Nobody wants to inhale toxic fumes while the gas water heater is running. Of the many hot water heater vents to help the gas escape, deciding on a direct vent vs power vent water heater can be tricky, if not challenging.
If you are as confused as other homeowners, this article should give you a heads-up on the principal differences between these two gas water heater vent types.
Here is a rundown of their essential differences. Please continue reading to learn more about these attributes.
| Direct Vent | Power Vent | |
| Who uses them | Old homes | New homes |
| Ventilation elements | Vent pipes | Power-driven blowers or fans |
| Venting material | Metal | PVC |
| Water heater placement | Limited to maintaining close proximity to exhaust vents | Can be installed anywhere |
| Venting direction | Mostly vertical | Horizontal |
| Installation cost | Low | High |
| Pros | – Less expensive to install and operate
– Silent operation |
– Versatile placement
– More leak-resistant |
| Cons | – Inflexible | – Noisy operation
– Costly installation, maintenance, and operation |
Table of Contents
A Primer on Water Heater Vents
A gas-fed heater requires propane or natural gas to burn and raise the water temperature. Unfortunately, the process produces combustion byproducts. Venting requirements underscore the threat of these gases, such as CO poisoning or impaired thinking. This makes water heater ventilation more crucial than ever.
Hence, learning how to vent a gas-fed water heater is vital to ensuring safety. Equally important is deciding on the power vent vs direct vent issue.
Direct Vents
Most old homes feature a direct vent gas water heater because it is more economical and will continue working even in a power outage.
1. What is it
Direct venting options are nearly similar to a conventional chimney-linked standard vent. A direct vent channels hot air (i.e., combustion byproducts) outside the home without any additional mechanisms.
2. How does it work?
A direct vent installed to a 50 gallon (or any capacity) gas-fed water heater pulls outdoor air and channels it to the room housing the heater. Meanwhile, the system’s indoor component draws excess heat and combustion byproducts and vents them outdoors.
Exhaust gas movement occurs vertically along a vent pipe before moving horizontally towards the exhaust port and the outdoors. The system relies on the natural upward movement of warm air, which is lighter than cool air. As such, warm air can rise naturally along the vent pipes or chimney without the aid of external forces.
Because this system relies on atmospheric venting, you don’t have to do anything to get it to start working. Once the air warms up, it’ll automatically travel up through the pipes/chimney by itself.
- Hassle-free and practical installation
- Economical maintenance
- Fully manual operation
- Noiseless operation
- Ventilation issues (i.e., incomplete combustion when you vent gas water heater in basement)
- Chimney/vent requirement
Power Vents
Most modern homes use a power vent gas water heater to address a direct vent’s placement limitations. It is a versatile system that works like a direct vent, except it has an extra element to evacuate exhaust gases.
1. What is it
A water heater power vent kit has a fan or blower to facilitate hot air movement from the home interior to the outside environment.
In the ongoing power vent water heater vs direct vent debate, the former edges the latter in placement versatility. A power vent does not need direct access to chimneys or vents, and it’s able to evacuate combustion through horizontal pipes as well.
Power vents are an excellent choice for homeowners who want a high efficiency water heating and venting system.
2. How does it work?
A power vent’s definition implies positional flexibility. Ventilation installers can set up this system horizontally and never worry about exhaust fumes back-drafting to the heater room because the fan or blower ensures hot air’s forward movement.
Unlike direct vents that pull air from the outdoors, power vents draw hot exhaust gases indoors and channel them outside. This action prevents any unwanted buildup of carbon monoxide and other toxic gasses inside the home—a feature that direct vent systems aren’t very good at.
To use the power venting system, all you have to do is switch it on, which will get the blower starting.
- Versatile installation
- Safer operation
- A potential source of noise pollution
- Electrical requirement
- Costly installation, operation, and maintenance
Principal Differences between Direct and Power Vents
Here is a list of the key differences between a power and a direct vent system.
- Combustion air source – Power vents draw exhaust gases from indoors, while direct vents pull combustion byproducts from the outdoors.
- Venting direction – Direct vents rely on a bottom-up hot air movement—a natural law of physics, while power vents use blowers/fans to evacuate exhaust gasses horizontally.
- Venting pipe material – Direct vents almost always feature metal ventilation ducts to accommodate high-temperature exhaust fumes. Meanwhile, most power vent pipes have PVC or similar materials.
Price Differential between Direct and Power Vents
Power venting systems are 50 to 75% pricier than direct vents. It’s the additional parts, such as the blower/fan, and complicated setup that make power vent water heaters so expensive.
Moreover, ongoing operational expenses, including electricity to power the unit, can make this venting system less budget-friendly.
If the price differential seems unreasonable, you can replace a power vent water heater with a direct vent system, provided that you’re fine with less efficient combustion venting.
Which is Better: Power or Direct Vent?
Choosing between a direct vent and a power vent system depends on your priorities and the existing water heater setup.
Is a power vent water heater worth it? Yes, this system is worth the money if you don’t have an existing vent or chimney, or your water heater’s location makes it impossible to install a direct vent. It’s also beneficial if you’re concerned about backdrafts, which can increase the risks of carbon monoxide buildup.
Meanwhile, direct vents are better for households with existing exhaust vents (or chimneys), prefer simple setups, and favor affordable options.
Other Water Heater Venting Types
Power and direct vents are not the only ventilation systems for water heaters. You can also choose a standard atmospheric venting system. This technology is like a direct vent, except hot air only moves vertically through the chimney.
Tips for Ventilation
Ventilating your water heater is essential to ensuring safe operation by preventing the unwanted accumulation of harmful gases indoors. Here are some tips to guarantee more efficient and safe water heater ventilation.
- Hire a professional to install the water heater vent and prevent back-drafting issues.
- Check your local building code for regulations related to water heater venting.
- Let a professional clean, maintain, and service your water heater annually to ensure a properly functioning ventilation system.
- Ensure a match between the water heater storage tank’s draft diverter diameter and the ventilation duct’s cross-section.
- If you live in earthquake-prone areas (i.e., California), fasten each vent section with at least three screws.
- Water heater vent installers must ensure the ducts are straight, whether vertically, sloping, or horizontally.
- Ensure the correct placement of a gas water heater draft hood to guarantee safer and more efficient combustion byproducts evacuation.
FAQs
Do electric water heaters require ventilation?
First-time water heater owners always ask us, does electric water heater need to be vented? Although such a water heater also produces heat, electric devices do not create combustion byproducts. Hence, ventilation is not necessary for electric water heaters.
Which is more cost-effective: power vent or direct vent?
Direct vents are more cost-effective than power vents because they do not require electricity to facilitate hot air movement along the ventilation ducts and out the vent. They are also cheaper to buy, install, operate, and maintain.
Conclusion
Deciding on the direct vent vs power vent water heater issue can be both straightforward and confusing at the same time. Defining these vent systems is easy – the former relies on natural upward hot air movement, while the latter depends on blower-induced mechanical power.
Direct vents are suitable for budget-conscious families and households without ventilation issues. On the other hand, power vents are ideal for homes with limited space, requiring families to position the exhaust vent farther from the water heater.
As the founder of Usawaterquality, I have been working to deliver quality advice on utilizing water components for numerous households. Here, we believe that water quality is the most critical part of health care, so the investment and attention for the water system will never go to waste.