The Difference Between Atmospheric and Power Vented Hot Water Tanks

Homeowners rarely think about their hot water tank until something goes terribly wrong. Usually, that just means they’ll be shocked with a blast of cold water in the shower when they were expecting warm water or a hot tap producing freezing water. But in the case of these Canadian homeowners, being unaware of their hot water tank’s venting type almost cost them their home and their lives.

In a small Canadian town, a homeowner was staring at the roof and decided it was time to get rid of the chimney. Their furnace didn’t use it, and they didn’t have a fireplace. She assumed it was from decades ago before the new furnace installation. Her real estate agent mistakenly told her it was capped, and she was OK to go ahead with sealing it.

Fast forward to the middle of the night, not long after. The carbon monoxide detector in the home warned of poisonous gases, evacuating the four family members, dogs and their tenant. After an investigation was complete, it was discovered that the chimney was the venting system for their atmospheric vented hot water tank.

Knowing the difference between an atmospheric and power vented hot water tank could save your life – literally. Read on to learn the critical differences between them, which system may be better for your home and how to identify what type of hot water tank you have.

Atmospheric Vented Hot Water Tanks

Atmospheric venting is a method in which exhaust from a water heater naturally rises from the appliance’s combustion chamber and goes up via a typical, chimney-style flue that expels the gas out on the roof. Unlike other ventilation methods, atmospheric venting does not need a motorized fan. Still, it requires installing an exhaust pipe that extends uninterrupted from the water heater to the roof. You’ll typically see a completely vertical or upward sloping metal duct that leads to the chimney.

If you check your current water heater and observe a metal pipe rising from the top, you very likely could have one of these systems. The atmospheric venting hot water tank was the first type of heater, and you’ll see them more frequently in older homes. This method heats the fuel, which then warms the water. The pressure of burning pushes excess gas higher and out your chimney or vent. Once the water has been heated, there has to be enough fuel in the tank to produce adequate pressure to propel these gases upward and out.

Pros of atmospheric vented hot water tanks

Due to its simple structure, the atmospheric venting method is often the least expensive route when installing a new hot water tank. It doesn’t need any electricity and will even run when the power goes out. You can use the hot tap, even when you can’t turn a light on!

Cons of atmospheric vented hot water tanks

Enough heat has to remain in the atmospheric venting tank for the gases to exit correctly. This suggests that a percentage of the fuel utilized does not heat water but instead rises with the fumes and escapes through the chimney. This wastes energy and money on your hydro bill. Worse, if something goes wrong and the gases do not rise as they should, the gases may expand and cause the water heater leaking carbon monoxide into the living space of your house. This has the potential to cause you to become unwell or a catastrophic explosion.

Power Vented Hot Water Tanks

Power vent water heaters feature built-in fans that force the exhaust gas out of the vent through a powered fan. They have rapidly become the norm for newly constructed houses. This is because power vent water heaters are practically impossible to backdraft due to their unique structure. That implies the likelihood of carbon monoxide problems produced by your water heater is considerably reduced when you use a power vented water heater compared to the atmospheric venting system.

Take a look at your hot water tank to see if an electric blower fan is installed at the top of the heater. You’ll often see vertical or horizontal vents with a longer line, making it more flexible for your space.

Pros of power vented hot water tanks

Calgary homeowners are opting for power vented hot water tanks because of the convenience. They can virtually be located anywhere near an electrical outlet in your home since they don’t require a vertical vent or chimney. They are also noted to be more energy-efficient since all the fuel is being utilized to heat the water, while the fan will push the harmful gases out of your home. You also don’t have to worry about the water heater leaking carbon monoxide due to improper ventilation.

Cons of power vented hot water tanks

Since the power vented hot water tanks require electricity, you also lose your hot tap capability if you lose power. It’s also a bit noisier than the atmospheric venting system since it requires a fan/blower to push the dangerous gases out of your home. Keep in mind that the noise isn’t very noticeable but should be noted if this is a cause for concern.

The heater’s location most commonly dictates the ideal venting technique, but you must also ensure that the venting method can withstand the heater’s power. Your house, health, and even life might be jeopardized if the water heater isn’t properly vented. This is why a qualified expert should install any water heater.

If you have questions about your hot water tank’s ventilation system, you noticed your water heater leaking or your hot water has suddenly stopped working, call the professionals at Plumbing and Heating Paramedics of Calgary. We’re available 24/7, whether it’s an emergency stop-in or scheduled check-up. Call us at (403) 879-7213 or contact us to book an appointment.

Before reading this article, did you know what type of hot water tank venting system you had? Do you have an atmospheric vented hot water tank or power vented? Do you notice the noise if you have a power vented hot water tank? Let our readers know your experience to help them decide when they’re in the market for a new hot water tank!