hot water boiler piping
Boiler Water Loops - In boiler hydronic loops there are different ways to arrangement the piping depending on the budget at installation time and how efficient and balanced you want the hydronic piping system to be when the job is complete. Some piping arrangements require more pipe upon initial installation. However, they are easier to balance and provide even heat throughout all the radiators or baseboards.

Boiler Water Loops | Hydronic Piping Systems

It is important to consult with a plumbing and heating professional. Consultation should be done before deciding which type of hydronic piping arrangement you want. The type of piping loop you will use for your hydronic loop. They can show you the distinct advantages and disadvantages along with cost differences of various hydronic piping arrangements. The piping system you need for the structure where you intend on installing this system. The type of loop can oftentimes be just as important as properly sizing the boiler pipe and system as a whole. It can make all the difference in the world in comfort and efficiency. Consulting a professional will ensure design is done properly from the start.

Boiler Water Loops – One Pipe Series Hydronic Loop

One Pipe Series Loop

The One Pipe Series Loop uses less pipe than any other hydronic piping arrangement. Therefore it is less expensive to install the piping. However, you need bigger radiators or longer baseboards. However, only at the end of the loop because this part of the loop will have less heat. The radiators or baseboards at the beginning of the loop use most of the heat. Consequently, this is the reason for the larger radiators and baseboards at the end of the loop. There is also a larger temperature drop in this type of loop. A temperature drop between the supply and the return versus other types of hydronic piping arrangements. The near boiler piping may need to be modified to prevent large delta T between supply and return.

We have many other related articles. Please use the search feature or menu to the right to help you find other related articles.

Boiler Water Loops - Monoflow Hydronic Loop and Monoflow Tees

Mono Flow Tee, Hydronic Loops

The monoflow hydronic loop is similar to the one pipe series. The exception is the main loop uses monoflow tees to divert the water. It diverts water to the radiators or baseboards using special Tee’s. The main hydronic loop maintains a constant flow on a call for heat. Using this system, the water temperatures for each zone are more even throughout the hydronic loop. More even than the one pipe series hydronic loop. The monoflow tee is a special tee. The monoflow tee is installed at the supply and the return. The supply and return for each radiator or baseboard.

This loop system is easy to zone but needs more piping and special monoflow tees for each separate circuit. Additionally, if not installed properly flow problems will occur in radiators and/or baseboards. It is really important if you have a monoflow system to consult a professional before making changes. If you want to modify it in any way for an addition or other work. Always consult a plumbing and heating HVAC specialist for any changes to a monoflow loop.

monoflow hydronic pipe system

Boiler Water Loops – Two Pipe Direct Return Hydronic Loop

two pipe direct return

The Two Pipe Direct Return Loop utilizes more pipe than the one pipe series loop. However, all radiators and baseboards receive the same temperature of water, therefore it is more even heat. More even heat than in all the radiators and/or baseboards than the one pipe series loop. Another advantage of two pipe direct return loop over the one pipe series loop is that it can be zoned. Zoning gives you more control over where and when you want heat. This can save you money on the cost of heating. As with many hydronic loop systems the two pipe direct return needs balancing valves. The near boiler piping may need to be modified to prevent large delta T between supply and return.

Spirovent Jr air eliminator model VJR100 features a patented Spirotube coalescing component, which "filters out" the air from a hydronic or radiant heating system' fluid, allowing for improved performance and extending the lifespan of the heating system's components.Spirovent Jr air eliminator features an easy to install, in-line design, making it ideal for a large variety of residential and light commercial uses with pipe sizes ranging from 3/4" to 1-1/4".Spirovent Jr model VJR100 is also equipped with a 1/2" threaded tapping, which allows for easy connection of an expansion tank.Installation manual included.VJR100. Click on the image for pricing and availability.

Taco Flo-Cheks are used in a forced hot water heating system to prevent "gravity" circulation during periods when the boiler is hot but the space heating zone is not wanted. This makes it possible for the use of the heating boiler to maintain domestic hot water year round. In systems with multiple circulator zones, Flo-Cheks allow heat to flow only into the zones that are calling for heat. Also, the thumb screw can be manually opened for gravity feed applications if the main circulator stops operating. Click on the image to see pricing and availability.

Amtrol ST-12 THERM-X-TROL Expansion Tank, 4.4 Gallon (141N43) What Is Thermal Expansion? With modern plumbing codes mandating backflow prevention, thermal expansion can cause pressure buildup in domestic water systems. When demand is put upon a potable water system, hot water is drawn from the water heater. Cold water from the supply line enters the water heater to replenish it. The colder water is heated to replace the hot water used. With the installation of a backflow preventer, check valve or pressure reducing valve on the supply line, the water heater and the system piping form a closed plumbing system under pressure. As the water is heated, thermal expansion occurs. Pressure increases until the relief valve opens and the expanded water "spills" from the water heater. This "spillage" results in wasted BTU's and a potential safety hazard for the homeowner. Click on the image for pricing and availability.

This Apollo Valve 10-400 series safety relief valve has a bronze body, a 30 pounds per square inch (psi) relief pressure, a 3/4" male National Pipe Thread (NPT) inlet connection, and a 3/4" female NPT outlet. The valve's body and nozzle are bronze for resistance to corrosion, the seat is silicone for resistance to high temperatures, and the spring is stainless steel for resistance to corrosion. The valve can be used in operating temperatures up to 250 degrees F. This safety valve is American Society of Mechanical Engineers (ASME) safety rated for Section IV hot water heating boilers and hydronic heating systems. Click on image for pricing and availability.

Boiler Water Loops – Two Pipe Reverse Return Hydronic Loop

two pipe reverse return hydronic loop

The Two Pipe Reverse Return Hydronic Loop uses more pipe than the two pipe direct return hydronic loop. However, the flow is more balanced and even than the two pipe direct return hydronic loop. All baseboards and radiators receive the same temperature of water so is the same as the two pipe direct return. However, it is an advantage over the one pipe series hydronic loop. Zoning is also possible with a two pipe reverse return hydronic loop. Zoning will offer you savings on your heating bill. It does this by taking advantage of hydronic loop zoning and large pressure drop.

Conclusion | Boiler Water Loops

It should be noted that any piping system will be more efficient if the piping is insulated especially boiler piping.

To learn more about hydronics and boiler water loops use this resource.

Boiler Water Loops

Boiler Water Loops

Your Resource for HVAC Hydronic Piping Information

Pin It on Pinterest