What Counts For An Energy-Efficient HVAC System?
Can you imagine how your life would be if there were no HVAC system?
Imagine living in a house without a heating, ventilating and air conditioning (HVAC) system. How are you going to survive the winter months without indoor heat? And how uncomfortable can it get during summer when there is no air conditioning?
Not A Luxury
Unimaginable, right? HVAC systems are undoubtedly a necessary part of life and no longer a luxury. They have become an integral part of what makes homes, commercial buildings, manufacturing plants, indoor stadium or arenas, or even automobiles livable and comfortable.
Comfortable Living And Working Environment
And while the purpose of HVAC systems, commercial, industrial or otherwise is to provide the people working inside the structures with conditioned air in order to have a safe and comfortable living and working environment, what happens if the HVAC systems are not installed properly?
Energy-Efficient HVAC System
Conditioned air refers to air that is clean and odor-free, and that humidity, movement of air and temperature are within specific comfort ranges. This is achieved with the help of an efficiently-working HVAC system, installed properly, and without energy efficiency losses.
Installation Errors Equal Energy Losses
According to a report on a new study conducted by the US National Institute Standards and Technology, the benefits of improved energy efficiency ratings of HVAC systems does not count for anything if the unit is not installed properly. With more efficient heat pumps and air conditioners being developed and offered in the market today, it is expected to reduce the 30% electrical energy consumption devoted to heating and cooling for residential users.
Degraded Performance Due To Faulty Installation
The NIST team reviewed surveys and found that majority of air conditioning equipment subjected to evaluation performed below rated energy-efficiency levels which are attributed to one or more installation errors. Air conditioners, heat pumps and other related equipment exhibited degraded performance as a common outcome due to one particular or combination of faults including:
- leaky ducts
- improper refrigerant charge
- oversizing of systems
- restricted air flow
Leaky Ductwork: Dominant Error
Found to be the dominant fault is leaky air ducts, followed by refrigerant undercharge and incorrect indoor air flow which is a result of improperly-sized ductwork. All these cause increased energy use. In hot and humid climates, indoor relative humidity is increased if there is leakage in the ductwork, thereby reducing human comfort. In such an environment, the occupants usually lower the thermostat to compensate and that would significantly increase energy use.
Oversizing And Improper Installation Of Systems
It is important to determine the right size of the HVAC system for a particular area based on the square footage of the interior space. An over sized system will run inconsistently, turning on and off too frequently rendering it ineffective for heating or cooling. On the other hand, an undersized system will be forced to work doubly hard to try and keep up with the demand. And even as the system runs for extended periods, it won’t be able to deliver the desired temperature consistently and in an efficient way, thus wasting energy.
In addition, HVAC units installed without proper cylindrical vibration isolators can result in annoying noise and vibration which can eventually wear off the equipment, forcing the unit to perform below an acceptable level of efficiency.
Faulty, Leaky Ductwork
The lifeline of a heating system lies in great part to proper ductwork. Improperly installed duct work could mean many things, including:
- wrong ducting materials used
- ductwork has cracks, holes or gaps
- ducting is not properly secured to prevent unnecessary movement
Heated air escapes before it’s vented into the intended space with faulty ductwork. If there are leaks in the ductwork, heated air will cool before it heats your space, causing the furnace to work overtime to reach the desired temperature for the room.
Incorrect Installation Of Exhaust System
Often neglected, the proper installation of the exhaust system for the HVAC unit is critical as it can cause exhaust from the burning of fuel to leak into the space or area to be conditioned. If this happens, it can be a health hazard for the occupants. A properly installed exhaust system is important in expelling the byproducts of combustion in the heating system.
Bottom line, for any HVAC system to be energy-efficient, the critical factors that need to be considered according to industry-recognized standards and procedures are determining the proper size, proper installation of the HVAC components – from the compressors, condensers, pumps, exhaust, fans, furnaces, to steam boilers, water chillers, and cooling towers for large and central systems, and including ductwork and air inlets and outlets.
Is your HVAC system properly installed?