If you’ve ever been in a commercial restroom, you probably noticed that there is either an up- or down-draft vent. The reason for this is that the VAV (Ventilation, Air Handling, and Ventilation) system offers one of two different ways to handle toilet exhaust. You also might be asking “Can a toilet vent be upstream of the toilet?” as it seems like it would make more sense for the exhaust to be downstream of the fresh air intake. There are many things to consider when deciding on whether a VAV system should exhaust from above or below your toilets. Each option has its own benefits and drawbacks. Which one you choose will depend on your specific needs and space restrictions. Let’s take a look at which way is better for your VAV system and why.
Can a Toilet Vent be Upstream of the Toilet?
The short answer is yes! But you may want to read further to see if one of the other options is more beneficial for your specific situation. Every VAV system has two components that are vital for its proper operation. First, you have the air handler. This is the component that houses the air source that is responsible for providing the fresh air to your restroom. The second component is the terminal. It is responsible for the removal of the exhaust that exits the restroom. The terminal for a VAV system is typically located above the toilets and above the urinals. Each terminal has two ducts, one for the fresh air and one for the exhaust. The decision to place the terminal above or below your toilets will determine what duct is used for your toilet exhaust.
How an Upstream Vent Works
The duct that brings fresh air into the restrooms of your commercial space is the primary component of your VAV system. It usually enters the restroom through the drop ceiling and travels along the joist work on your ceiling. If you have an overhead duct, it will continue until it reaches the terminal. The terminal houses the blower that is responsible for distributing the fresh air throughout the restroom. The other duct that is part of the terminal is the one that is responsible for removing the exhaust from the restroom. This duct has two different ways it can operate. The first way is by exhausting below the toilets. This may be the best option if you don’t have the room to place your terminal above the toilets. It also may be required if your roof is not high enough to make room for an overhead terminal.
Why You Might Choose an Upstream Vent
There are many benefits to choosing an upstream vent for your VAV system. One of the biggest benefits to this method is the reduced noise. This is because the blower that controls the fresh air is located outside the restroom. That means that there is much less noise coming from the terminal itself. The loud humming noise that you’re likely familiar with is greatly reduced. Another great benefit to this system is that you can use a larger blower. Since the noise of the blower is not in the restroom, you can use a larger and more powerful blower than if you had placed the terminal above the toilets. This can save a lot of money since the terminal is the most expensive part of the VAV system.
Why a Downstream Vent May be Better for You
There are also many benefits to choosing a downstream vent for your VAV system. One of the biggest advantages of this system is that it can handle much more air (and therefore more toilets) than the upstream vent. The terminal for this system is located below the toilets. This means that the exhaust for the toilets is traveling up against gravity. This extra force makes the toilet exhaust much more powerful and efficient. Another great advantage to this system is that each duct can be individually controlled. This means that you can shut off the duct from below the urinals in order to save on energy while keeping the duct below the toilets open. This can save a lot of money on your monthly utility bill.
When choosing between an upstream or downstream vent for your VAV system, it’s important to consider your specific situation. If you have the space above the toilets to place your terminal, the overhead vent may be a better option. The overhead terminal can use a larger blower that is much less noisy. If you don’t have the space above the toilets, the downstream vent may be the better option. The terminal below the toilets can handle much more air and has two individually controlled ducts. This can save plenty of money each month on your utility bill.