What Causes Fog in Underground Parking Garages?
3 Answers
Because the water vapor in the underground garage has reached saturation, as the temperature rises during the day, the air temperature in the garage also increases, and the saturation vapor pressure of water rises accordingly. In theory, this should prevent the formation of fog. However, due to the presence of condensed water on the floors and walls of the garage, to maintain the balance between the gas and liquid phases, the condensed water begins to evaporate, thus creating fog. Below are some parking precautions: 1. No parking in areas with no-parking signs: No-parking signs indicate that all vehicles are prohibited from parking temporarily or for an extended period within the designated area. 2. No parking within yellow grid lines: Yellow grid lines indicate that parking is prohibited in this area for any reason. These are commonly found at intersections, entrances, and exits. 3. No parking on roads with yellow solid lines: Parking is prohibited on roads marked with yellow solid lines. The length of the yellow solid line indicates the extent of the no-parking zone. 4. No parking near bus stops: Parking is prohibited in areas such as bus stops, gas stations, emergency stations, and near fire hydrants.
Every time I park in the underground garage after work, especially on rainy days, it's foggy inside, which is really annoying. This is mainly because the garage temperature is higher than outside, particularly in summer or warm seasons, causing moisture from outside to condense into fog upon entry. The garage entrance acts like a funnel, drawing in humid air that doesn't ventilate properly, leading to moisture condensation. After living here for a while, I realized the garage design didn't account for airflow circulation, such as too few vents or poorly placed ones. Normally, when cars enter, the exhaust from the tailpipe adds humidity, making the fog denser. I suggest garage owners install more exhaust fans or regularly open doors for ventilation to let the moisture escape, preventing visibility issues that could lead to accidents like hitting pillars—it's a safety concern. Actually, for a simple fix, I tried placing some desiccants myself, but the effect wasn't significant. It's best to have a professional inspect the structure.
Having managed garages for so many years, fogging issues are quite common. It's usually caused by insufficient ventilation, such as aging fans or clogged ducts, which prevent moisture from escaping and allow it to accumulate. Additionally, poor sealing around deep wall crevices or door frames in the garage can let rainwater seep in, bringing even more moisture. This is especially severe during the rainy season, when the floor becomes slippery. Our property management always emphasizes maintaining drainage ditches to prevent standing water from worsening the fogging. In fact, external environmental factors also play a role—if there are water channels or high-humidity areas near the building, the garage is more prone to being affected. Moreover, vehicles coming in and out bring in moisture, further contributing to the fogging. The solution is to regularly inspect fans and vents to ensure proper airflow, which can prevent many problems.
