With their recent rise in popularity, you may want to know, what is an indirect water heater?Indirect water heaters have been around for a while, but are becoming all the rage in the water heater industry.
This rise in popularity is partly due to increasing awareness of climate change and how we contribute to it by burning fossil fuels. Moreover, indirect heaters are cheap and, according to the Department of Energy, one of the cheapest means to get hot water.
Indirect water heaters work passively, which means they use another heat source instead of generating their own. These may not be the best choice for every household, but if the circumstances are right, indirect heaters may be your best bet at saving costs and the planet!
How Does an Indirect Water Heater Work?
Indirect water heaters do not have a burner or electric filament to heat water. Instead, they contain a heat exchanger coil containing a liquid. An external burner, such as your home’s space heater, heats this liquid.
The heat exchanger coil wraps around a storage tank in an indirect water heater. The heated liquid within the coil warms the water within the storage tank for regular use.
The heater’s close relationship with your home’s boiler means that it needs to be placed close to the boiler. You’ll also need a plumber to make the necessary connections between the heater and the boiler.
The heating coil is generally just a couple of additional pipes that your plumber will connect to the space heater and your indirect water heater.
Types of Indirect Water Heaters
There are three different types of indirect water heaters depending on how the water flows through them.
Heaters with storage tanks
Heaters without storage tanks
Hybrid tanks/ tankless systems
These are similar to conventional water heaters but heat the water in their storage tank through an external burner.
This is the cheapest type of indirect water heater. Instead of using a storage tank, it attaches the heat exchanger coil directly to the boiler and the water supply.
These use a hybrid system to supply water at two different temperatures. Storage tank supplies water at one temperature while the same water may be recirculated through the tankless system for an even higher temperature.
They are excellent in places where large amounts of water are required infrequently.
These are suitable for places where there is a constant demand for hot water in smaller volumes.
Suitable for bigger buildings that require water at different temperatures.
They generally take up a lot more space around the boiler.
This type of heater takes much less space in comparison to other heaters.
These take up the most amount of space.
Indirect Water Heaters vs Direct Water Heaters
Despite indirect water heaters making a wave in the market, direct water heaters remain the more common type of water heaters used in modern homes. Direct water heaters employ their integral heating system, which is dedicated to heating water. Thus, they burn more fuel and are less efficient than indirect heaters. On the plus side, you don’t have to install them next to a boiler for them to work.
However, there are plenty of benefits that indirect water heaters have over direct water heaters.
Category
Indirect Water Heaters
Direct Water Heaters
Pros
Energy Efficient.
Last longer since they aren’t as complex as direct water heaters.
Cost-effective.
Easy to install as they don’t need additional vents or chimneys.
Can be installed anywhere.
These aren’t dependent on boilers or space heaters and can work even if you don’t have central heating.
Cons
Need a boiler to work.
Can’t be installed anywhere except next to a space heater.
Not as energy efficient as indirect heaters since they have an independent burner only for heating water.
More complex due to the presence of a burner and may develop problems sooner than indirect heaters.
Expensive.
Should You Consider Shifting to an Indirect Water Heater?
Indirect water heaters are not only great for the environment but are an excellent way to save money and make your water heating system more efficient. Plus, they’re more reliable because of their simple design and will usually last longer than direct water heaters.
However, there are several factors that you must keep in mind before installing an indirect water heater. Remember, these heaters do not work without a boiler or a space heater installed in your house.
Thus, if you don’t have central heating, installing an indirect heater will not be possible. Moreover, you can’t place the water heater in the attic or any other location since it needs to be placed next to the boiler.
Another factor to consider is the condition of your boiler if you do have one installed. If it has been lying in the basement for over a decade with minimal to no maintenance, it is bound to lose some of its efficiency.
Installing an indirect water heater with an inefficient boiler won’t always give you optimum results. Nonetheless, it is still far more efficient than using an entirely separate appliance for getting hot water.
Frequently Asked Questions
Can I install an indirect water heater on my own?
While nothing is impossible with a little bit of research through Google or AI assistance, some tasks are better left to the professionals. Installing an indirect heater with your boiler requires specific optimization that will be better done by a plumber.
If both pieces of equipment are not optimized with each other, this may lead to inefficiency, defeating the purpose of the indirect heater in the first place.
What size of an indirect water heater do I need for my home?
Sizing your indirect water heater depends on your hot water requirements. Buying a heater that’s too big will cause inefficiencies, overheat the water, or cause your boiler to do extra work. Similarly installing an indirect water heater that’s too small will lead to not enough hot water available when you need it.
Plus, it’s always smarter to use an indirect water heater with a large storage tank if you have peak hours when the usage of hot water is high.
You can calculate your exact heater output requirements by using the water temperature you want in your output, the water temperature from the supply and the flow rate of water. You can then use these values in this equation: –
Heat output(BTU/h) = Temperature rise(°F) x Flow rate(gpm) x Specific heat(BTU/gal°F)
What costs am I looking at if I want to install an indirect water heater?
The cost of installing an indirect water heater depends on several factors. The main cost is the boiler, but if you have one installed, then you need to consider the cost of additional pipes and fittings. Generally speaking, you can expect anything from $400 to $1800.
The Verdict
Indirect water heaters are a great investment that contributes positively towards the environment and your budget. However, having central heating is key for these to work.
If you’re thinking of making the shift to indirect water heating, ensure you have a boiler in the basement. To that end, we hope that you now have the answer to the question, “What is an indirect water heater?”
Hi everyone! My name is Jason, and I am the founder of HeaterWise.com. Having run my own business as a Heating Engineer for 21 years, I have picked up a few things along the way.
I wanted to create Heater Wise as a place where anyone could come, from far and wide, to find the information that they need.
I hope you will join us here at Heater Wise, to get started on your own journey, to expand your knowledge, and make the best heating choices for you and your family.
