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What Is A Direct Vent Water Heater?

Note: This post may contain affiliate links. This means that at no cost to you, we may receive a small commission for made purchases.

Moving into a new house can be stressful. However, taking a cold shower in that new house is even worse.

Water heaters and their installation in homes are a critical part of the plumbing and electrical maintenance process. It is also crucial for you to know what kind of heater would suit your home the best.

You can look at Direct Vent Water Heaters for your house. It is a water heater powered by gas. In straightforward terms, the Direct vent water heater sucks in outdoor air, uses it for combustion, heats the water, and vents the exhaust gases out.

So, do you think this kind of heater will be the perfect addition to your house? Read on to find out.

How does a Direct Vent Water Heater work?

Direct Vent Water Heaters are gas-powered machines. They use gas to generate heat, which in turn warms up your water quickly.

The exciting part about the mechanism of a direct vent water heater lies in its method of generating heat. The heater takes in air from outside your house and uses it to combust the gas inside.

Once the air outside, rich in oxygen, pours into the heater, it causes the gas to ignite, generating heat. Then, the heat energy warms up your water.

Most direct vent water heaters use natural gas or propane fuel for combustion. Both these fuels are highly flammable, and in turn, are fast-acting agents for generating heat.

These kinds of heaters are well-known for being helpful in spaces with less ventilation because they can easily access air outside the house and use it for combustion. Water heating devices account for approximately one-fifth of your monthly energy consumption.

Therefore, it is paramount for us to know how direct vent water heaters work, their main parts, and their service and maintenance methods. When installing a direct vent water heater, you need to be careful about selecting the perfect location for it.

Venting in Water Heaters

different types of heat ventilation

There is a clear structure that supports the functioning of the water heater. It is built on the foundation of a robust network of vents that allow the movement of gases from the system.

There are multiple types of venting structures – direct vent, power vent, power-direct vent, atmospheric vent, etc. It does not matter which style you choose because all of the above heater types require fresh air to generate heat and need to flush out all exhaust gases from the apparatus.

However, each type of venting is expected to cost differently. Therefore, you need to plan your expenses accordingly. The atmospheric venting is the cheapest to buy, while the power venting structure is significantly more expensive. The price of the direct venting water heater lies somewhere between these two variables.

Buying tips for Direct Vent Water Heaters

Direct vent water heaters are the easiest to install in homes, and that makes them a favorite amongst customers. Steel or PVC pipes are generally used to maneuver the inflow of air and the outflow of combustion gases.

The best installations are those that fit in the heater with minimum turns in the piping. Generally, vertical pipes are used to facilitate exhaust gases.

They ensure that hot gases and fumes rise up and away from the house and enter the atmosphere directly without bothering anyone. Since hot air is lighter than cold air, the hot exhaust gases rise up automatically in the vertical vents and are released easily.

Homeowners are asked to use direct vent water heaters because they are safe. They only use air outside the house, and all exhaust fumes from their vents are released into the atmosphere directly, without any nuisance to the house.

Moreover, Direct vent heaters are designed to ensure that no reverse-airflow occurs. That means a direct vent heater will not allow exhaust fumes to come back inside the house in any scenario.

Simply placing the heater on the outside wall of the house is enough. In addition to all these facets, direct vent water heaters do not need electricity to work. Therefore, you can make use of them even in a power cut.

Direct Vent Vs. Power Vent Water Heaters

To distinguish between the two types of water heaters, we first need to understand how a Power Vent Water Heater (see also ‘Power Vent Water Heater: Why You Should Buy One‘) functions.

The underlying principle of a Power Vent Water Heater is no different from the idea behind a Direct Vent Heater. Both use air to create combustion in fuel and use the produced heat to heat water.

However, there are a few distinct differences between the two in the actual structure:

Source of air

outside air for heater

The Direct Vent Water Heater uses air outside your house to generate heat, whereas a Power Vent system uses air inside your home for the same effect.

The venting structure of a direct vent allows air outside the house to flow in and allow combustion. However, on the other hand, a Power vent system takes in air from inside the house, uses it for combustion, and then pumps the effluents out from the standard vertical vents.

There are also a few structural enhancements like exhaust fans placed in the venting system to ensure that all fuel effluents flow out of the house.

Direction of vents

The Direct Vent system pumps out the exhaust gases directly into the air via vertical pipes. These pipes are generally connected to your chimney or other exhaust systems.

However, such a system is not mandatory. The critical aspect is that effluents exit the heater using vertical vents. On the other hand, when using a power vent system, the gas effluents flow through a horizontal vent.

Since it is difficult for the hot gases to rise inside a horizontal pipe, a power vent system has a unique ‘blower’ attached to it. That device is responsible for pumping the hot air out of the system. The blower is essentially a fan that propels the gases out.

Material of vents

material for vents

The two systems of water heaters employ pipes made of different materials in their structure. The direct vent heater generally uses metal pipes in its skeleton, while the power vent heater generally uses PVC or other synthetic materials.

There is a relatively simple explanation as to why a direct vent heater uses metal pipes. Steel vents are prevalent in these systems because only strong metals can handle the high temperatures present in vertical vents.

Since power vent systems do not have vertical vents, they do not experience temperatures as high as those in vertical vents. Additionally, the fan present in the power vent system allows temperatures to go down.

Pros and Cons of using Direct Vent Water Heaters

Using Direct Vent Water Heaters instead of some other product has pros and cons both. These advantages and disadvantages are structural and functional in nature.

Let’s take a look at the pros of using this piece of technology:

Lower Operation Costs

If you carefully analyze a Direct vent water heater, you’ll find that the technology powering it is relatively novice.

In fact, its tech principles are very fundamental and basic. As a result, the operational costs of a Direct vent water heater are relatively low compared to parallel water heating technologies.

Most other water heaters will bring a steep increase to your electricity bill. However, the direct vent water heater runs without electricity; it will only save you money.

Lower Installation Costs

lower installation costs

As we have mentioned above, the tech aspects surrounding our direct vent water heater are relatively simple in structure. The entire vent system is significantly less complex than any electrical device.

Therefore, installation costs of the product are bound to stay low compared to those of other water heaters.

Direct Vent Water Heaters are essentially the most grass-root level of water heaters in the market today. They are perfect for tiny homes, need little maintenance, and are unbelievably easy to install.

Silent Operation

Except for the direct vent system, all other water heaters have a fan that pushes exhaust gases out of the heater vents. That fan is powered by electricity and is a complex gadget.

It only drives up operation costs and electricity costs. Most importantly, it drives up the sound produced by the heater.

Thanks to the absence of the fan in the direct vent water heater, it runs smoothly and silently without disturbing you or your neighbors. Most users who have been with the direct vent system have said that it casually “breathes” in and out without making a ruckus.

There are a few cons to the direct vent system:

Less Advanced

The Direct Vent Water Heater is not the most advanced piece of technology in the world. It is a simple, nonchalant, do-as-you-are-told mechanism that works without hindrance.

The rule of thumb when it comes to any technology is that when you compromise on complexity, you compromise on efficiency and output. Similarly, in this case, you would lose on the efficiency of a power vent system or an electric water heater while using a direct vent system.

While it would function adequately and heat all the water you want, you must remember that you can do better in terms of the machine.

Less Installation Flexibility

The Direct Vent system has a few obscure requirements that make it hard to install in absolutely any place. For instance, the vent system needs a complimentary exhaust system of some kind to function properly.

Every direct vent water heater works symbiotically with the house’s chimney to dispose of the gaseous effluents. Alternatively, only spaces where you can fit a vertical vent are viable for a direct vent fitting.

Not all houses have the facility of a chimney or a space for a vertical vent. Most urban homes do not have chimneys and rarely have any area outside the walls. Therefore, in such cases, the direct vent system becomes impractical. You can only use it in limited types of scenarios.

Does a direct vent water heater need a chimney?

direct vent pipe

Like we said before, the direct vent water heater is a relatively simple mechanical structure that needs a clear upwards path to clear all exhaust gases.

A chimney is the best form of vertical vent that this heater system can get. However, you can also make do with an artificial steel vent that goes up vertically along the walls of your house. The heater only needs a duct or pipe that can carry the gases upwards.

The direct vent water heater works on the simple principle that hot air rises and cool air sinks. You know that the direct vent system essentially inhales air from outside the house and uses it to generate heat.

Upon generating heat, the air inside the heater becomes hot and rises. This rising air needs to find a way out of the heater. That is when a vertical vent comes to our rescue and ejects the hot air out into the atmosphere.

Therefore, a direct vent heater does need a chimney. However, it can function adequately with any other vertical vent as well.

How much does a direct vent water heater cost?

You can get your hands on a top-notch direct vent water heater for approximately $700-1000. The price range can fluctuate a little according to the market, and buying additional features along with the heating system can raise costs.

However, you should be satisfied with your direct vent system if you bought it for $1000. It does not get better than that.

At the same time, a power vent water heater would have a cost bracket of approximately $1000-1500 and would also have a shorter life.

When do you need a direct vent water heater?

There is no specific demographic checklist that needs to be satisfied to require a direct vent heater.

Generally, a close-knit group of homes starts using the direct vent system together, making it a sub-culture in the locality. For example, a considerable number of households in North Colorado use that kind of water heater.

If you live in such a community, it is better to adopt a similar system of water heater vents because it becomes that much easier to maintain and repair. Your maintenance costs will be lower than usual in that case.


A direct vent water heater is a fundamental and straightforward system that most households can easily use. It uses basic principles of science and generates heat.

It also needs a chimney to let the heat escape from the vents. A direct vent system is a cost-efficient and low-maintenance option for your water heating needs.

Reference articles:

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Charlie Hardcastle


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