Over the last decade or so, outdoor furnaces, which are often referred to as outdoor wood boilers, have become quite popular as a viable and often inexpensive way to heat the home or business. These units, which are located outside the main building, heat water that is then moved inside a series of tubes to provide heat. Central to this process is the water line, the essential channel that carries this warmed water from the furnace to the habitable area. And while you can have a great heat exchanger and burn the best pellets imaginable, without a working water line, the entire heating system becomes negligible, marking its importance to any outside furnace layout.

And that leads us into the critical part of this water line: insulation. The furnace creates the heat, but the passage of hot water through the outdoor air is subject to wide temperature variations. So, both the attend of insulation  of insulation on this water line is vital. In this blog, we will be discussing the importance of why you should be using an insulated water line for your outdoor furnace, including benefits like freezing prevention, heat loss prevention, and overall system efficiency, which leads to longevity.

Why Insulation Matters: Preventing Freezing

Freezing is the most immediate and potentially devastating risk associated with a non-insulated water line connected to an outdoor furnace in cold climates. As temperatures plummet below freezing, the water within an unprotected line can turn to ice rapidly. This is not just an inconvenience; the volume of water increases dramatically when it freezes, creating gargantuan internal pressure inside the pipes. Without a buffer, this pressure has nowhere to vent, often with catastrophic results, such as ruptured or shattered water lines. Even if the pipe doesn't burst, the stress of freezing weakens the material, causing leaks and leading to failure of the system. Fixing or replacing a burst water line can be expensive and disruptive, leaving you without heat when you need it most.

However, utilizing insulated PEX pipe offers a significant advantage. This tool is specially designed with built-in insulation, so it forms an important thermal barrier that slows the ability for heat to flow from the water in the line to the cold outdoor air. And this is the main culprit, because it reduces quite a lot the possibility of the water freezing, hence the cold fire doesn't clog your system. While you can always take the necessary precautions to prevent pipes from freezing, using insulated PEX pipe is a forward-thinking step to help protect your lines at temperatures lower than standard, uninsulated lines would generally be able to handle.

Read more about How to Protect Your Outdoor Boiler System From Frozen PEX Pipe here.

Why Insulation Matters: Minimizing Heat Loss

These efficient heating machines operate by heating water to a predetermined temperature and then circulating the hot water through pipes into your home or building. But the path from the outside furnace to your home exposes the hot water to the outside environment. And if the water lines themselves are poorly in­su­lated, then much of this useful heat energy is wasted to the colder outer air as it makes its way to its destination.

This loss of heat has several negative effects. Firstly, it significantly limits the overall heating efficiency of your outdoor furnace setup. The supply water will be colder than desired, making your indoor heating elements work harder to achieve the desired temperature. Second, to make up for this lost heat, your outdoor furnace must burn more fuel (be it wood, pellets, etc.) to achieve the desired temperature of the water.

The result is more ferm­entation, which means greater fuel con­sumption, which means higher operating costs during the heating season. Utilizing insulated PEX pipe significantly combats this issue. Here, the PEX pipe has built-in insulation, which functions as a thermal blanket that limits heat transfer from warm water inside the pipes to cooler outside air. This insulation keeps the heat in the water line, so the water that arrives inside is as near as possible to the temperature it left the furnace. It delivers heat evenly and efficiently, reducing load on your inside heating unit, optimizing fuel consumption, and thereby reducing your heating costs.

Additional Benefits of Insulation

Beyond preventing freezing and minimizing heat loss, there are several other key benefits to insulating your outdoor furnace water line. Prevention is one of the major benefits of condensation. Condensation is when warm moisture in the air meets a cold surface. In some weather conditions, an insulated cold water line can create just such a cold surface. This causes moisture to accumulate around the pipes, which can lead to corrosion of metal components and water damage to surrounding structures or insulation on other sections of the system. When you insulate the water line as well (especially when using insulated PEX pipe), the surface temperature of the water line will be more consistent as well, reducing the temperature difference that causes condensation to form.

Also, the best System Longevity comes with insulation, and quite a bit of it (at least as much as the high-tension PEX, I suppose). It reduces the amount of stress due to expansion and contraction from freezing or temperature fluctuations by acting as a barrier against environmental conditions. Furthermore, stopping corrosion from condensation protects your pipes in the long run. This means fewer repairs and replacements, which equates to a longer life of your entire outdoor furnace system.

Lastly, a well-insulated water line, especially one using insulated PEX, enhances Safety. It is an effort that minimizes freeze and/or rust that weakens the pipes to leaking, in turn reducing the likelihood of boiling water escaping and scalding you, or providing water that your electrical appliances may be out of reach of. The well-maintained and protected system is a much safer system for you and your property.

Conclusion

An adequately insulated water line is indispensable for a functioning outdoor furnace. As we said, the benefits go well beyond just keeping a constant temperature. Well-insulated water line, especially using insulated PEX pipe, acts as a vital buffer against the forces of freezing temperatures, protecting you from the dangers of destructive property damage caused by system failure as a result of bursting pipes. Furthermore, it's imperative to minimize heat loss during the transport of heated water to your indoor spaces, directly impacting heating efficiency and fuel consumption.

Beyond these primary benefits, insulation, particularly the durable and efficient nature of insulated PEX, helps to extend the lifespan of your system by reducing condensation and the risk of corrosion. In conclusion, proper insulation for your outdoor furnace water line is not merely an option but a fundamental step to ensure your heating investment operates at its best, is efficient, durable, and safe. This preventative measure reaps rewards in lower operating costs, fewer repairs, and the steady, reliable warmth you demand from your outdoor furnace system.

FAQs

  • Can PEX be used outside if insulated?

Pre-insulated PEX pipe is a type of plumbing system for underground outdoor use.

  • Can you use PEX for a furnace?

1 in. x 300 ft. Non-Potable PEX Tubing for Heating Applications and Boiler Installation with Oxygen Barrier Approved for radiant floor heating applications. PEX Tubing w/ OX is the most common size for outdoor wood boiler installations.

  • Can you use PEX for an underground water line?

Yes. Because of its high temperature resistance, which makes it fit for hot and cold interior plumbing applications, PEX is also a very good underground water service piping.