Direct Vent Vs. Standard Vent Water Heater: Which One Is Better?

Matthew Mountain
by Matthew Mountain

Water heaters can be vented in a variety of ways, but some systems require specific ventilation configurations. In this article, direct vent water heaters will be compared with standard atmospheric vent water heaters, as this way the reader will be able to select the best water heater for their home.

Your water heater’s venting configuration will ensure your system works efficiently and safely for many years. When you don’t know what kind of venting is required, it’s best to get in touch with a professional plumber, as they will know which kind of venting is right for your system.

Direct vent water heaters and standard atmospheric vent water heaters are both efficient, but direct vent water heaters are more flexible while costing less as well. Direct vent water heaters also don’t rely on vertical gas-powered venting, which means one doesn’t have to worry about a backdraft when they utilize a direct vent water heater in their home.

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What Is a Direct Vent Water Heater?

Direct vent water heaters utilize special coaxial venting, which means there’s a chamber for intake air and a chamber for exhaust both housed within a single piece of vent. These water heaters are powered by gas, and they work well in homes that lack proper ventilation.

These heaters draw in air from the outside, and then this air aids in the combustion process. Once the water inside a heater is sufficiently hot, excess heat and exhaust fumes are vented back outside and away from the home.

Direct vent water heaters utilize ventilation systems that connect these heaters to the sides of homes and buildings. They also pull and push air, so there will never be a chance of a backdraft occurring. It’s safe to install one of these water heaters, and these gas-powered systems are stronger than electric water heaters.

If you need help with installation, it’s best to get in touch with a professional plumber. They’ll have the tools, know-how, and experience necessary to properly set up a direct vent water heater.

The Pros and Cons of Direct Vent Water Heaters

Before you go through with a direct vent water heater installation, you should know the pros and cons of these systems. These are outlined below. Consider them all in totality before you purchase one of these water heaters.

Pro: It Doesn’t Cost a Lot to Operate

These water heaters run on gas, but because they utilize a special heating process, they are more efficient than power vent water heaters; these run on electricity. If you want to avoid a high electricity bill, then you should stay away from an electric water heater and instead get a direct vent water heater.

Pro: Affordable Installation

Since these systems don’t require fan installation, they are cheaper to install than say, for example, power vent water heaters. Furthermore, because they utilize sideways ventilation, you won’t have to put a hole in your roof. Instead, you can set up a system pretty close to the wall where the vent will exit.

Pro: Smooth & Quiet Operation

Again, the absence of a fan makes these water heaters better than their electric counterparts. Direct vent water heaters simply “breathe” in and out quietly, and this will not distract you even if you’re near the vent for a long time. Some water heaters are quite noisy, and the fact that a direct vent heater runs near-silently is one of its biggest advantages.

Con: Direct Vent Water Heaters Can Be Less Advanced

Direct vent water heaters can be less efficient than power vent heaters, but this isn’t the case across the board. The reason why some direct vent water heaters fail to match up against their electric counterparts is that these latter water heaters employ more high-tech components.

In some ways, direct vent systems are superior to other kinds of water heater, so one must take all of the qualities a system possesses into account before giving it an efficiency rating.

Con: Some Direct Vent Water Heaters Require Vertical Ventilation

Some direct vent water heaters require pre-existing ventilation. You’ll have to have a vertical vent or a chimney already in place for these direct vent systems to work.

The vast majority of direct vent water heaters, however, utilize the sideways ventilation networks that were discussed before, and these are much more cost-effective and efficient than vertical ventilation.

What Is a Standard Atmospheric Vent?

Standard atmospheric vent water heaters are what you’ll find in most homes, and these heaters vent exhaust through a system of vertical metal ducts until the exterior of the home is reached. The vent system that a standard atmospheric vent water heater utilizes can be shared by another atmospheric vent appliance—the most common one being a furnace.

These systems are powered by rising hot air, and this is why vertical ventilation is so important. As hot exhaust rises, it’ll eventually reach a chimney or exit spout, and then it’ll be released into the air.

The Pros and Cons of Standard Atmospheric Vents

Like direct vent water heaters, atmospheric vent water heaters have upsides and downsides. Since these water heaters have been around much longer than the direct vent systems which were already discussed, it’s well known what they can do.

Consider the pros and cons here before purchasing and installing a standard atmospheric vent water heater.

Pro: Not Dependent on Electricity

What’s nice about standard atmospheric vent water heaters is that no electricity is required. This means you don’t have to worry about being without hot water when the power goes out.

Pro: Easy and Affordable Replacement

Since atmospheric vent water heaters have been around for a long time, you don’t have to worry about a difficult replacement. In fact, replacing these systems is often more affordable than maintaining them over a long period of time.

Con: Wasting Energy

Sometimes atmospheric vent water heaters can waste energy. There always has to be a certain amount of gas in the system, and this means that fuel is perpetually being burned as long as the system is on.

Then there are instances when gas rises up and out of a chimney along with excess exhaust. This is an unavoidable problem, as it’s largely due to how these systems are made.

Con: Wasting Money

With wasted energy comes wasted money, and standard atmospheric vent water heaters can also be money pits if they frequently require maintenance. Say, for example, your system routinely leaks gas. Not only will this create a huge scare but it’s a system problem that’s hard to address sometimes too.

If you didn’t rely on a system that requires gas-powered ventilation, you wouldn’t have to deal with this problem.

Con: Standard Atmospheric Vent Systems Can Be Dangerous

In general, these systems work quite well. But in an instance when gas does not rise properly, it can build up and then leak out into your home. This might give you a headache if you’re exposed to the gas for a long time, but it’s also very dangerous. With a vent that blows exhaust and excess heat sideways through the side of the home, this is not a problem.

Do Power Vents Have an Edge?

Power vent water heaters utilize an electric blower fan, and this fan is usually installed at the top of the water heater. Because of this fan, this water heater must be near an electrical outlet. The blower pushes exhaust and excess heat through the venting system, and venting can either be vertical or horizontal.

These are flexible systems, and this is the edge they have over standard atmospheric vent water heaters. Direct vent water heaters have some flexibility, but not the kind that power vent water heaters boast.

Related Questions

What is a power direct vent water heater?

A power direct vent water heater goes great in a place that doesn’t have enough room for air-based combustion. These systems are also ideal for those who need flexibility and affordable installation. They utilize blower fans along with sideways ventilation.

How does gas-powered ventilation work?

Atmospheric venting is based on the principle that hot air rises. For this reason, vents must be vertical or sloping upwards, as this way hot exhaust can rise up through the vents and out of the home.

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Final Note

In the end, direct vent water heaters have a lot of good qualities that standard atmospheric vent water heaters don’t have, but this doesn’t mean these latter water heaters are ineffective. They can be quite effective in the right homes, but direct vent water heaters are more flexible—and this flexibility doesn’t come at the cost of efficiency.

You can expect to pay more for an atmospheric vent water heater installation too. A direct vent water heater, on the other hand, can be set up pretty close to the spot where the vent will be exiting the side wall. The less you have to spend on venting, the less the cost of installation will be.

Direct vent water heaters also take the backdraft problem out of the picture, as these systems release exhaust and excess heat sideways. In other words, they don’t utilize gas-powered vertical venting.

Matthew Mountain
Matthew Mountain

Matt loves everything DIY. He has been learning and practicing different trades since he was a kid, and he's often the first one called when a friend or family member needs a helping hand at home. Matt loves to work with wood and stone, and landscaping is by far his most favorite pastime.

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