Cutting Edge: Hydronics
The past several years have brought forth a new generation of technology in the hydronics industry. With European hydronic design influencing the marketplace, there's suddenly a most awesome array of European boilers, indirect DHW tanks, controls, PEX piping systems, thermostatic valves, radiators and specialty tools and hangers available to plumbing, radiant or HVAC contractors.
I confess to being a Europhile wethead. I know there are more ways to create superb hydronic systems using products and techniques beyond those discussed here. My intent is to focus on what has worked best in my experience with our business and our customers. Please don't feel offended if I've left out your favorites. You may be right about them.
Here's my “Hot List” for products that are simply outstanding and will change the way we design or install hydronic and radiant floor systems and potable domestic water piping.
Cutting Edge BoilersWall-Hung Condensing Boilers
The Viessmann Vitodens gas-fired boiler is the benchmark for state-of-the-art condensing boiler design. The wall-hung units offer extremely high efficiencies when used in condensing loads, have sealed combustion and direct venting. The integral computer control modulates the gas valve, the hemispherical MatriX™ burner, the exhaust vent fan and the circulator pump, making all components “smart.” The “Plug and Play” controls are unique in the industry and take the mystery out of control wiring.
The Vitodens is extremely reliable and compact. Here are the features:
- Highest efficiency with full modulation, combustion efficiencies of up to 98% when used in fully condensing load.
- Highly recommended for use with radiant floor heating systems that are designed for condensing boilers.
- Horizontal through-the-wall, or vertical venting with 6-inch Vitodens vent kit.
- Sealed combustion so dirt or dust cannot contaminate or foul the burner.
- High alloy stainless steel (SA316Ti) Inox-Radial heat exchanger designed for reliability and service.
- Protects the environment - extremely low emissions with modulating MatriX-compact gas burner.
- Compact, lightweight design with zero clearance to combustibles.
- Extremely quiet operation, quieter than most refrigerators.
- Smart burner technology, factory calibrated, self-adjusting burner. No adjusting in the field and reduced operating costs.
- User-friendly built-in outdoor reset control; pre-wired with LED diagnostics.
- Manages multi-temperature space heating and DHW production.
- Slave control for multi-boiler installations available for larger loads or light commercial projects.
Buderus is launching its wall-hung condensing boiler at ISH North America in Boston, Oct. 14 - 16. The boiler has been used in Europe for more than 10 years. It features an aluminum heat exchanger and an integral outdoor reset control.
The Buderus GA124 cast iron boiler features an induced draft design that is whisper-quiet. The venting system allows for direct connection of the combustion air with a single wall penetration. The GA124 is available in three sizes from 70K Btu input to 123K Btu input.
Buderus also manufactures its own outdoor reset controls (the Logamatic) and indirect fired hot water storage tanks in sizes from 42 to 120 gallons.
The Buderus “Solidiflux” wall panel radiator offers a reliable source of low-cost, high quality panel radiation in more than 30 different sizes and outputs.
The past few years have seen an abundance of wall-hung boilers or high-tech condensing boilers reach the marketplace. HTP's “Munchkin,” Burnham's “Revolution,” Weil-McLain's “Ultra” or Monitor's “MZ,” to name but a few. The market is ripe for innovation and ease of installation. The jury is still out for reliability and life cycle system costs for some of these appliances, since many of the new boilers have less than five years of service history. Contractors will need to carefully compare the differences between each appliance, with such wide choices available.
How about a plastic right angle adapter that will accept a TRV head on a radiator valve when there's no room to install a conventional TRV? The adapter will fit any long-throat circuit setter, (i.e., the Buderus wall panel radiators).
The Oventrop “Unibox” fits the bill for “most innovative hydronic product under $200.” This device allows individual room temperature control for small radiant floor heating zones (when radiators are existing) without having to add mixing controls or additional zone piping. When customers ask for a small zone of radiant (under 600 sq. ft.), the existing radiator can be removed in the room(s); the Unibox is then installed in the wall and piped from the old radiator supply and return. PEX piping forming the radiant loop(s) is connected to the Unibox, and the device limits the return temperatures via an adjustable circuit setter and thermostatic valve. The Unibox is about 6 inches wide by 9 inches high and will fit in a 2- by 4-inch wall. The device has an integral air purger and is easily installed to any standard PEX piping. No wiring required. Bravo Oventrop!
Several products from Grundfos meet the cutting edge criteria. The new “Miximizer” circulator is an integrated variable speed pump and outdoor rest control. The pump comes with an outdoor sensor and a return water sensor. The heating curve can be set on the integral pump control. The pump also features:
- Warm Weather Shutdown - disables the system above 70° F for greater efficiency.
- Pump Exercising - If the pump has not run for three days, the control spins the pump for 10 seconds to ensure longevity and prevent sludging of the pump volute and impeller.
- External “Call for Heat” Input - accepts demand signal for heat.
- Post Purge - after heat demand, pump will run for 20 seconds to purge remaining heat from system.
- Boiler Return Protection - If system water temperature falls below 135° F, the pump slows the water being injected into the zone, to prevent boiler condensation.
- System Temperature Protection - If zone water temperature approaches limit of 140° F, the pump slows the amount of water being injected to protect the floor coverings.
- The pump has a built-in check valve to prevent thermo-siphoning or the expense of an in-line check valve.
- It provides flexibility by having three speeds with a flow range of 0 - 17 GPM and a head range of 0 - 19 feet.
- This pump can replace more than 10 different circulator pumps, without having to carry the inventory or occupy space in the service van.
- The pump comes with a three-year warranty.
Many homeowners complain of having to wait for hot water, which also wastes energy and water. This pump can save thousands of gallons per year, per household, and installs in less than one hour.
The Taco Radiant Mixing Block (RMB) represents a breakthrough in the design, control and installation of radiant systems. The patent-pending design combines a variable speed injection mixing control, injection circulator, system circulator and air elimination into a single unit. Extremely versatile, the RMB can be set up to operate as an Outdoor Reset control, a Setpoint control or a Delta T limiting control. The unit is pre-wired and requires four pipe connections to complete the installation.
REMS has been producing tools for the pipe trades in Germany since 1909. The company exports its products and distributes in tandem with Mupro pipe hangers from a Los Angeles office. These tools ooze German quality and ergonomics:
- Threaded Rod Cutter, which will cut a piece of 3/8-inch rod without having to clean or deburr the threads.
- The REMS Amigo 2 Compact pipe threader, which at 10.5 pounds will thread up to 2-inch pipe.
- The REMS Ros P - plastic PEX or composite plastic pipe cutter.
- The REMS Powersaw ANC - electric orbiting reciprocating saw that's very lightweight and will cut up to 6-inch pipe, steel or plastic.
Panels, Pipe And Piping Systems
North American innovation, using Euro technique, has also played a part in designing and manufacturing products such as the Danfoss Zone Control Panel (ZCP) or Wirsbo proPanel. These products are a synthesis of hybrid design, combining the best of European and North American technology.
These panels are easy to mount, which means contractors save time and money.
“Essentially, the Wirsbo proPanel is a mechanical room in a box,” says Tim Doran, manager, Wirsbo Technical Services. With built-in flexibility, contractors can use a stand-alone proPanel (or ZCP) for a small application or connect multiple panels together to meet the needs of a more demanding application or commercial boiler setup. The panels put the “near-boiler” piping in a box, with no additional controls or wiring required.
PEX piping systems have been complemented by the introduction of composite PEX-Aluminum-PEX pipe in recent years. The pipe has an oxygen barrier and holds its shape upon bending. It's ideal for piping directly to radiant manifolds, baseboard or radiators. The pipe is also suitable for embedding within concrete or lightweight overpours.
It's an exciting time to be involved in this fast-changing industry. The products available from Europe may cost more, but in the long run, they represent significant time and labor savings to the contractors and energy savings for homeowners.