Finding and installing Heating, Ventilation, Air Conditioning & Refrigeration (HVAC&R) applications for high-pressure systems has become more difficult as international regulations have eliminated some common refrigerants. R22, for example, is set to become illegal on January 1, 2020, due to its high global warming potential (GWP). With this in mind, the industry has begun developing Read more
Finding and installing Heating, Ventilation, Air Conditioning & Refrigeration (HVAC&R) applications for high-pressure systems has become more difficult as international regulations have eliminated some common refrigerants. R22, for example, is set to become illegal on January 1, 2020, due to its high global warming potential (GWP). With this in mind, the industry has begun developing sustainable, durable tubing materials.
Some copper tubing designated for HVAC&R applications does not provide the wall thicknesses necessary to handle the temperatures and pressures of carbon dioxide systems. However, copper-iron (C19400) material offers high strength, good thermal conductivity, and great workability, making it an exceptional, sustainable tubing option for HVAC&R applications. The C19400 alloy is rated for pressures in the range of 90 bar (1,305 psi) to 130 Bar (1,885 psi) and above at operating temperatures up to 300°F, compatible with the operating ranges of CO2 refrigeration systems.
Brazing techniques for copper-iron alloy are the same as those for brazed joints in standard copper and copper alloy systems for plumbing, HVACR, medical gas and other systems that require strong, leak-free, fatigue-resistant joints.
- First, measure the copper iron alloy tube accurately and precisely, so it will completely fill the socket when inserted into the fitting.
- Cut the tube square to the desired length.
- Deburr the inside edge of the tube and chamfer the outside edge.
- Clean the outside of the tube and inside of the fitting cup(s) to ensure the surfaces to be brazed are free from dirt, oxides or other contaminants that can impede the flow of filler metal into the joint.
- Assemble the joint by inserting the tube into the socket hard against the stop. The assembly should be firmly supported so that it will remain in alignment during the brazing operation.
- To conduct heat into the joint space, first preheat the tube. For a horizontal joint, begin preheating the bottom 2/3 of tube for a distance approximately equal to the depth of the fitting cup. When the tube begins to darken, begin heating both the tube and the fitting cup, focusing on the bottom 2/3 of the joint.
- Heat until the fitting cup reaches the proper brazing temperature; temperatures vary by tube size and type and can be found in section 14.4a of the Copper Tube Handbook.
- Apply heat to the parts to be joined, preferably with an oxy-fuel torch with a neutral flame. Heat the tube first, beginning about one inch from the edge of the fitting, sweeping the flame around the tube in short strokes at right angles to the axis of the tube (Figure 7.18, Position 1 [see below]). It is very important that the flame be in motion and not remain on any one point long enough to damage the tube.
- Switch the flame to the fitting at the base of the cup (Figure 7.18, position 2 [see above]) and heat the fitting cup around the bottom 2/3rds of the joint.
- As the fitting cup rises to brazing temperatures, begin to heat both the tube and the fitting by sweeping the flame (Figure 7.18, position 3) [see above] from the fitting to the tube until both the tube and the fitting reach the temperature at which the brazing metal begins to melt when applied to the copper-iron surface. Avoid excessive heating of cast fittings, due to the possibility of cracking.
- For 1-inch tube and larger, it may be difficult to bring the whole joint up to temperature at one time. It frequently will be found desirable to use an oxy-fuel, multiple-orifice heating tip to maintain a more uniform temperature over large areas. A mild preheating of the entire fitting is recommended for larger sizes, and the use of a second torch to retain a uniform preheating of the entire fitting assembly may be necessary in larger diameters. Heating can then proceed as outlined in the steps above.
- Apply the brazing filler metal at a point where the tube enters the socket of the fitting, near the bottom portion of the assembly. When the proper temperature is reached, the filler metal will flow readily into the space between the tube and fitting socket, drawn in by the natural force of capillary action. Keep the flame away from the filler metal itself as it is fed into the joint. The temperature of the tube and fitting at the joint should be high enough to melt the filler metal.
- Keep both the fitting and tube heated by moving the flame back and forth from one to the other as the filler metal is drawn into the joint and move the flame and filler metal smoothly and continuously up one side of the joint assembly. Once you reach the top, move back to the bottom of the joint on the other side and repeat the process, overlapping filler metal addition at both the bottom and top of the joint.
- When the joint is properly made, filler metal will be drawn into the fitting socket by capillary action, and a continuous fillet of filler metal will be visible completely around the joint. To aid in the development of this fillet during brazing, the flame should be kept slightly ahead of the point of filler metal application. Inspect to make sure there is a complete fillet around the joint, if necessary you can reheat the face of the joint and add additional filler metal to complete the fillet.
- For vertical joints, the starting point (bottom of the horizontal joint) is irrelevant but the same heating and brazing process should be followed.
- Cleaning is not a requirement once the brazing process is completed. If flux was used, the residue should be removed. This can most easily be done with hot water and brushing.
- Your joint is now complete! For additional information related to brazing copper-iron alloys and copper piping in HVAC systems, check out CDA’s Copper Tube Handbook.
Copper-iron alloy’s effectiveness under high pressure distinguish it as a top material for HVAC&R applications. The development of copper-iron alloy is a huge step forward in creating piping applications that are fit for the future environment. For more information about proper installation techniques for copper-iron, check out the video: Copper-iron Piping for HVAC, Lightweight but Strong as Iron.
Professionals in the commercial trades who have made the switch from copper or CPVC to PEX for plumbing or mechanical piping will tell you there are four main reasons why: speed, cost, reliability and safety. Because in today’s fast paced commercial building environment, change is rapid and inevitable, budgets and schedules are tight, competition is Read more
Professionals in the commercial trades who have made the switch from copper or CPVC to PEX for plumbing or mechanical piping will tell you there are four main reasons why: speed, cost, reliability and safety. Because in today’s fast paced commercial building environment, change is rapid and inevitable, budgets and schedules are tight, competition is fierce, and skilled labor is shrinking, so keeping valuable employees safe is paramount.
The commercial industry needs a piping solution that can meet all those very important needs, and PEX delivers on every front.
Because PEX pipe is flexible to bend with each change in direction and the connections are quick to learn and even faster and easier to make, it’s a great solution to meet the skilled-labor shortage challenge and also rapidly accommodate necessary changes in the field.
For example, a PEX piping system in an in-suite multifamily or hospitality project can reduce the number of required fittings by more than half compared to rigid copper or CPVC that require a connection with each change in direction. That can shave days or even weeks off the production schedule, depending on the project size.
Additionally, with today’s aging buildings, PEX is even more beneficial in re pipe applications where existing structures need minimal invasion for renovation (think: historical buildings).
When it comes to cost, every professional in the commercial world agrees — if the cost is attractive, but the product fails, it’s not worth it. PEX has proven to be both cost-effective and durable, a combination that makes it a win-win for engineers, building owners and installers alike.
Contractors are also finding it’s not just the material costs that are reasonable, it’s also the labor costs that PEX helps manage. Because the flexible pipe requires fewer connections (and those connections are faster and easier to make), it cuts down on labor costs in addition to the bill of material cost for the product.
With materials costing on average up to 30 percent lower than copper, and installs taking up to half the time compared to rigid systems like copper and CPVC, PEX is proving itself to be a smart solution that installers can rely on for consistent pricing, bidding and installations.
Every contractor has experienced a leak at one time or another, so a piping material that can help minimize leaks is a huge bonus. Take a look at all the ways PEX helps minimize potential leaks:
- Because the flexible pipe can bend with each change in direction, it reduces the number of fittings and connections and, in turn, the potential for leaks.
- With the PEX cold-expansion fitting system, it is impossible dry fit a connection. The expansion method requires the pipe to first be expanded before inserting a fitting. Then, as the pipe shrinks back down, it creates a strong connection onto the fitting. Eliminating the potential for dry fits means there’s never a concern if the connection is made.
- Flexible PEX is highly resistant to freeze damage because it can expand to accommodate frozen water in the system and then contract back down after the water thaws.
- PEX resists corrosion, pitting and scaling, so there is zero chance of leaks or performance issues due to any of these factors that can plague metallic piping systems.
With worker safety becoming a bigger issue — especially with the skilled-labor shortage — PEX offers benefits due to its lighter weight. For example, a 300-foot coil of ½-inch PEX weighs about 18 pounds, whereas the same amount of copper pipe weighs around 85 pounds.
Lighter weight means easier maneuvering around the jobsite, less strain on the body and a reduced need for cranes and heavy-lifting equipment.
Also, because all the PEX connection methods (cold expansion, crimp, clamp, compression or push-to-connect) do not need chemicals or open flame, it greatly reduces risk on the job site and also eliminates the need and cost for fire watch requirements.
One last word of advice
Stick with one PEX system brand. Mixing brands for the pipe, fittings, sleeves or rings can greatly reduce (or even void) the warranty. You’ll have more confidence knowing you have the backing of one company if you ever have a service or warranty issue.
If you’re interested in learning more about PEX pipe and fitting systems, visit the Plastics Pipe Institute website at plasticpipe.org or the Plastic Pipe and Fittings Association website at ppfahome.org.
Kim Bliss is the content development manager at Uponor. She can be reached at firstname.lastname@example.org.
Hot water heats and cold water cools. Simple, right? But for too long, the second part of that statement has been overlooked when it comes to the use of radiant systems. Radiant heating is widely used and growing in popularity, but its counterpart, radiant cooling, has been less popular, despite its many advantages over forced Read more
Hot water heats and cold water cools.
But for too long, the second part of that statement has been overlooked when it comes to the use of radiant systems.
Radiant heating is widely used and growing in popularity, but its counterpart, radiant cooling, has been less popular, despite its many advantages over forced air. And that’s despite the fact that both heating and cooling can be delivered by essentially the same system.
However, we’ve recently seen a surge in the popularity of radiant cooling as more engineers, architects, builders and consumers become aware of its comfort and effectiveness.
Anyone who’s ever worked in an office building knows the problems with forced air cooling: vents blasting cold air onto the necks of those unfortunate to sit right beneath them while others swelter in areas the ductwork doesn’t reach. Opening and closing ducts in an effort to get relief can throw the whole system out of balance while locked thermostats frustrate workers seeking relief. And, as if that weren’t bad enough, dust and allergens collect in the ductwork and are recirculated back into the air, aggravating allergies.
Radiant cooling eliminates those problems, providing even cooling and consistent temperatures without the noise and cold blasts of recirculated air and allergens. While minimal ductwork is still needed for ventilation and, in some cases, supplemental cooling, most of the work is done silently and invisibly below the floor (or in the ceiling).
Radiant cooling also is more efficient than forced air cooling, which wastes money and energy cooling ceilings and open spaces.
One barrier to the adoption of radiant cooling has been the misperception that it can’t be used in hot, humid environments for fear of condensation and the resulting slipping hazards.
However, that can be addressed through design and by setting the water to a temperature that prevents condensation. Coupling control of the humidity with control of the radiant floor, and a well-planned design, alleviate any concerns. Still skeptical? Consider this — radiant cooling is used at New Bangkok International Airport in Thailand, one of the most humid climates on earth.
Of course, correct design and building integrations are key to successful radiant cooling. Other cooling factors, such as green roofs, insulation and glazed windows, can lighten the load on cooling systems, while creating a harmonic and high-efficiency building.
While it’s easier and more efficient to design and install a dual purpose radiant system during construction, radiant cooling capability can be added afterward to an existing radiant heating system with little additional parts or labor.
With these many advantages, it’s only a matter of time before radiant cooling achieves the same prominence as radiant heating.
Brett Austin, Manager of Design Service, has been with Viega LLC for 10 years, beginning as a radiant design technician. He holds a bachelor’s degree in mechanical engineering technology from the University of New Hampshire and is a Marine Corps veteran.
Keeping occupants of a building or facility warm and comfortable is a year-round priority. Whether the leaves are turning, snow is falling or spring is blooming, maintaining the right temperature is key to ensuring occupants are happy and productive. Some buildings – such as yoga studios, swimming pools, hospitals and laboratories – require spaces to Read more
Keeping occupants of a building or facility warm and comfortable is a year-round priority. Whether the leaves are turning, snow is falling or spring is blooming, maintaining the right temperature is key to ensuring occupants are happy and productive.
Some buildings – such as yoga studios, swimming pools, hospitals and laboratories – require spaces to be kept at specific temperatures to ensure optimal performance for specialized activities. Yogis and swimmers perform better when they are warm, patients heal faster when they are comfortable, and researchers gather more accurate results when temperatures are constant.
For these and other types of retail and office facilities with unique heating demands, radiant ceiling panels are an optimal choice for providing consistent warmth without disrupting activities. The right radiant ceiling panels ensure a high level of comfort, and can be incorporated into the interior’s seamless warmth.
In a yoga studio or hospital, for example, the right interior furnishings and design are vital to creating a positive experience for occupants. Yoga studios are often simplistic in design to help calm those who are practicing, allowing them to focus on their poses and their breath. Similarly, studies have shown that the way a hospital is laid out and decorated has a significant impact on patient care and well-being.
Therefore, the addition of radiant ceiling panels should not alter these well-crafted designs, but rather blend the units into the existing surroundings as effortlessly as possible. Consider radiant ceiling panels specifically designed to act as invisible sources of warmth, able to match the color scheme of a room perfectly with paint or silkscreens so occupants don’t even realize they are present.
But hidden warmth refers to more than just visual customization. Areas such as yoga studios, locker rooms, office conference rooms, hospital ICUs and laboratories also want to keep their rooms quiet and without unnecessary drafts. A heating unit that produces strong air flow can spread dust particles and debris, while loud fans are disruptive to office productivity, quiet meditation and healing.
Radiant ceiling panels with no moving parts – such as fans – create no air movement or excess background noise, and therefore require no additional maintenance. Customizable options from QMark or Berko can be sized and colored to meet specific dimensions and themes, for a quick and silent addition.
A customizable heating unit should not only match the look of a facility, but its specific temperature requirements as well. One of the many benefits of radiant ceiling panels is their ability to provide primary or supplemental comfort. This means a building’s primary source of heat may be enhanced in specific spaces throughout where higher temperatures are required without overheating the rest of the facility.
In a yoga studio, some rooms may need to surpass 100 degrees Fahrenheit, while others can remain at a more standard room temperature. In lobbies, bathrooms and hallways as well, specific rooms may call for higher temperatures to enhance comfortability.
Radiant ceiling panels are able to offset perimeter heat loss from doors, windows or other sources of drafts. Likewise, they can provide primary heat to an entire space such as a yoga room without altering adjacent spaces’ temperatures. This ensures each space throughout the facility can have the temperature customized for the occupants’ needs.
To ensure radiant ceiling panels produce silent, invisible heat while keeping occupants safe, they must be made with the right materials. Galvanized or aluminized steel housing provides a stable base to hold the panels. Encapsulated casted element assures the units deliver uniform temperature across the surface, while increasing the panels’ longevity. Stability T-bar grip clips that can guarantee the panels stay intact during heavy storms or earthquakes are also important, as well as the use of fire retardant materials so there is no added risk in an emergency.
Some facilities may require specialized materials such as a stainless steel construction for chlorine storage areas that seal tightly with connectors and silicone. Exterior moisture and condensation do not affect heating panel performance, but water inside the unit can cause it to fail. Panels in locker rooms or swimming pools should be totally sealed with silicone at the factory before shipment to prevent moisture penetration. High-moisture facilities may also opt for seal-tight connectors and conduit, rather than greenfield flexible conduit and straight connectors.
When reviewing radiant ceiling panels for facilities with specific heating demands, consider all the options available as well as features to personalize. Berko and QMark offer customized radiant ceiling panels for a wide array of facilities looking to heat rooms with unique needs and uses. What may work for a laboratory setting may not be ideal for a yoga studio or swimming pool. Be sure to address all the different details of the space to ensure the needs are met and occupants can enjoy hidden, uninterrupted comfort every day.
Guest Blogger: Jim Herring is the supervisor of Total Custom Solutions & Technical Services at Marley Engineered Products®, a leading North American designer and manufacturer of reliable comfort heating and ventilation solutions for residential, commercial and institutional buildings. Recognized by contractors, architects, engineers and HVAC professionals for providing a wide range of high-performance, reliable heating and ventilation solutions, Marley Engineered Products’ brands include QMark®, Berko®, Fahrenheat® and Leading Edge®. Marley Engineered Products’ manufacturing operations are based in Bennettsville, S.C., with regional sales representatives located throughout the U.S. and an administrative office in Burr Ridge, Ill.
The cost of consumables can seem minor when calculating a job. Compared to the costs of labor, tools, material and transportation, the expenditure for consumables can seem unavoidable and of relatively minor importance. But when using traditional methods of joining pipe, such as welding, soldering and threading, consumables are a constant cost and one that Read more
The cost of consumables can seem minor when calculating a job.
Compared to the costs of labor, tools, material and transportation, the expenditure for consumables can seem unavoidable and of relatively minor importance.
But when using traditional methods of joining pipe, such as welding, soldering and threading, consumables are a constant cost and one that can easily cut into profit margins.
This sample bill of materials explains it well:
Say a job requires a contractor to make 1,500 x ½” pipe connections and, based on material and application, he chooses to use threading to join the pipe.
Consumables for the job are a cutting die, cutting oil, Teflon tape and pipe thread compound. Let’s look at the quantities involved:
- The ½” cutting die has a 1,500-cut life span.
- For those 1,500 cuts, two gallons of cutting oil are used.
- Three wraps of Teflon pipe are used on each pipe joint.
- One pint of pipe thread compound lasts five times as long as the Teflon rolls.
At face value, here are the price points associated with each of these consumables:
- Die: $123.48
- Cutting oil: $33.27
- Teflon tape: $15.78
- Pipe thread compound: $10.32
When you spread these numbers across 1,500 connections, you end up with a total cost of $0.318 per joint.
If you think about this from a long-term perspective, it’s easy to see where the dent in your budget forms. Perform the same job above 50 times over and the consumable bill reaches nearly $24,000.
Now, consider a scenario where you need a 2″ pipe joint to perform the above job. In this case, you have a total cost of $0.749 per joint. Perform this same job 50 times and your consumable bill stretches to more than $56,000.
(While on the topic of costs, it’s also worth mentioning that a threading machine alone will run you about $7,000.)
While the above example uses threading, other traditional pipe-joining techniques like soldering and welding introduce the same concerns over consumable costs. Whether you need spools of solder, flux and fuel or welding sticks, grinding discs and a galvanizing spray, you’ll have payments that never cease and are bound to add up.
The best way to eliminate consumable costs is to use press tool technology. While the greatest efficiencies with press technology comes with reduced labor costs, the savings on consumables will add up, job after job, year after year.
In addition, there’s no need for open flame and you’ll have the ability to install in any weather conditions, so you’ll avoid the cost of fire watches and hot work permits, as well as potential costly delays in project schedules due to environmental conditions.
Will Dutcher, Associate Product Manager – Industrial, has been with Viega LLC for three years, beginning as a product engineer. He holds a bachelor’s degree in mechanical engineering from The State University of New York at Buffalo (UB) and has engineering experience in a variety of industries, including pharmaceutical, high-end jewelry and consumer plastics.