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4 DIY Heat Exchanger Plans You Can Make Today (With Pictures)

manufacture of a new heat exchanger with a carbon steel tube bundle

Heat exchangers are used for both heating and cooling. They are often used for ventilation in a home, though they have other uses as well. Usually, these heat exchangers are utilized in survival situations, but they can also be used in practical situations. For instance, some people use basic heat exchangers to heat their garage.

With that said, DIY plans for heat exchangers are few and far between. These are not usual DIY projects, after all.

However, we have included a few DIY heat exchanger plans in this article, which should help you make your own DIY heat exchanger.

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The 4 DIY Heat Exchanger Plans

1. Practical DIY Survival Heat Exchanger

Materials: Gallon drum, steel pipes, aluminum flex pipes, exhaust fan
Difficulty: Medium

This DIY plan is made with some basic materials that you can find at most hardware stores. The only material that you’ll have to really look for is the exhaust fan. You’ll need to co-opt a fan from some source for this purpose or purchase one on eBay.

This plan involves a lot of welding and leaves you with a heat exchanger for heating a garage. Of course, you could likely use it for other purposes as well.

While this is a DIY project, that doesn’t necessarily mean that it is terribly inexpensive. If you have to purchase all the pipes and drums, then you’ll probably end up spending quite a bit of money. For this reason, we don’t suggest that you go into this plan believing that it’s practically free.

You can also add a drip-fed waste oil system to the outdoor stove part of the heat exchanger. This will increase the amount of heat produced as is explained in the plan.

2. DIY Woodstove Heat Exchanger

Tools: MIG Welder, Bandsaw, Chopsaw, Bench Grinder, Angle Grinder, Rotary Tool, Tin Snips, Drill Bits
Difficulty: Medium

This heat exchanger is designed to work on a woodstove and helps you more efficiently transfer heat into your home. There are many steps to this DIY plan, and they all have to be pretty exact. Therefore, we typically only recommend it for those with some experience. Plus, you’ll also need quite a few tools that the average person doesn’t have just sitting around.

There is also some welding going on. If you haven’t welded before, you may have some trouble with this project.

In all, this is easily one of the more complicated plans we’ve seen, largely because of all the steps. However, the steps themselves aren’t terribly complicated—there are just so many of them!

3. DIY Heat Exchangers on a Solar Heater

Materials: Wrench, PEX Expansion Tool
Difficulty: Medium

This DIY plan involves adding heat exchangers onto a solar heater, which is often used to heat a garage or other building without a proper heating system. This plan is designed specifically for this purpose, so it isn’t terribly versatile.

However, if you’re interested in heating your garage, you could use this method to build a solar heater and then add heat exchangers to it. It does a pretty good job of heating your home in warmer areas, which may make it a good option for garages and similar outbuildings.

Keep in mind: this plan also involves quite a bit of welding. It is also in a video format, so it may make it a bit harder to accomplish (or easier, depending on your preferences).

4. DIY Grey Water Heat Exchanger

Materials: 5-gallon bucket gray water unit
Difficulty: Hard

While this may not sound all that luxurious, this DIY plan helps you retrieve and use the heat found in greywater. For instance, this unit will utilize the heat produced by shower water and similar hot water. Therefore, instead of it simply going down the drain, you can utilize this water to heat a room, potentially allowing a high percentage of the heat from being recovered.

However, this plan is quite difficult. You’ll need to redirect your pipes to ensure that you can capture this heated water into a bucket, then build the heat exchanger inside this barrel. In the end, it is quite a lot of work to put in.

With that said, if you’re producing a lot of hot water, it may be worth it. This plan is not going to be practical for everyone, though.

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Can You Cool with a Heat Exchanger?

Not typically. Often, heat exchangers work by taking heat from something really hot (like a fire or hot water) and transferring that heat to a different area. In this way, you can use a fire to heat your home, for instance. Or, you can reuse the hot water wasted after your shower.

However, while you could technically cool in this manner, it would be challenging. You would have to have something cool that is transferring the cool air into the space that you want to cool down. For instance, you may be able to use ice to cool down a room a little, but this is not practical (as you’d have to continuously fill it up with ice).

You can craft water chillers, which are a bit more common. However, these have a different function and use than a heat exchanger.

Which Heat Exchanger Design is the Most Efficient?

There are many heat exchanger ideas out there, which is exactly why we can’t point out one as the most efficient. It largely depends on what you’re trying to accomplish, as different heat exchangers all work differently. Some are designed to heat pool water, for instance, while others heat garages.

Heat exchangers are so varied in purpose that they can’t exactly be compared to each other in this manner.

With that said, a plate exchanger is the most efficient design. It allows for the most efficient flow from both sides and has a wide surface area. However, this design is not useful in all areas. Therefore, you’ll often need to use a different design for practical purposes.

How Much Does It Cost to Make a Heat Exchanger?

To replace a heat exchanger with a commercial option, you’re usually looking at around $2,000. However, making one is often cheaper, at closer to around $300. Of course, it depends on the exact metrics and what materials you already have on hand.

If you are able to recycle materials you have, you’ll often spend less money. Buying everything from a hardware store can add up fast, though.

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Heat exchangers are necessary for the production of heat. Without them, heating our homes would be difficult. With that said, you can use heat exchangers to make use of many different heat sources, ranging from the sun to hot water to fires.

We listed many different plans above that we hope to fuel your inspiration. Because everyone’s situation is different, it is hard to follow a plan perfectly and have it work. Usually, you’ll have to adapt the plan to your situation as many plans don’t drop easily into new locations.

Featured Image Credit: shinobi, Shutterstock

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