Tankless water heaters are the latest trend. You can get rid of those age-old massive water heating systems that take up a ton of room. Think about all the things you can do with the extra space that comes with tankless! Before you hit the stores, take a minute and ask yourself: do you need a condensing vs non condensing tankless water heater?
Not sure about the difference? This guide will provide the information you need on condensing vs non-condensing tankless water heaters. Then, you can decide which one’s best for your home or rental property.
Table of Contents
First, what Is a Tankless Water Heater?
As the name suggests, tankless water heaters lack the traditional storage tanks that come with tank-based models where the heated water is stored. They have gained massive popularity over their tank-based counterparts, which are both cumbersome and inefficient.
How Do They Work?
In tankless systems, the cold water passes through the water heater and is heated up on the run using a heat exchanger.
The heat exchanger warms the running cold water using combustion, and it keeps gaining heat as it passes through stainless steel pipes inside the heater.
Compared to traditional tank-based, these heaters are quite cost-effective. Instead of heating tons of water every time — half of which you will not use anytime soon — these models only heat the required amount of water at the moment, which helps you save a decent amount on energy bills.
As discussed, there are two different types. Additionally, it is important to know the difference between a condensing vs non condensing tankless water heater. Heating water produces steam as a by-product of combustion. The primary difference is based on how the heaters deal with steam, which has the potential to condense and corrode home appliances.
What Is a Condensing Tankless Water Heater?
A condensing tankless water heater is a completely closed system that recycles vapor to keep heating water and vents it only when water is no longer being heated up inside. The corrosive nature of the vapor and the heat are usually handled effectively by a pipe made of PVC.
Due to repeated usage and recycling, the vapor generated in this closed system is substantially cooler and does not require elaborate and expensive venting systems.
How Does It Work?
It is designed in a manner that allows the exhaust to be looped back into the system before it can be vented out. The gasses in the condensing system are not that hot, especially when compared to their temperature in a non-condensing system.
The system cools the gasses inside it and collects the water generated through condensation inside it as well. Since the condensate is acidic and can be hazardous, it is neutralized inside the system before being drained out of it.
Pros:
- They’re comparatively more efficient than their counterparts.
- These systems reuse the exhaust to heat water, helping you save on energy bills.
- Since the hot exhaust isn’t vented out, you don’t have to invest too much in durable, heat-resistant materials for the flue system.
- For the same reason as above, you can use cheap materials for the ventilation system without worrying about heat damage.
Cons:
- They might not fit into your existing fixtures.
- These systems are more prone to corrosion.
What Is a Non-Condensing Tankless Water Heater?
As opposed to a condensing tankless water heater, a non-condensing tankless water heater expels the steam generated, which then subsequently gets cooled down outside the unit. However, since the condensate is corrosive, extra precaution is required to ensure that the steam outlets are made of corrosion-resistant material.
How Does It Work?
A non-condensing tankless water heater has only one heat exchanger and is powered by gas. That’s why it’s considered a more basic version of a tankless water heater.
And again, unlike condensing tankless water heaters, these heaters do not loop the gas back into the heater — instead, it’s vented out directly. Subsequently, the temperatures of the steam can get searingly hot, sometimes even crossing 300 degrees Fahrenheit.
One of the main benefits of a non-condensing tankless water heater is its capability to utilize the existing ventilation system of a home. This makes it the most popular tankless water heater, with a larger share of heaters being non-condensing. When converting from legacy tank model water heaters, most people opt for this type of unit.
Pros:
- The upfront cost of non-condensing models is lower than condensing units.
- Since they have only one heat exchanger, they’re considerably smaller and more compact than their counterparts.
- Maintaining these water heaters is pretty simple. Seasonable professional servicing should be enough.
- They’re designed to fit into your existing fixtures. Switching to these heaters will not require any significant structural or plumbing line changes.
Cons:
- They’re slightly less efficient than other options on the market.
- The exhaust from these models is extremely hot, which might damage the vents unless you use durable materials
Condensing or Non Condensing Tankless Water Heaters: Which One Should You Choose?
So, which one should you choose to install in case you need a water heater? Well, there are a few things you might want to consider before making that choice. Let’s take a look:
1. Environmental Impact
The ecological factor is quickly gaining traction as more people are switching to a sustainable way of living. As opposed to conventional water heaters that burn fuel and release toxic emissions, the number of toxic emissions from tankless water heaters is negligible.
As such, both are considered eco-friendly options for water heaters. However, condensing water heaters have the lowest carbon footprint compared to almost any other water heater type available on the market.
If you’re very particular about the carbon footprint of your appliances, the condensing tankless water heater should be your go-to.
2. Savings
The steam recycling mechanism of condensing tankless water heaters makes them a better choice in terms of saving money. Since the by-product of the combustion is recycled and is used continually to heat the water, it requires far less energy, which subsequently gets you a little rebate on your energy bills.
Also, the condensate can be channeled back into your water pipes depending on how the connection is built, helping you save on water bills as well.
3. Durability
The lifespan of either condensing vs non condensing tankless water heater types depends on the build quality as well as the maintenance of the units. Both types have internal components that are liable to damage and wear and tear over the course of their lifespan.
For example, non-condensing tankless water heaters have searing hot steam passing across their exhaust pipelines as well as ventilation systems. This has the potential to cause leaks and weaken the materials over time.
On the other hand, the condensing pipes inside condensing tankless water heaters repeatedly handle corrosive emissions throughout usage. They must be constructed with sturdy and corrosion-resistant materials that are high-grade.
4. Pricing
Simply put, non-condensing tankless water heaters are cheaper and cost significantly less upfront to purchase and install. On the other hand, the extra heat exchangers and complex steam looping system of a condensing type of unit make it a more expensive option, both to purchase and maintain.
In the long run, the utility savings offered by condensing water heaters may balance the initial higher investment. But, if you’re on a tight budget, a non-condensing water heater may just be the option to go with.
5. Efficiency Quotient
In general, water heaters without a tank are significantly more efficient than electric models. So, if you’re upgrading from one, both variants will have much higher efficiency levels.
That said, there’s a small difference between the models. While non-condensing tankless water heaters are considered 80% efficient, condensing types boast 90% efficiency. In pure usage terms, you can’t go wrong with either type.
How to Select the Size of a Tankless Water Heater
One of the main drawbacks of a tankless water heater is that it heats water on the go without heating the entire water reservoir. While this is usually enough for a personal shower, it can get tricky when the entire family is lining up.
Knowing the capacity requirement of your family is a great way to ensure everyone gets their quota of hot water without having to wait for it.
Of course, determining how much hot water a family needs means taking into account several variables. If you standardize the temperature of the water and gallons-per-minute measurement of your water requirement, you can arrive at indicative numbers.
Gas-based tankless water heaters are generally labeled in GPM numbers, while electric tankless heaters are sized per kW numbers. It’s estimated that for a family of four, you will need a gas-based tankless heater within the size range of 8-10 GPM, while the corresponding size of an electric one would be between 20-28 kW.
Bottom Line
Choosing between a condensing vs non condensing tankless water heater depends on several factors. In this article, we have given you an extensive list of all the factors that differentiate the two units. All you have to do is align your requirements with these factors, and you will find your new water heater match.
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