PEX for Radiant Heat: “The Ultimate Guide for Underground Installations”

PEX for Radiant Heat: “The Ultimate Guide for Underground Installations”

Radiant heating systems are becoming very popular in houses because there are lots of advantages, like increased comfort and energy efficiency. One big reason for these systems is the PEX tubing because of its adaptability, toughness, and ease of installation. However, there are other limitations to radiant heating using PEX tubing. This blog article will go over the benefits and drawbacks of radiant heating in houses using PEX tubing.

Advantages of Using PEX

Due to its exceptional comfort and energy efficiency, the floor radiant heating system has steadily emerged as the go-to heating option for contemporary homes and businesses as science and technology have advanced and people's quality of life has improved. Because of their exceptional performance and numerous application opportunities, PEX pipes have become an essential part of this system. The advantages of PEX pipes in radiant floor heating systems will be thoroughly examined in this blog article.

1. Improved energy efficiency. 

Radiant heating circulates heat more uniformly and also evenly throughout the room by warming from the floor upward to the ceiling, in contrast to earlier forced air systems that might provide warmth from the top ceiling to downward. This method decreases the heat loss and reduces energy costs. Since PEX tubing has a low thermal conductivity and also stores heat much better than other materials, radiant heating systems consume less energy. For more details, check the article “Insulated PEX Pipe: Am I Losing Heat Underground?”.

2. Increased comfort. 

As a response to the temperature variations, it’s important to consider this when designing your system, particularly for the radiant systems. PEX-a is like the most flexible, and PEX-b and PEX-c are less flexible but nonetheless they have many benefits of their own (e.g., cheaper, chemical resistance). Read which type of PEX is good for your outdoor boiler HERE. 

3. The easy installation of PEX pipe. 

PEX can be actually installed using various methods like in-slab, staple-up, and also sandwich systems. Each of its methods has its own set of benefits, but overall, the PEX is much easier to install compared to the other radiant heating materials like the copper or steel, which is saving both time and money on installation costs. For more details, check the article “Proper Installation of PEX Pipe for Optimal Performance in Your Wood Boiler”.

4. PEX tubing is known for its durability. 

It is highly resistant to corrosion, a very common issue with materials like steel or copper. PEX tubing is also very flexible, allowing it to withstand both  freezing and thawing cycles without cracking or even breaking, which increases its longevity and also reliability. For more details, check the article “Choosing the Right Underground Pipe for Your Outdoor Furnace”. 

5. Uniform heat dissipation.

The radiant heating systems, especially the one utilizing the PEX pipes, would distribute the hot water at temperatures which do not exceed 60°C to warm the entire floor. This process would eventually then radiate the heat evenly around the room so that the end result is a very constant and comfortable place without the localized overheating and even cooling problems associated with the conventional heating systems.

6. PEX tubing is also highly efficient and environmentally friendly. 

It uses radiation to transfer heat without producing air convection, which prevents the spread of dust and microorganisms. This results in a lower energy consumption while maintaining the same indoor comfort levels as traditional systems. Furthermore, the PEX is a very sustainable material, aligning with the modern architecture’s focus on energy savings and in environmental protection. 

7. The flexibility of PEX  

It can be installed under various floor materials, such as wood floors, ceramic tiles, and carpets, providing versatility for different construction projects. This adaptability eventually makes the PEX a popular choice for a very wide range of applications. 

8. PEX systems operate on low-temperature hot water. 

Making them compatible with the modern high-efficiency boilers, the solar heating systems, and other advanced equipment. This integration actually improves the overall energy efficiency and also reduces the environmental impact. 

9. Quiet operation and low maintenance costs.

Make PEX systems an attractive option. PEX pipes are almost silent during the operation, making them much quieter than traditional heating systems. Their simple structure would also lead to even  fewer breakdowns, lower maintenance costs, and also more economical heating solution for the homeowners.

Choosing the Right PEX: Factors to consider 

A number of criteria are very important to consider whenever selecting the PEX (cross-linked polyethylene) piping for your system, particularly for the applications like in the outdoor heating, plumbing, or even in radiant heating. Below is a summary of the important factors:

Soil Conditions (for Outdoor Installations):

  • Corrosive Soil: You should think about utilizing PEX that is specially graded for underground use if you're putting PEX pipes underground in places with corrosive soils (such soils with a high acidity or salt content). For subterranean installation, the outer layer of PEX usually has an extra layer of protection to guard against chemical degradation and dirt and rock abrasion.

  • Rocks & Sharp Objects: To prevent damage, make sure the PEX you select has a enough protective layer if your soil is rocky or rough. You may also want to add a protective conduit around the pipe.

  • Temperature Extremes: Select PEX with higher temperature ratings (such as PEX-a, PEX-b) in regions with extremely high or extremely low soil temperatures. This is because these PEX can withstand a greater range of temperatures.

Climate:

  • Cold Climates: PEX is like the perfect for freeze resistant applications especially in cold climates since it is very well-known for its flexibility. PEX is also frequently chosen in cold climates because, unlike copper or PVC, it may expand if it freezes. If the PEX is exposed to sunlight, however, make sure it has a suitable UV-protective coating for long-term dependability because UV rays can deteriorate the material.

  • Hot Climates: UV damage is a greater worry in hot climates. To prevent direct sun exposure, PEX pipes used in exposed or outdoor settings should be buried underground or have an outside covering that blocks UV rays. Generally speaking, PEX-a and PEX-b provide more UV resistance than PEX-c.

Heating Needs (for Radiant Heat or Hydronic Systems):

  • Heating Load: The amount of the PEX pipe needed will actually depend upon the amount of heat it is required to provide. The diameter and the spacing of the PEX tubing will also affect how efficiently radiant floor heating provides the heat. For home radiant systems, ⅝-inch or ¾-inch PEX is usually used. PEX that has a larger diameter might be used for large commercial systems.

  • Pressure Rating: PEX is definitely available in a variety of pressure ratings, including in both 160 and 200 psi. In heating systems, you may want to ensure that the pressure rating of the PEX is the same as the pressure in your system. While it's always the best to refer to the very system requirements, most heating systems will actually not exceed 100 psi.

  • PEX expands and contracts: As a reaction to the temperature changes, it's very important to factor this in when you are planning your system, especially for the radiant systems. PEX-a is definitely the most flexible, and PEX-b and also PEX-c are less flexible but still they have advantages in their own right (e.g., lower cost, chemical resistance).

Type of PEX:

  • PEX-A: The most versatile variety, is perfect for uses such as radiant heating. Because it expands, it can be utilized in frigid temperatures. Additionally, after being bent, PEX-a has the best memory for reverting to its previous shape.

  • PEX-B: renowned for its increased chemical and pressure resistance. Additionally, it is easier to manage in systems where flexibility isn't as crucial because it is more rigid than PEX-a.

  • PEX-C: This type is less expensive and more stiff. It is often less flexible than PEX-a and performs worse in freezing temperatures, even though it can be utilized in heating systems.

Longevity and Durability:

  • UV Resistance: Protect the PEX pipes from UV deterioration by making sure they are UV-resistant or by burying them underground if they will be exposed to sunlight.

  • Chemical Resistance: PEX-b often provides superior chemical resistance and is more resilient to hostile environments.

PEX and Radiant Heat Systems: Design Considerations and Installation Best Practices

Whether a PEX radiant heat system is being designed and installed for snow melting, hydronic heating, or radiant floor heating, there are a number of important factors and best practices to take into account in order to guarantee the system's durability, effectiveness, and efficiency. This thorough guide will assist you in the process.

1. System Design Considerations:

Heat Load Calculation:

  • Establish Heating Requirements: To guarantee sufficient comfort, determine the space's heat load (the quantity of heat needed) before selecting your system. This will be affected by elements including the local climate, insulation, and room size.

  • Manual J calculation: The industry-standard method for figuring up the precise heating needs. It takes into consideration things like the air infiltration, window size, orientation, and also insulation.

  • Pipe Size and Spacing: Heat distribution is then influenced by the pipe diameter and also the spacing. Floors which are typically spaced to about 12 to 18 inches apart, although this will depend upon the heat load estimate. Closer spacing (e.g., 8-10 inches) might be very necessary for the smaller rooms or higher heating demands.

Choice of PEX Type:

  • PEX-A: Very flexible and easy to install, especially in coil rolls, making it perfect for radiant heating systems. It is the ideal option for freeze-resistant systems since it also has the finest memory for reshaping.

  • PEX-B: An excellent compromise between the stiffness and also the flexibility. Compared to the PEX-a, it is somewhat less flexible but much more resilient and even resistant to the chemicals.

  • PEX-C: A more rigid choice that is usually not the ideal for the radiant heat because of its higher installation difficulty and also decreased in flexibility.

Design of Loops and Zones:

  • Loop Length: It's very crucial to consider the length of each loop, which is the PEX tubing that moves the water. Excessive loop length might then result in uneven floor temperatures and the inadequate heat distribution. For like 1/2-inch PEX, the typical loop length is about 200–300 feet, while for the 5/8-inch or 3/4-inch PEX, it is 300–400 feet.

  • Zoning: You might want to establish distinct zones if your heating system is huge or has like several sections with varied temperature requirements. Zoning enhances system efficiency by enabling more accurate temperature management.

Temperature Control:

  • Manifolds: To distribute water to every loop, use a manifold. Additionally, it can actually serve as a control point for isolating zones and modifying flow rates.

  • Thermostats and Mixing Valves: Compared to the forced air systems, radiant heating systems typically employ the water temperatures that are between from 120 and 140°F. The water temperature entering the system is kept within the appropriate range by a mixing valve. Zone controllers or room thermostats aid in regulating the temperature in various spaces.

2. Installation Best Practices:

Preparation and Layout:

  • Insulation: To stop heat loss to the ground or flooring, the PEX tubing must be properly insulated underneath. Make use of foam panels or high-quality insulation board. This prevents the heat from being absorbed by the floor or soil below and instead directs it upward into the room.

  • Create a Layout: Give great thought to your PEX layout. To ensure uniform heat distribution, the tubing is usually arranged in a serpentine or snail design. PEX should not be placed next to walls because the perimeter frequently needs additional heat.

  • Expansion Gaps: As temperatures fluctuate, PEX expands and contracts. To accommodate this movement, leave expansion gaps where the PEX contacts walls or other fixed structures. By doing this, the tubing will be less likely to sustain damage or cause floor buckling.

Securing the PEX Tubing:

  • Staples vs. Tracks: Secure the PEX tubing with the proper fasteners. While the track systems are utilized in order to secure the tubing to stiff foam insulation (particularly in concrete slab floors), staples (plastic or metal) are typically used to attach the tubing to a wooden subfloor.

  • Consistency in Spacing: Make sure that the PEX is evenly spaced this is because the irregular spacing can result with an unequal distribution of heat. To keep the tubes at the right distance from one another, use the measurement tools or guides.

Testing the System:

  • Pressure Test: To make sure there are no leaks in the system, always perform a pressure test prior to covering the tubing or laying concrete. Typically, this is then accomplished by adding the water into the system, applying pressure, and also tracking the pressure drop over time.

  • Flushing: To get rid of any debris that might have gotten into the pipes during the installation, flush the system even after installation.

Pouring Concrete or Installing Floor:

  • For Concrete Slab Systems: Ensure that the PEX tubing is firmly positioned within the slab at the proper depth if you're installing it in a concrete floor. To guarantee the effective heat transfer, the tube is usually positioned 1-2 inches below the surface.

  • Regarding Underfloor or Radiant Panel Systems: Make sure that the system is securely fastened and that the floor covering (carpet, hardwood, tile, etc.) is much compatible with the radiant heat before utilizing radiant panels or PEX underneath pre-existing flooring.

3. Maintenance and Troubleshooting:

  • Air Venting: Over time, air can accumulate in the system, which can reduce efficiency. Ensure that your system is equipped with the air vents in order to prevent airlocks.

  • Annual System Checks: Perform the regular checks in order to ensure that the system is working as expected, including all the testing pressure and also the temperature settings.

  • Professional Servicing: While the radiant heating systems are relatively low-maintenance, it’s definitely always a good idea to have a professional to inspect the system periodically, especially the manifolds, mixing valves, and also thermostats.

4. Energy Efficiency:

  • Low Water Temperature: Low water temperatures maximize the efficiency of radiant heat systems. There is no need for overly hot temperatures because heat rises from the floor to offer a steady, comforting warmth.

  • Smart Controls: By automatically modifying the temperature according to your schedule, programmable thermostats or smart home integration can further maximize the effectiveness of your heating system.

5. Common Pitfalls to Avoid:

  • Excessively Long Loops: Excessive loop length can cause uneven heating, causing the regions furthest away from the manifold to not heat up adequately.

  • Inadequate Insulation: Considerable heat loss may result from improper insulation beneath the PEX tubing, particularly in concrete installations.

  • Inappropriate Pump Sizing: The circulator pump needs to be sized to satisfy the system's head and flow requirements. Poor circulation and ineffective heating can result from using a pump of the incorrect size.

Insulation for Underground Radiant Heat: Types and Importance

Importance of Insulation for Underground Radiant Heat:

Since it stops the heat loss to the surrounding ground, insulation is very essential to subterranean radiant heat systems. Significant heat loss would eventually occur beneath the system in the absence of adequate insulation, resulting in inefficiencies and also increased energy usage. Insulation will guarantee that the system will run at a maximum efficiency, delivering a constant warmth while lowering overall energy expenses by directing the heat toward the intended area. Furthermore, effective insulation can improve the system's efficiency by assisting in maintaining the heated area's optimum temperature, which eventually raises comfort levels, particularly in the colder areas.


Types of Insulation for Underground Radiant Heat:

  1. Rigid Foam (Extruded Polystyrene - XPS) is definitely among the most widely utilized kinds of insulation for the systems that employ radiant heating. In order to minimize the heat loss, it provides a high R-value. Because it is resistant to moisture, rigid foam is a long-lasting option for the subterranean applications, particularly in some locations where the groundwater may be a major issue. In concrete slab installations, its stiffness makes it very simple to lay underneath PEX tubing, giving the system a much stronger base.

  2. Foil-faced Insulation Usually has a reflective surface that reflects heat upward into the heated area, improving heat transfer. When combined with the radiant barriers in all walls or floors, this kind of insulation performs especially effectively. Because the foil-faced insulation is very reflective, it improves heat retention and eventually lowers heat loss to the ground, increasing total energy efficiency.

  3. Spray Foam Insulation is an additional choice for radiant heat systems, particularly when adaptability and a personalized fit are crucial. When applied, it fills in spaces and seals around PEX tubing. Spray foam can assist shield the system from moisture by acting as a vapor barrier and providing exceptional heat resistance. However, because of its application procedure, it needs to be installed by an expert.

  4. Fiberglass Insulation is occasionally utilized in every radiant heat systems, however its R-value is much lower than that of rigid foam or the spray foam. Although fiberglass is unfortunately reasonably priced and can occasionally be placed underneath the PEX tubing, it may become very ineffective if it was crushed or exposed to moisture. It's very crucial to make sure fiberglass insulation is put and also maintained correctly to prevent gaps or deterioration over time.


Benefits: Efficiency, Comfort, and Cost-Effectiveness of Radiant Heat with PEX

Efficiency:

In contrast to conventional heating techniques, radiant heat with PEX functions at lower water temperatures, making it extremely efficient. The system may provide constant warmth without the need for high-energy inputs since heat naturally rises from the floor. This implies that less fuel or electricity is used overall since less energy is required to keep a room at an acceptable temperature. Over time, this efficiency results in energy savings and less pressure on heating equipment.

Comfort:

The degree of comfort that the radiant heat with the PEX offers is actually one of its most notable advantages. Radiant heat evenly distributes warmth over the floor, in contrast to the forced-air systems, which may produce both hot and cold areas because of irregularity in airflow. Because of this uniform heat distribution, there are no unexpected temperature swings and also the entire space feels cozy. Because the heat is generated from the ground up, the entire room has a constant, comfortable atmosphere.

Cost-effectiveness:

PEX radiant heat systems are very reasonably priced. Compared to the conventional forced-air systems, which must continuously cycle both on and off to disperse hot air, they eventually use less energy to maintain the necessary temperatures. Radiant systems use less energy by heating the space effectively and also running at lower temperatures, which lowers utility costs. These savings eventually help the system to become more cost-effective, making it a wise investment with long-term financial gains.

Conclusion

PEX's versatility, robustness, and also efficiency make it a great option for the subterranean radiant heating systems. It actually uses lower water temperatures in order to save energy while providing a steady, even heat distribution that improves comfort. It is a much better choice than alternative materials because of its cost-effectiveness, ease of installation, and also resistance to freezing. PEX is a very popular option for professionals and individuals whose wish is to maximize their radiant heating systems because of its adaptability to the different system designs and conditions, which eventually guarantees dependable, long-term performance.

PEX's reputation as a leading option for the subterranean radiant heating systems which is further cemented by its adaptability in both residential and  the commercial applications. Its lifetime is guaranteed by its resistance to the scale and corrosion, and also its capacity to expand and contract without sustaining damage makes it more perfect for a range of temperature situations. Compared to the metal piping, PEX has fewer fittings and connections, which streamlines the installation and saves money on labor and time. PEX is still a very dependable and popular material for contemporary radiant heating systems because of its demonstrated track record of dependability, energy efficiency, and user-friendliness.

If you're looking for guidance in the radiant heating systems, the PEX installation, or even in optimizing your underground heating setup, contact us at OutdoorBoiler.com. Our technical support team is always ready to assist you with expert advice on the installation, maintenance, and also troubleshooting. We are very committed to ensuring your system operates efficiently and also reliably. When you need a professional help, we’re here to walk you through every step get in touch with us today for all your radiant heating needs.