Looking for a simple, low-cost way to help control indoor temperatures and air quality? A gravity ventilation system maybe the solution for your application. This type of ventilation system has been around for about as long as humans have been building enclosed structures. Whether you want to add a gravity ventilation system to a new construction building or want to retrofit your current building, there may be solutions to help. In this article we’ll discuss what gravity ventilation is, why you might consider it, and where it works best.
What is Gravity Ventilation System?
Gravity ventilation or natural ventilation is exactly what it sounds like: ventilation that primarily relies on natural forces. These ventilation systems require little to no energy to help keep interiors cool and comfortable. Gravity ventilation can help not only reduce indoor heat, but can also help improve indoor air quality. This is because these systems offer near-constant air exchange with fresh outdoor air. This is perfect for many types of facilities, like:
- Power plants
- Steel mills
- Forges
- Warehouses
- Paper mills
How Gravity Ventilation Works
Gravity ventilation is the type of ventilation we used in buildings before mechanical ventilation equipment was invented. It relies on nature to help keep interiors cool and comfortable. Gravity ventilation systems utilize wind and the natural buoyancy of air to help remove heat from buildings. With the right design, these natural phenomena can help improve temperatures and air quality inside your building.
Ventilation with Wind
Wind is probably one of the first things that comes to mind when you think of gravity ventilation and cooling. After all, we all know how nice a breeze is on a hot summer day. Gravity ventilation systems help use wind to keep temperatures cool and comfortable in your facility. Typically this involves assessing typical wind patterns and installing intake equipment on the side of the building that receives the most direct wind. In addition, the building will also need exhaust areas on the opposite side so wind essentially can flow through the building and push out the warm indoor air.
Thermal Buoyancy Ventilation
Another natural phenomenon that gravity ventilation systems take advantage of is thermal buoyancy. Most of us know that heat rises, which is the fundamental principle that helps drive many gravity ventilation systems. Hot, humid air is lighter than cool, dry air. Gravity ventilation systems essentially work by allowing hot air to rise and escape out of a building. As hot air leaves the space, cool air comes in to take its place, helping provide cool, fresh air for a comfortable environment.
Benefits of Gravity Ventilation Systems
There are many reasons you might consider gravity ventilation for your building. Industrial ventilation is a serious concern for most types of facilities. Industrial machinery and processes can increase indoor temperatures to uncomfortable and potentially hazardous levels and can also release contaminants that lower indoor air quality. Therefore, ventilation is critical to help keep your environment comfortable, safe, and healthy for those within your facility. Gravity ventilation systems can help achieve this without using electricity.
Some benefits of natural ventilation systems include:
- Lower installation costs
- Low operating costs
- Less maintenance needed
- Reduced environmental impact of your facility
- Keep interiors cool regardless of power outages
As you can see, there are many advantages to choosing gravity ventilation strategies for your facility. In many cases, you can even retrofit your existing building to provide gravity ventilation. Just work with a specialist for proper design of the ventilation system and also for the high quality, long-lasting equipment you need for natural ventilation.
What Equipment is Needed for Gravity Ventilation?
In most cases, gravity ventilation systems start with simple openings in the building’s envelope, such as in the sides and roof. However, simply leaving a gaping hole in your building probably isn’t the best option for your facility. Instead, there is some state-of-the-art equipment to help you make the most of natural ventilation.
Louvers are a popular choice for gravity ventilation systems. These devices have been around since Medieval times, but modern-day options offer cutting-edge design and durable materials to help you achieve proper ventilation. Louvers are essentially an alternative to a glass window. Instead of having glass, they feature angled blades that let air in, but help keep rain, pests, and debris out. In a building, louvers can serve a few different functions. First, they can act as intake and exhaust equipment for cross ventilation using wind. If using the buoyancy effect to help cool your building, louvers help with cool air supply as hot air escapes.
Another common piece of equipment you might need for a gravity ventilation system in your industrial facility is a gravity ventilator. Typically, you install gravity ventilators on the roof to allow hot air to escape outside as it rises. The ventilators help protect your building from rain and debris from entering through the opening in the roof. Also, where you may need reliable output for air exhaust, gravity ventilators may also come equipped with fans to help assist with pulling hot air out of your building.
Gravity Ventilation May Not be the Best Solution for Your Facility
Now, gravity ventilation is a great alternative to mechanical systems for many buildings, but it’s important to understand that it won’t be the best fit for every type of facility. In addition to the many advantages of gravity ventilation, there are also some disadvantages.
For instance, while many mechanical ventilation systems allow you to control the exact temperature inside your building, gravity ventilation systems don’t provide that precise amount of control. Also, with mechanical air conditioning systems, you can often make your indoor temperature lower than the outdoor temperature. With gravity ventilation systems, you will not be able to achieve temperatures lower than outdoor ambient temperatures. Therefore, gravity ventilation may not be the best option if you need exact temperature control or if you live in a very hot climate.
In addition, gravity ventilation systems are almost entirely dependent on climate and weather conditions. This means that some days you may have higher air exchange rates than other days. Also, on extremely hot and humid days, indoor temperatures may stay on the warmer side and be less comfortable for building occupants.
Another drawback of gravity ventilation systems is that they don’t allow you to filter the air coming into your facility. While mechanical systems often use particulate filters to help keep outdoor contaminants and allergens at bay, this simply isn’t an option for gravity ventilation systems, as the filters create too much resistance for the air flow to work properly in a gravity system. So, it’s important to keep these potential issues in mind before deciding on gravity ventilation for your industrial facility.
What You Need for Gravity Ventilation
In addition, not every building will be able to use gravity ventilation systems. This may be due to the local climate or due to the building’s design.
On the climate side, you need an almost constant wind to help with gravity ventilation. Also, gravity ventilation systems work best when outdoor temperatures are significantly cooler than indoor temperatures. This helps hot air rise and escape faster.
In addition, higher ceilings are best for gravity ventilation systems. Low ceilings often don’t provide enough room for hot air to escape quickly enough to keep interior temperatures cool. This can result in the hot air building up and filling the building before it has time to escape.
Cutting-Edge Ventilation Solutions from Eldridge
Ventilation and noise control are crucial for any industrial facility. At Eldridge, we are a leading full-service ventilation company that offers the highest quality ventilation system design, installation, and equipment. We pride ourselves on being an air ventilation company that provides innovative solutions to all your ventilation and noise problems. Contact us today for a free site survey and quote!