New Solution to an Age-Old Problem

Ask any heating man what is the most common cause of hydronic heating problems, and he’ll tell you air! Air can be the source of all kinds of problems including unbalanced heating zones due to air binding. It is a great insulator, reducing the heat output of baseboard zones, which in turn creates higher fuel bills for your customer. It can also damage pump seals and bearing assemblies. But the most common complaint of air in hydronic systems is the gurgling, “waterfall”-like noises that result in a service call to your customer.

Did you ever think about where this air comes from or why it always seems to make its way into the bedroom zones? Well, it comes in with the cold make-up water used to fill the system.

You can’t see this air because it is dissolved in the cold water (like sugar in coffee!). But as soon as this cold water is heated by the boiler, the air comes out of solution in the form of air bubbles. You see, hot water can’t hold as much air in solution as cold water. If these air bubbles aren’t caught right at the boiler, the circulator will send them flying out to the piping system at a speed of 4-5 feet per second. This explains why, when you place float vents throughout the system, they do nothing to solve the problem. The air just whips past these vents as if they weren’t even installed.

The answer is to install a good air separator right near the outlet side of the boiler to catch these “bubbles.”

Typically, the traditional “airscoop” has been installed incorrectly, which only adds to the problem. On most of these jobs, you end up going back and purging the air out of the system. Of course the water used to purge the system is cold and holding a large amount of air in solution. Once heated, the air again comes out of solution in the form of bubbles and makes its way out to the system. Eventually you’ll get the call complaining about the “air problem” again and you’ll go back to purge it out! This is like a dog chasing his tail!

There’s Got to be a Better Way!

Bell & Gossett recently introduced a concept on how to effectively pipe residential hydronic boilers. It is called the HYDRO-FLO module, and it provides a cost-effective method to assure the system will operate free of air-related problems, while providing a quiet, efficient hydronic system. The HYDRO-FLO module reduces the contractor’s installation time and the components can be easily serviced!

The Hydro-Flo Module

The heart of the HYDRO-FLO module consists of B&G’s EAS which is our new enhanced air separator. This device uses a coalescing medium which acts like “thousands of little fingers” snatching the air bubbles out of the water as it flows through the unit. In addition, they surround the coalescing medium with a diffuser plate. This plate spreads the water across a greater percentage of these “fingers,” increasing their effectiveness.

From an installer’s perspective, what’s unique about this unit is its inlets and one outlet (like our SA Flo Control valves.) This means you can pipe the EAS right into the vertical supply riser coming up out of your boiler. The air separator is so effective, no minimum pipe diameters are required to install it. On the outlet connection you should install your system/zoning circulators and Flo-Control valves or system circulator and zone valves. Instead of plugging the horizontal inlet port, you can locate the diaphragm compression tank, a pressure reducing valve and a pressure gauge, all installed on a conventional piping cross.

Easy to Install, Easy to Service!

By simply installing a boiler drain in a tee fitting on the supply riser out of the boiler, and service valves on each zone, you can POWER PURGE individual zones from this one drain and hose connection. Don’t forget to locate the boiler drain below the EAS and the supply riser’s service valve. Now when it comes time to service any of the hydronic components, simply close each zone’s service valve and the supply riser’s valve, and you have access to all the components without draining down the system!

If you need more information or have any questions about HYDRO-FLO, contact your local Bell & Gossett Representative.