Air Balance

Air Balance

We have recently had a nice decrease in temperature. Thank goodness! But the humidity has remained for the most part. Humidity brings with it a plethora of problems. Mold and decreased “creature comfort” are the biggest. Condensation on vents, coolers, and any cold service is another. Higher than normal utility bills can also become a concern.

This brings me to the point of (unfortunately) not sitting around an enjoying the paradise weather that we enjoy this time of year. We can always decrease costs while increasing guest comfort and a customers experience at retail and, most specifically, restaurants.

The issue at hand is air balance. A restaurant has exhaust fans, outdoor supply air fans and air conditioners with fresh air make up.

The same amount of air being expelled by the exhaust fans (typically 10-30 tons per hour) must be replaced. Otherwise the building will be in a negative balance and will draw air in through doors, windows and cracks and gaps in the building. The way that the air is replaced is by using make up air fans that form curtain of air at the front o the cooking equipment. This curtain helps t capture the grease and smoke and force it to the exhaust fans. The air that you feel blowing at he front of the deep fryer, grill, etc. s the make up air fan. This air typically makes up 80-95% of the air being exhausted. Using the fresh air intakes on he a/c units makes up the remainder. Or it is brought in through the doors and windows. This is where the problems begin.

When the air is brought in through windows, doors, etc. if not filtered and brings with it heat and humidity. When the humidity comes into a cool restaurant it will need to be cooled (higher energy costs) ad as will release the excess moisture due to the change in relative humidity inside the building. This condensation will result in uncomfortable conditions and ultimately mold formation.

Many times, proper building balance can be achieved by making sure that belts are tight, filters and blower wheels are clean and return air grills are not obstructed. A quality preventative maintenance program should keep everything in check.

Is your building properly balanced?

A simple test is to make sure that all doors and windows are closed ad then crack one door open approximately one inch. Light a cigarette lighter and hold it at the gap in the door. The flame should bend slightly towards the outside. If it bends towards the inside of the building then you have a negative building balance. If it does not stay lit then there a strong balance issue. It would then be time to clean the coils, blower wheels, and filters and tighten or replace the belts. IF there have been various motors and/or a/c units changed over time ad the proper balance cannot be achieved by a proper maintenance then you will need to have a reputable hvac company rebalance the building by changing pulley ad motor settings, etc. If you routinely d the simple balance test with a lighter then there is very little chance that you will end up with a “sick” building from improper motors, etc. being installed.