Commercial HVAC Systems

Air ducts interconnect, Filtration systems, Air conditioning systems, and fresh air. To a good contracting company, they are sophisticated; they will deliver the “proper” amount of air, and depending on what that air contains or its location also plays a factor in the type of ductwork to be used, such as Galvanized, stainless steel, Flex duct, etc. If it’s high velocity or standard, taking everything into consideration, they may and more likely have valves to control the flow of the air either off, on, or partially open into different rooms with digital controls. You can start seeing how something that looks like a simple duct is actually more complex than it looks, and we can design a solid ductwork system to meet your needs.

Similar to the exhaust fans in your house located in the restrooms, exhaust fans in commercial buildings are used for removing fumes, stale air, cooking air, etc. The removal of air by exhaust fans MUST be calculated, as you can put the room or building into what’s called negative pressure, which would cause problems such as making it difficult to open doors to the building because you have to overcome that negative pressure. Additionally, allowing too much outside air in would create excessive dust buildup in the rooms or building, also increasing air conditioning run times as too much unconditioned air is being forced in, causing higher utility bills. It goes without saying that a good exhaust fan is selected AFTER the client’s needs are known. Then, we can do a calculation that tells us how many air changes per hour are required. Air changes refer to how many times the air in that room or building needs to be changed for new conditioned fresh air. If there are too few air changes and the exhaust fan’s air changes are too slow, then you could get increased Carbon Monoxide, which comes from burning fuels such as gas, propane, car exhaust, or Carbon Dioxide, which comes from people exhaling air. Too much of either can cause health problems such as headaches, nausea, or sickness depending on concentration levels. These levels can be found in gyms, enclosed buildings with large groups, offices, etc. Exhaust fans are important and MUST be calculated and designed correctly, something we can do. AC units have economizers which operate by opening and closing depending on Carbon Dioxide levels, as there is starting to be a mandate for the installation of such systems for the previously mentioned reasons.

Heat recovery ventilation (HRV) and energy recovery ventilation (ERV) are important and similar. When you bring fresh air inside your building, it comes in with the moisture and temperature that are outside. For example, if you’re keeping your building at 75°F and the outside temperature is 100°F, that means you are bringing in fresh air from outside that is hotter than the air temperature you’re trying to maintain. This makes your AC work harder as it needs to cool that 100°F air down to 75°F, wasting energy. Here is where a Heat Recovery Ventilation system comes in. They have different efficiency levels, but they all work the same since you’re bringing air in, the building’s air has to come out also. An HRV system takes the 75°F cold air and transfers that temperature into the 100°F outside air that’s coming in. Not all of the 100°F air will come in at 75°F; once that energy is transferred, it will be somewhere around 80°F. But it’s much easier for an air conditioning system to cool down 80°F to 75°F than it would be to cool down 100°F all the way to 75°F, thus saving on energy bills. These units also need to be calculated for use, and that is something we can do. Now that you know how a heat recovery ventilation works, an Energy Recovery Ventilation does the same function but also transfers the moisture from the air. It’s usually used in more humid climates, while the Energy Recovery System is used in drier climates.

A standard comfortable indoor air temperature in a building, on average, is roughly 75°F, with humidity ideally between 40% to 50%. A humidifier adds moisture to the air, while a dehumidifier removes it. It’s important to have a humidifier or dehumidifier system in place where humidity levels exceed 50% or fall below 40%, such as in hospitals, spas, or for specific applications like labs, or where a person has a medical condition. If it’s too dry, problems like itchy eyes, dry skin, respiratory problems, and drying out of wood can occur. Too much humidity can lead to sweating, mold growth, bacteria and virus growth, among other issues. Other places and items that require special humidity control include meat markets, fish displays, vegetables, and places with large pools such as schools, YMCA’s, and grow houses.

For proper design of humidity control systems, contact us.

Your air conditioning system is NOT designed from the factory to be an Air Filtration System. It’s designed to cool, heat, and dehumidify the air, not filter it. The purpose of a filter from the factory is to filter dirt and other larger particles out from clinging into the Evaporator coil, which is the part that gets cold and cools your air. However, you CAN design a duct system that CAN handle a more restrictive type of air filter that will stop small particles from circulating around your building. Air Filters & Air Filter Systems are not well understood by the general public. MOST AC SYSTEMS DO NOT deliver their rated capacity. In other words, a 5 TON system usually doesn’t deliver its Rated 5 TON capacity into the building, especially if the system has too much of a restrictive air filter, among other factors such as return or supply ductwork being too small, ductwork air leakage not making it into the conditioned space, etc., causing high amounts of wasted energy bills. The type of filter to be used for the client’s needs needs to be designed and calculated so that there is enough surface area where air can get through and not stop airflow, allowing the air conditioning system to deliver its RATED air capacity by the manufacturer. It’s sort of like putting a partial board over your car’s intake air and stalling it. The more pollutants that filter is able to stop, the more weaves there are to that filter, the smaller the micro holes are in that filter, the less the air can get by. The more that board is closing that car air intake until that car can no longer deliver its Manufacturer-rated horsepower. The same goes for AC systems; the more restrictive, the less they are able to deliver the AC rated Tonnage capacity. We can calculate & design a good filtration system, whether it’s HEPA rated, and you’re trying to clean or purify the air; we can do it.