The seasonal transition leading up to summer is the ideal time to prepare a restaurant’s HVAC system as winter inevitably creates unintended consequences for slumbering mechanical equipment. As customers seek to escape their own hot kitchens for the cool haven of a new or favorite restaurant, ignoring preventative maintenance now can lead to catastrophic problems later on that compromise customers’ and employees’ comfort or, even worse, threaten their health and safety.
Restaurant facility managers need to verify that their HVAC equipment can handle wide temperature swings while also taking advantage of possible “free cooling” during the “shoulder seasons.” It is also the ideal time to determine if it is more economical to replace an aging unit before the busy summer season heats up so as not to throw good money after bad by repairing an aging HVAC system that should be retired.
The good news is that the necessary maintenance steps are manageable and relatively speedy to perform. Here is a five-step checklist for preparing an HVAC system for the sizzling summer season.
External inspection
Start by inspecting the overall operation of the mechanical equipment and checking for any damage resulting from harsh weather. Look for visual signs of damage from ice, snow, hail, rain and other elements, as well as the integrity of the HVAC cabinet, particularly with rooftop systems.
Hail storms can occur at any time of year, causing damage to condenser coils. Inspect the HVAC unit after every storm, and also check for visual signs of oil or refrigerant leaks that may have resulted from the natural expansion and contraction from fluctuating temperatures. And perhaps the most overlooked step in the inspection phase is making sure the air flow across the condenser and evaporator coils are unrestricted. Clean coils and filters are imperative to the proper and efficient operation of a unit. A blocked outside air filter or restricted coil will surely impede system performance or lead to system failure if not corrected.
Electrical check
Before opening and inspecting any electrical service panel or disconnect, be certain that the power has been turned off and secured. Electrical services should only be completed by an experienced technician with the proper protective equipment.
Check the electrical service disconnects to ensure that all connections are properly tightened and show no indication of discoloration, which could suggest a pending failure. Disconnects should operate smoothly and show no sign of overheating. Repair any damaged wire that could fail, resulting in electrical damage to the equipment.
It is also a good time to inspect the breakers and fuses, check and replace thermostat batteries and ensure temperature readings are accurate. Those with more electrical expertise may also want to measure the electrical currents while the equipment is operating to ensure compliance with the manufacturer’s specs.
Ventilation
Frequently inspect outside air filters, but now is perhaps the most critical time to clean air filters to enhance ventilation for the summer months. Compromised filters put a strain on HVAC systems, causing the equipment to work harder to remove heat and therefore wasting energy, elevating costs and leading to premature system failure. When drawing in outside air, it is especially critical that the outside air filter is clear of large particulates like leaves and feathers. The goal is to maximize the life of the return air filters without being so frugal that it puts the HVAC system, and more importantly, customer and employee health, in jeopardy.
Check the air balance between the make-up and exhaust systems to ensure that cooking fumes and odors are properly exhausted. Poor air circulation can create a draft in the dining areas causing the entrance doors to malfunction when opening or closing.
Environmental exposure
In addition to ensuring that the air filtration equipment is working properly, check that the outside air introduced into a restaurant complies with local ventilation codes, is not drafting in unwanted odors from nearby exhaust systems and is not unintentionally increasing CO levels that could affect customers and employees. It is also a good time to check temperature rise and fall across the condenser and evaporator, and set the amount of outside air being introduced when mechanical cooling is required.
If the levels aren’t balanced, the restaurant owner risks putting customers’ and employees’ health at risk, in addition to the implications of not meeting OSHA requirements. Alternatively, if the imbalance is causing too much air to enter the conditioned space, customers comfort is adversely affected, while leading to increased energy costs.
Economizer performance
Most rooftop HVAC systems these days come equipped with economizers that allow the units to take advantage of “free cooling” from outside air when temperature and humidity permit. Make sure the economizer sections are operating smoothly, and adjust and lubricate as needed to ensure the dampers open and close optimally. Also check the linkages for binding, thermostats and settings for accuracy, and sensors for proper operation.
Because an economizer can reduce mechanical cooling by up to 75 percent, a well maintained economizer could result in significant savings in utility bills.
Final thoughts
Winters create unseen problems with HVAC systems, and summers turn those problems into potential business catastrophes by putting undo stress on systems that are not properly maintained. Maintenance is always a more economical solution than reacting to a problem. Taking advantage of the spring-summer transition period to properly maintain a cooling system is the best way to ensure the continued comfort and safety of customers, as well as keeping ever-rising energy costs in check.
