While HVAC coatings are often the most cost-efficient insurance for the longevity of your air handling system, there’s much more to them than just increasing your building’s systems’ lifespan. The rising demand for antiviral coatings, for instance, was triggered by COVID-19 pandemic and tenants worried about their well-being from airborne diseases. In the same category, antimicrobial and antiviral coatings can make a huge difference for indoor air quality and occupant safety. There is a number of HVAC coatings which drive energy savings, primarily desiccant-coatings. Found on rotary heat exchangers, they enable recovering heat and moisture, which then helps building owners to save on operational cost. And of course, there are also numerous coatings which can help reduce corrosion and maintenance of systems. Here’s everything you need to know about commercial HVAC coatings, the way they can save you money, and protect the air quality inside your building. Read on!
The five ways in which HVAC coating protects health and saves money
#1: Higher energy savings from heat exchangers
A rotary heat exchange wheel transfers heat and humidity between incoming air supply and exhaust air. Desiccant coated heat exchangers can salvage building humidity, transferring it back to the fresh incoming air, saving overall energy usage for cooling and heating. In winter, thermal wheels recover energy from heating and humidifying the indoor space to precondition the incoming, cold, dry air. In summer, on the contrary, rotary heat exchangers pre-cool and dehumidify the incoming air. Just as they capture and release temperature, they do the same with the moisture, also known as latent energy. Thermal wheels can achieve this goal thanks to the use of a desiccant coating.
The desiccant medium is hydrophilic, and it captures water vapour across its vast internal surface area. As the wheel spins, opposing airstreams form a gradient between temperature and moisture. Since the opposing airstreams have different temperatures and moisture contents, the vapour pressures on their surfaces differ. As a result, the presence of desiccant coating helps to humidify cooler air and dehumidify warmer air. The benefits of this HVAC coating quickly become tangible as research has shown that desiccant layers significantly improve performance and lead to energy savings. Swiss Rotors offers different kinds of desiccant coatings, which can vary by price, sorption quality and optimal heat recovery efficiency. In the sorption type, both foil layers are desiccant coated, offering high latent recovery levels and hygienic quality of the rotor thanks to the presence of 3A carbon molecular sieve. Another popular recovery option – enthalpy – combines different media types. One foil has a desiccant coating, and the other comes in standard aluminium, achieving moderate latent heat recovery qualities at a cost-effective price.
#2: Healthier and safer indoor air quality (IAQ)
Antimicrobial coatings are hugely popular in commercial building applications due to the spread of COVID-19. The European Centre for Disease Prevention and Control (ECDC) reports that the virus can be airborne up to three hours, four hours on copper, 24 hours on cardboard, and up to 2–3 days on stainless steel and plastic. Other studies have shown that virus particles can survive for up to 72 hours on surfaces made of plastic and stainless steel. This fact has led to a rising interest in antimicrobial coatings for different materials used in buildings. HVAC systems use the same coatings applied in high-contact surfaces like door handles, eliminating microbes that come into contact and preventing their spread. These coatings have the ability to kill a variety of microorganisms and reduce the risk of spreading the virus. And as the global economy is emerging from hibernation, engineers are developing more radical technologies to keep the virus out of offices – like silver silver-based coatings that kill microbes on contact. At Swiss Rotors, our product engineering team has been working on a similar solution for a while – we’ll soon share more details, so please stay tuned. Public areas, hospitals and lab applications have already used similar versions of these coatings in their ventilation and air conditioning units, offering another backup layer for health security.
Harmful dust and mould are also top considerations for HVAC units, and that’s where coatings can eliminate the buildup of such debris. Instead of harsh cleaning chemicals, which means regular servicing, an annual application of these coatings makes it cost-efficient to protect your HVAC system passively. HVAC ducts are particularly vulnerable to debris and mould, and coatings provide a sealant for any porous materials where debris can get trapped. In hot, humid climates, these HVAC coatings are critical for preventing microbial growth and extending the longevity of the full system.
#3: Longer lifespans of HVAC components
Applying the right HVAC coatings will help you delay the moment when you have to replace your parts due to corrosion and wear-and-tear. Some systems can survive decades longer than they would without the application of anti-corrosive coatings. There are many types of anti-corrosion coatings, depending on pollutants and byproducts of
your indoor environment.
Pitting corrosion in HVAC metals often comes from fluoride and chloride ion exposure which usually takes place when commercial cleaning products come into play. Annual cleanings and coatings can eliminate pitting corrosion, caused by condensation.
Formicary corrosion is an issue related to AC units, where the coils corrode over time from exposure to acids, water, and oxygen. Once again, coatings completely reverse this issue when appropriately managed, increasing the lifespan of an overall HVAC system triple-fold.
#4: Ease of maintenance
Cleaning and preparing surfaces for HVAC coating processes is a simple, one-person job building operator can perform annually, or bi-annually depending on their property operations.
Coated surfaces can be easily cleaned with a pump sprayer for flat surfaces, or pressurised air for tighter spaces between air handling units and fan systems. Applying protective coatings can be done as early as at a post-fabrication stage, making it far easier to manage new installations in the future.Advances in spray-on coatings reduce manufacturing costs and make it possible to apply customised coatings that fit your unique needs. For instance, hotter, more humid climates require thicker antimicrobial coatings, as opposed to dry, desert climates which may want resistance to heat adsorption. Ocean areas near saltwater prefer anti-corrosive coatings, due to salt content in the air eroding HVAC metals more quickly than other environments. All of this is to say that coatings are highly flexible, customer-specific products that building owners need to be familiar with.In general, there are four types of coatings for the HVAC industry:
- polyurethanes,
- epoxies,
- fluoropolymers,
- silanes.
Traditionally, these HVAC coatings had to be applied at the manufacturing stage. But today, they can come in convenient and easy-to-use aerosols or spray forms. Your HVAC technician can coat components onsite before installation, and you can order them from local or trusted vendors to save on costs.
#5: Lifetime cost-savings
All of these factors add up to creating a sustainable, long-lasting and resilient solution for thermal heat exchangers and HVAC air handling systems. Cost savings come from lower energy consumption building owners need to use to heat, cool and humidify indoor air. In addition, HVAC coatings reduce the operational costs necessary to maintain and replace HVAC parts, which also means less downtime. Thermal wheels can sometimes be vulnerable to corrosion because of their thin and intricate structures, or level of pollutants coming from exhaust air. 3A carbon molecular sieve coatings finely seal off the heat exchanger from the environment, without affecting heat transfer and pressure drop. With minimal investment, modern coating technologies can significantly extend the lifespan of a building’s HVAC system – generating even more savings in the long-term.
The real significance of HVAC coatings
There are multiple ways in which the right choice of an HVAC coating can support building operations. From increasing energy savings and improving IAQ to extending the lifespan of components, simplifying maintenance, and decreasing costs – their benefits are immense.
Contact us if you’d like to learn more about how our rotors and coatings can help you generate more savings and create better indoor air quality.