What are the advantages of using a vertical heat exchanger in a boiler blowdown heat recovery system

April 13, 2017 by Aaron Rhoade

When developing a P & ID and/or floor plan for a boiler room installation, horizontal floor space is usually given a lot of thought and attention. Vertically designed boiler equipment allows for more efficient spacing in your boiler room and is also much easier to incorporate later on if  a piece of equipment is being added to a preexisting boiler room.

Madden Manufacturing’s HV series heat recovery systems are designed to operate with a small footprint. The unit itself stands on a 24” X 24” pad and other than where you choose to install the inlet manifold, the rest of the unit is does not take up much more than 2 square feet the whole way up.

Floor space can turn into an expensive commodity once the boiler room fills up. It is usually much less costly to install up than it is side to side in a room; but this isn’t the only advantage to having a vertical blowdown heat recovery system, and specifically, a vertical heat exchanger.

Coils are self-draining

The Madden vertical boiler blowdown heat recovery system design allows for the heat exchanger to be a coil and shell type heat exchanger with a self-draining coil. Hot, dirty surface blowdown from the boiler can be hard on piping in your system, the vertical design ensures that the boiler’s continuous blowdown will continuously flush all the way through your heat recovery system.

This significantly cuts back on maintenance requirements and improves the service life of our product.

No scale build up

The heat exchanger in Madden’s HV series heat recovery systems also avoid scale build up. Because the makeup water passing through the heat exchanger is never stagnant and always replenished, the shell side stays cool enough that minerals can’t develop, which causes the scale.

Once again, this will significantly cut back on maintenance required and increases the heat transfer efficiency and service life of our boiler blowdown heat recovery systems.

Choice between Copper and 304 SS coils: Added heat recovery, or added service life

A shell and coil heat exchanger is a simple and rugged design, and the vertical aspect of this design allows Madden Manufacturing to roll their own coils. Madden HV series heat recovery systems offer both Copper and 304 stainless steel coils.

Copper’s main advantage is better heat transfer. More BTU’s are picked up by the makeup water from the hot boiler blowdown through a copper coil than a stainless steel coil. This means money saved in your system. The more BTU’s that can be added to the makeup water, from the boiler’s continuous surface blowdown, the less fuel the boiler has to use to ultimately produce steam.

Vertical heat exchanger coil being assembled

304 stainless steel’s main advantage is longevity. Though a vertical system is designed to have long service lives and little required maintenance, inevitably coils do wear out. Stainless steel’s durability and strength helps the coil weather the constant stress of handling hot dirty surface blowdown from the boiler while externally being cooled by makeup water.

Full System provided in one unit, not pieces

A handful of competitive products on the market offer a flash tank vessel for the continuous blowdown and then the heat exchanger as separate pieces. Madden Manufacturing offers standalone boiler blowdown flash tanks and standalone coil type heat exchangers, but we also designed a one piece, full system for convenience.

Less piping and planning is needed with a Madden heat recovery system since it includes the flash tank and heat exchanger together, utilizing a float valve to allow the hot boiler blowdown to pass through the system mechanically. No electrical wiring needed for the essentials of our heat recovery systems’ operation.


If you are not currently recovering heat from your boiler’s continuous surface blowdown and are looking to do so, a vertical, one piece heat recovery design will save you time and energy in planning this addition as well as literally saving you space. Don’t miss out on the potential savings due to the hassle of figuring out how and where you can install a heat recovery system. The Madden’s vertical, one piece design makes adding a heat recovery system in your boiler room much easier than our competitors’ products.

And if you are planning a new boiler room entirely, enjoy the benefits of added floor space by using our one piece, vertical design.

There are hundreds of thousands of BTU’s leaving boilers every hour through continuous surface blowdown. We believe that recovering those otherwise lost BTU’s in your makeup water to save on fuel costs, is well worth the initial cost and time spent planning for a heat recovery system. And the Madden HV series heat recovery systems are about as easy as it can get when it comes to installing large boiler type equipment in a boiler room.

If you want help planning and/or pricing on your potential heat recovery system addition, see our sales rep page to find a local Madden distributor near you. And always feel free to give us a call (880-369-6233) or email (info@maddenep.com) about anything you may need.

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