a building efficiency rated motor. It can save up number of V-belts installed. Multiple evacuation. Make sure the belts are to 8 percent energy compared to a grooved sheaves require the same properly aligned and tracking standard efficiency motor. Also, number of belts to transfer the properly to prevent premature belt check with the HVAC service required horsepower from the motor and bearing wear. Keep all motor provider to see if any motors in the shaft to the driven equipment shaft. bearings and driven equipment shaft building could be retrofitted with bearings lubricated at the scheduled variable frequency drives for energy Establish an air filters maintenance frequency provided by the savings. Make sure all motors are program manufacturer. only operated when performing a needed task. Motors are typically Apply a consistently executed filter Maintain and properly control all large loads and can quickly waste a maintenance program to help motors lot of money if left on when everyone minimize dirt and dust deposits on goes home for the night. Invest in a fans and coils. In addition, keeping Verify that all fractional horsepower simple, economically installed the filters changed at the proper motors are functioning properly. controller for the largest uncontrolled frequencies will help to improve the Although they do not consume a motors in the building. indoor air quality. large amount of energy when they run, they all perform a necessary Maintain all belts and sheaves Determine the optimal frequency for HVAC function. The smaller motors changing the filters based on regular used in small room unit ventilators, Inspect the motor and driven inspections of the filter material. Not heat pumps or stand-alone room air- equipment pulleys or sheaves to all filters need to be replaced at the conditioners have a shorter rated life make sure the V-grove sides are not same frequency. For example, for a than a large equipment room motor. worn into a concave shape. A worn ventilator unit with an outside air These smaller motors usually fail sheave will not transmit the rated filter and a recirculated-air filter, the from seized motor bearings and then mechanical horsepower from the outside air filter many need to be the motor shaft locks up. When this motor to the driven equipment. Worn replaced half as many times as the happens, the motor will continue to sheaves will cause new belts to be recirculated-air filter. Filter change draw energy but do no useful work. If noisy, wear out quickly and perform frequencies are a function of many left unchecked, these motors can get poorly.
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