August 22, 2019
Why should you retrofit your HVAC System?
There’s an age-old argument about whether something new is necessarily better than its older version just because it’s more recent. While one could argue that it’s not always the case, the claim of newer being better definitely applies to heating, ventilating and air conditioning systems, or HVACs.
Why is this important? Well, unless you’re running a business with a very energy-intensive type of operation – like a steel mill or data center – chances are excellent that heating and cooling your building takes up the largest slice of your energy costs. In fact, the U.S. Department of Energy reports that heating, cooling and ventilation account for about 40% of a typical commercial building’s energy bill. Since energy represents 19% of the total cost of running the average business, HVAC expenses equate to 7.6% of a business’s overall expenses. A recent DOE study estimated that upgrading a commercial building to a new, energy-efficient HVAC system could save from 22% to 56% on heating and cooling costs, depending on the building’s size, use, local climate and local utility rates. In addition to those energy savings, utility and government-sponsored incentive programs may provide rebates for new HVAC systems that meet specified energy efficiency standards.
Advances in energy-efficient HVAC technology over the last few years have largely been driven by the desire of customers to reduce their energy costs, protect the environment and make their buildings healthier and more comfortable. Equipment manufacturers responded to their customers’ wishes by incorporating state-of-the-art technology into their system designs. This involved not only improvements in the components of the HVAC units themselves, but the integration of “smart” thermostats, energy management systems and automation that can diagnose problems with the system and alert the building’s management when maintenance is needed.
The innovations in HVAC technology aren’t just about energy-saving measures. While those measures help the environment by reducing the amount of electricity that must be generated – and the greenhouse gas emissions that go with it – new HVAC technology also benefits the environment by using refrigerants that no longer contain ozone-damaging chemicals (which also save energy because they require smaller compressors) and the incorporation of energy storage or renewable energy resources like solar and geothermal. The environment within the building is also improved because many of today’s HVAC systems include advanced air filtration that cleans the warmed or cooled air of dust, pollen and other particulates before circulating it through the building.
Energy savings can sometimes be achieved by using the planet’s own energy to help keep your building comfortable. Geothermal HVAC systems take advantage of the relatively constant temperature deep below ground level to moderate the temperatures above ground that change with the seasons. These systems have a series of pipes that are installed deep underground, creating a loop to the surface. The pipes are filled with water that flows through the loop and is heated or cooled (depending on the season) by the more moderate underground climate before being pumped back to ground level, where the air that’s been exposed to the more temperate water can be circulated through the building. Water-filled pipes also come into play with solar HVAC systems, although these pipes are installed well above ground (like on rooftops). The pipes contain a mixture of water and antifreeze that is heated by the sun’s rays and then run through a heat exchanger, creating warm air to heat the building. The air conditioning can also run with the help of solar, using either a photovoltaic system to generate electricity that powers a traditional air conditioner or using solar thermal energy to evaporate a refrigerant that absorbs heat and cools the surrounding area.
Energy cost savings can also be realized through recent HVAC technology innovations in thermal storage that shift electric use from more expensive peak periods to less costly off-peak times. One of the prime examples of this technology is ice-making equipment that freezes water during overnight hours when power is cheap and plentiful, and then uses the ice in place of the air conditioner’s compressor to provide cooling during the day, avoiding expensive peak demand charges. Depending on the size of the building and its cooling needs, an ice system can produce and store enough ice overnight to keep a commercial building cool for four to six hours.
One of the energy efficiency technologies that’s quickly gaining popularity as a utility savings solution is Variable Refrigerant Flow, or VRF. Although VRF has been used for decades in Europe and Japan – where it’s found in half of all mid-sized office buildings – it’s only recently caught on in the United States. VRF refers to the system’s ability to regulate the amount of refrigerant flowing to each of its evaporators, allowing for more individualized comfort control within a building. This means that some sections of a building can be chilled while other sections are warmed, so that rooms housing servers or other IT equipment stay cool while office space is heated. VRF also saves energy in situations where sunlight is providing natural warmth to one side of the building while the other side is being shaded.
Another new technology recently making inroads goes by the unusual name of DeVAP, short for Desiccant Enhanced Evaporative. DeVAP HVAC systems use a cooling method based on evaporation – the same principal that makes you feel cold when you first come out of a swimming pool and the air hits your wet skin. DeVAP systems contain an absorbent material that soaks up water like a sponge. A fan then blows air through the material, causing the water to evaporate and cooling the air that is then circulated through the system. A desiccant is used to absorb the humidity, so the DeVAP system can produce the same kind of cool, dry air that an air conditioner does – but using much less energy and no harmful refrigerants.
Any discussion of recent advances in the energy efficiency of HVAC equipment would be incomplete without mentioning the even greater achievements that have occurred in the last few years with energy management technology. Incorporating an energy management system into your building’s heating and cooling functions will maximize your energy savings. An automated control system will constantly monitor temperature and airflow levels throughout your building, and automatically adjust the operation of blowers, condensers, compressors and fans to ensure maximum efficiency. These systems can now be connected to an app that allows a building owner or manager to monitor HVAC performance from their phones and make adjustments remotely if needed. Automated systems can also perform diagnostics that alert the owner or manager to parts of the HVAC system that may need maintenance or replacement. These alerts can prevent system breakdowns before they occur. Energy management functions can be incorporated into a more all-encompassing building control system which also monitors lighting, security, fire protection and other building operations.
The nature of technology is that it continues to innovate as science comes up with new and better solutions to the issues we face. HVAC technology has improved dramatically in recent years as energy efficiency equipment and web-based management systems have reduced energy costs, increased comfort levels and improved indoor air quality. What it all boils down to is that there’s no time like the present to upgrade your business’ HVAC system.