Weil-McLain Atmospheric Draft Steam Boiler Key to Overhaul Built at the turn of the last century in 1901, the seven-story Mendota is Washington D.C.’s oldest intact luxury apartment building. Though much of the building had been restored over the years, one area requiring attention was the facility’s heating system. Upgrading to a modern steam boiler Read More
Weil-McLain Atmospheric Draft Steam Boiler Key to Overhaul
Built at the turn of the last century in 1901, the seven-story Mendota is Washington D.C.’s oldest intact luxury apartment building. Though much of the building had been restored over the years, one area requiring attention was the facility’s heating system. Upgrading to a modern steam boiler restored the Mendota to its former heating glory, improving resident comfort and offering major energy savings.
The Mendota was built during the golden age of D.C. apartment houses along the trolley line in an area that was, at the time, considered the far northern suburb of the city. Today, it’s recognized as the first apartment building constructed in the residential neighborhood of Kalorama Heights.
“The Mendota is one of the grand old apartment houses in D.C.,” said Jim Wood, head of the building and grounds committee for the Mendota board of directors. “While many other D.C. buildings of the era have lost their visual character, the configuration of nearly every apartment unit in the Mendota is identical to when it was built.”
The Mendota’s 50 apartments include architectural details like 10-foot ceilings, ornate crown molding, tall windows, heart pine floors, built-in cabinetry and Victorian-tiled fireplaces. The apartment building was converted to a co-op in the 1950s.
Another historic feature is the Mendota’s original heating system – which consisted of a coal-fired boiler that’s still in place but has long been disconnected. The Mendota is heated by a one-pipe steam system connected to column-style cast iron radiators.
Over the years, the coal boiler was abandoned and a gas steam boiler was installed. But, that system, after many years in operation, had become less and less reliable.
“We allocated approximately $75,000 annually for natural gas, and this expense was a huge portion of our budget,” said Wood. “Also, many tenants complained it was either too warm – requiring them to open windows – or that they didn’t have enough heat. We had to do better.”
System Repairs Pick Up Steam
Dan Foley, president and owner of Foley Mechanical, Inc., based in Lorton, Va., was selected to help remedy the heating woes.
“When we started working with Mendota, a 40-year old steam boiler provided heat,” said Foley. “Upon inspection, we noticed the boiler fired all day long and never shut off.”
Foley also noted that the main venting system was not appropriate for the two 6-inch steel mains that circled the basement of the facility. The boiler would flood on a regular basis, and the condensate would lag as it percolated through the clogged wet returns.
“When the condensate would finally return, the boiler would flood, which required a service call,” said Foley. “Water continuously drained from the boiler as fresh water was added, causing the boiler to disintegrate from the inside out.”
Foley and Wood decided first to make incremental improvements to the aging boiler. Enhancements included replacing multiple ribbon burners that had rusted, and replacing the boiler relief valve and safety controls. Next, the team rebuilt the main venting system.
“The vents were undersized and the two mains were not balanced,” said Foley. “We had a welder cut in two 1-inch thread-o-lets into the end of the steam mains, and then we built vent headers on each main.”
Another step was removing an old electro-mechanical control that had not functioned properly in years.
All of the boiler system improvements had a fairly dramatic effect on tenant comfort and energy usage. The boiler heated the building more evenly and fuel expenses decreased to between $55,000 and $60,000 annually. However, Foley believed there still was room for improvement.
When service calls began to become a weekly occurrence and most of the operational parts of the boiler were replaced, building management decided it was time to consider replacement.
Installing a Weil-McLain LGB-20 atmospheric draft steam boiler improved resident comfort and offered major energy savings for the Mendota.Boiler Replacement Full Steam Ahead
After several years of maintaining the aging boiler, Foley recommended installing a new boiler, re-piping the header and replacement of the rotted, clogged wet returns.
“I submitted a six-figure proposal, and at first the board balked at the price,” said Foley. “When I suggested they review what they paid in fuel over the past five years and add in the service calls and tenant complaints, they quickly came around.”
Foley recommended installation of a Weil-McLain LGB-20 atmospheric draft steam boiler at 2.5 million BTUs. At up to 84% combustion efficiency, the LGB line is one of the highest efficiency commercial cast iron atmospheric gas boilers available from Weil-McLain. Its compact design allows for more piping and venting headroom and the unit’s short draw rods permit faster, easier assembly of boiler sections.
The boiler was sized to the connected radiation using a 1.5 pick-up factor. The header was re-piped to manufacturer specifications.
“Before we removed the old boiler, we conducted a system overhaul to optimize the distribution piping, vents and the radiators in every room,” said Wood. “We then installed new main line steam vents, both at the beginning and the end of the line, checked all the mud legs and replaced the near boiler piping because it had been clogged.
“Our preparatory work and due diligence ensured the whole system would work much more efficiently and we could slip the new unit right in,” Wood added.
The project took two weeks to complete. Installation challenges included navigating stairs and working in a small space.
After the new boiler was installed, the team cleaned the system with steam cleaner and ran it for several weeks to flush out all of the sediments. After flushing the boiler and wet returns, Foley skimmed the water line until it ran clear.
Loop seals also were clogged with sediment. Foley and team meticulously flushed out each loop seal with water, which allowed the condensate to drain and the steam to flow freely. This process helped balance the system.
New System Benefits
With the new boiler optimized and in service, several benefits were quickly realized. Radiators that had not heated in years were hot. Steam circled the mains quickly and the risers received steam at the same time. Windows previously opened in January were closed.
“We actually installed a couple of dozen additional radiators that had been removed with the previous system because it had been run at such a high level that the building was overheating in some areas,” said Wood.
And Wood likes the fact that he doesn’t have to change the operational parameters of the boiler throughout the year.
“The controls are such that we don’t make adjustments at all,” said Wood. “The system learns and fine-tunes settings as needed.”
One of the most significant benefits of the new, higher efficiency Weil-McLain boiler installation was the energy savings realized. Fuel costs for the building decreased to about $30,000 annually – a significant reduction of more than 40% from gas bills years earlier.
Additionally, the system operates quietly.
“When the boiler turns on and the radiators are operating you sense the heat but you don’t hear anything,” he said. “It just purrs.”
And, most importantly, tenant complaints were reduced.
“I believe that steam boilers with radiators really is just the most perfect, comfortable heating method,” Wood added. “We have been absolutely pleased and impressed since the new boiler was installed. And, we’ve saved a lot of money.”
A medical center in Chicago required a quick and efficient remedy to nurse its aging and failing boiler heating system back to good health. The newest high efficiency condensing boilers from Weil-McLain provided the medicine needed. Larry Latas, system director for multiple medical facilities in Chicago, needed to upgrade the aging boiler at the 15,000-square Read More
A medical center in Chicago required a quick and efficient remedy to nurse its aging and failing boiler heating system back to good health. The newest high efficiency condensing boilers from Weil-McLain provided the medicine needed.
Larry Latas, system director for multiple medical facilities in Chicago, needed to upgrade the aging boiler at the 15,000-square foot Presence Health facility.
“We had several issues with controls, the boiler was leaking, and we had to place multiple services calls to keep it operating effectively,” said Latas. “We were exploring grant programs for energy savings projects, such as boiler replacement, and that’s when we were approached by Carl Wigginton.”
Wigginton, vice president of service at Murphy & Miller Inc., a Chicago-based HVAC mechanical services firm founded in 1936, handles heating maintenance at Presence Health.
“Presence had an old 1 million BTU atmospheric steel tube boiler that was only functioning at maybe 700,000 BTUs,” said Wigginton. “Additionally, it was leaking and was strictly an on/off boiler that was wasting energy.”
Latas’ wish list included installation of an energy efficient system that offered Modbus communication so the facilities technician could remotely access the boiler through the building automation system (BAS), view the status and determine how the system was functioning.
Wigginton recommended that Presence participate in a field trial for a condensing boiler that had just hit the market: the 95% AFUE Evergreen™ boiler from Weil-McLain.
The Evergreen features advanced technology with simple controls, flexible functionality for multiple applications and a durable design, and is easy to install, use and maintain.
The unit is adaptable for most heating needs including light commercial or large residential applications and for single or multi-boiler installations.
“The old atmospheric boiler was piped in series with the system, and when it was running it was about 65% efficient, versus the Evergreen that is 95% efficient,” said Mike Gambill, commercial specialist at Weil-McLain, who helped manage the project. “Because they were continuing to flow water through the boiler when it was not firing, it essentially became a radiator that robbed energy from the system and sent it up the chimney.
“When you run water through a boiler that’s connected to a system but not firing, it’s extracting energy from the system,” added Gambill. “It’s often not measured, but we refer to this as off-cycle losses.”
To improve heating efficiency, both Wigginton and Gambill recommended piping two 399 Evergreen boilers primary-secondary so the boilers are hydraulically disconnected from the system when not operational. Primary-secondary piping offers a simple way to inject heating energy into a system regardless of the flow rate in the heating system main piping. This flexibility and simple operation make primary-secondary a very popular configuration for piping boilers.
Boiler Installation and Specifications
The Presence Health facility consists of a main air handler and approximately 22 variable air volume (VAV) boxes that open or close based on the specific reheat demands in a particular space of the building.
“With 22 VAV boxes, the 1 million BTU boiler was constantly turning on and off or short cycling,” said Wigginton. “The two Evergreen boilers feature full modulation firing with up to a 10 to 1 turndown. Thus, one boiler is able to modulate all the way down to the smallest load or as low as 10% of a single boiler. This keeps short cycling to a bare minimum because the unit can match the required load with the least amount of fuel.”
Boiler turndown ratio is: the maximum heat output reducing to the minimum level of heat output at which a boiler will match the heat load efficiently.
“The Evergreen units are ideal for an application such as Presence Health with 22 VAV boxes,” said Gambill. “Evergreen boilers have a maximum turndown of 10 to 1 each. We found that further turndowns beyond this ended up with more energy in the flue than in the heating system.”
The first installation challenge was removal of the old, heavy boiler, which had to be disassembled in pieces due to its size and weight. Before removal, Wigginton recommended flushing the old system while the atmospheric boiler was still in place to clean the pipes.
With flushing and removal complete, the two Evergreen units were placed on a hand cart, rolled into the facility’s elevator, through a standard doorway in the mechanical room and were placed on the same concrete pad as the original boiler.
Converting the system to primary-secondary piping required some piping modifications. Murphy & Miller removed the old boiler and cut the piping that was in series and connected the headers with two closely spaced tees, creating a primary-secondary connection for the boilers.
The intake and exhaust were then vented through the roof, using the same chimney that was utilized by the atmospheric boiler.
The Evergreen boilers also were installed with a built-in sequencing controller (with lead-lag rotation) that was converted from Modbus® to BACnet® to fit the protocol of the building automation system.
Additionally, the boilers were set up as a lead-lag system to avoid one unit running more than the other. The units were configured to rotate lead every 24 hours to the next boiler.
“Installation took about two weeks to demo, cut out, re-pipe, install and operate the new boiler,” said Wigginton.
“We’ve partnered with Carl Wigginton and Murphy & Miller for years,” said Latas. “Carl is a terrific service manager and provides excellent support, and they are a great company to work with.”
A Clean Bill of Heating Health
Presence Health has experienced several benefits as a result of the heating system overhaul. One, is reduced fuel expenses.
“We’ve experienced energy savings by replacing the standard boiler with higher energy efficient units,” said Latas.
Another plus, according to Latas, is the reliability of the units.
“We didn’t have a single service call on the boilers through all of last year’s heating season, which says it all for the quality of the units we installed,” added Latas.
With failing boilers and an inefficient heating system, historic Zion Episcopal Church in Oconomowoc, Wis., needed guidance and help. New, high efficiency condensing boilers from Weil-McLain provided the answer to solve their heating woes. Zion Episcopal Church is a Wisconsin landmark founded more than a century and a half ago. In 1846, the Rt. Reverend Read More
With failing boilers and an inefficient heating system, historic Zion Episcopal Church in Oconomowoc, Wis., needed guidance and help. New, high efficiency condensing boilers from Weil-McLain provided the answer to solve their heating woes.
Zion Episcopal Church is a Wisconsin landmark founded more than a century and a half ago. In 1846, the Rt. Reverend Jackson Kemper, the first missionary Episcopal Bishop, established the Zion Episcopal community in Oconomowoc. The present day stone church situated on Fowler Lake was built in 1889.
“Our heating system consisted of four nearly 12-year old 199 MBH boilers,” said Linda Georgeson, senior warden with Zion Episcopal Church. “Two of the four boilers were no longer functioning, and we were convinced the other two would fail because one was leaking.
“We were quite distressed to have such failures on this large purchase of units that were considered state-of-the-art when we bought them,” she added.
The boiler manufacturer offered to honor the warranty and install new units, but Zion declined. Instead, Georgeson requested bids from three mechanical contractors, including local Oconomowoc, Wis. firm Schulte Heating. Schulte submitted a bid to install Weil-McLain boilers, while the two other firms proposed installing different manufacturers’ equipment.
“We invested a lot of time researching and evaluating commercial boilers and reviewing the proposals we received,” said Georgeson. “In an open meeting of the church, we charted cross comparisons of all of the different units, the associated costs and warranties, and who would handle installation.”
In the end, Schulte Heating and Weil-McLain came out on top.
“We chose Weil-McLain Evergreen units because we thought the engineering was excellent, and the system design seemed attractive in terms of overcoming our issues,” said Georgeson. “We also liked the warranty, the ability to easily service them and that Schulte Heating was a local firm.”
Rich Schulte, Jr., vice president of Schulte Heating, oversaw the boiler upgrade project.
“Upon our analysis, in addition to having unreliable boilers, the church also had quite a bit more capacity than they needed with the four previous boilers,” said Schulte. “And, the church knew it had to act quickly because they wouldn’t be able to heat the building with only one functioning boiler.”
Installing Evergreen Units
In September 2015, church staff determined it was time to proceed with the project, and the Evergreen units were installed in October.
Schulte Heating replaced the four failing boilers with two Evergreen boilers, a 299 MBH and a 399 MBH; they were installed as a Multiple Boiler System (MBS) using the Modbus Communication feature. In this configuration, a master boiler controls the modulation and sequencing of boilers on the network to achieve the desired system supply temperature.
“With the automatic sequencing feature, the boilers communicate directly with one another so they sequence themselves and rotate as needed,” said Schulte. “Both operate at the lowest rate to optimize efficiencies.”
The new 95% AFUE Evergreen from Weil-McLain offers simple controls, flexible functionality for multiple applications and a durable design, and is easy to install, use and maintain.
The units are adaptable for most heating needs including light commercial or large residential applications and for single or multi-boiler installations. Evergreen offers quiet operation, an aesthetically pleasing design, floor standing or wall mount options and environmental sustainability.
“Evergreen is the only boiler I proposed to Zion because I really like the technology of the fire tube heat exchanger in those boilers,” said Schulte. “In addition, they are easy to set up through the set-up wizard option provided on initial start-up and also easily maintained.
“Another important feature is the units don’t require a separate, external control panel or boiler panel, and that was ideal because the church did not currently have a separate interface to view the status of the systems,” said Schulte. “It’s now very easy to see the system status and service the units, if needed.”
The installation took less than a week.
Boiler Upgrade Benefits
Georgeson is already seeing efficiencies with the new units, though installed for less than a year.
“We’ve noticed a significant savings on our energy bills when comparing this year’s monthly bills to last year,” said Georgeson. “This was not surprising as we expected to experience energy savings based on the high efficiency of these boilers. We imagine we will save hundreds of dollars in the long term.
“The Evergreen boilers also are very reactive to our heating needs,” said Georgeson. “The units keep the baseline water temperature at a level where they can react quickly if additional heating is required, such as when our church doors open on Sunday morning.”
The units are configured to handle the five separate church thermostats/zones. Each thermostat is programmed for usage depending on the day and whether the area is occupied.
“I can control temperatures throughout the church when people need heat or when I can keep it low,” she said. “The units are very responsive for zone use.”
Georgeson also appreciates the easy-to-use interface.
“I can even reboot the boilers myself if needed because the interface is very user-friendly,” said Georgeson.
The two Evergreen units also allow for more space and access in the boiler room.
“It’s not an overcrowded area anymore because we have two appropriately sized boilers handling the heating load of the church instead of four,” said Georgeson.
Schulte Heating will handle annual maintenance to keep the units in top working order.
“Schulte Heating’s workmanship was excellent, and I am very satisfied with the performance of the units,” added Georgeson.
With failing oil-fired boilers and an aging, inefficient heating system, Elm Street School in Gardner, Mass., turned to modulating boilers from Weil-McLain to spark energy efficiencies and lower heating costs for the school. Built in 1923, Elm Street first served as a high school, but over the course of numerous years, the district converted the Read More
With failing oil-fired boilers and an aging, inefficient heating system, Elm Street School in Gardner, Mass., turned to modulating boilers from Weil-McLain to spark energy efficiencies and lower heating costs for the school.
Built in 1923, Elm Street first served as a high school, but over the course of numerous years, the district converted the facility into an elementary school. Today, the 130,000-square foot facility houses more than 500 students.
“Our heating system consisted of two nearly 20-year-old boilers that were in constant need of repair,” said Robert O’Brien, director of facilities for Gardner Public Schools. “We found ourselves changing out cast iron sections on an annual basis. In addition to the maintenance issues, we wanted to decrease our overall heat load.”
To assist with project funding and help cover boiler replacement costs, the school applied for and received a green repair grant from the Massachusetts School Board Authority (MSBA). The MSBA Green Repair Program offers districts the opportunity to repair or replace roofs, windows and/or boilers in public school facilities that are otherwise structurally, functionally and educationally sound.
With funding in place, the school selected, MacRitchie Engineering, based in Braintree, Mass., which provides HVAC, plumbing and electrical design services, to handle the boiler replacement.
“We sought a dual combination gas and oil commercial boiler and Weil-McLain was my primary choice,” said O’Brien. “We also wanted units with the ability to modulate with a control package that could be implemented into a building management system.
“We received three competitive offerings when the project was put out for bid and we chose Weil-McLain because the equipment had the best load matching characteristics,” said O’Brien.
The team chose three Weil-McLain 88 Series low pressure steam boilers as the optimal choice to match heating load requirements with two carrying the building load and one installed for redundancy. MacRitchie also was tasked with handling oil conversion to add gas for dual fuel firing, boiler room valves, boiler feed unit, fuel oil pumps and controls, and associated electrical and plumbing work.
The Weil-McLain 88 Series boilers offer up to 85.7% thermal efficiencies, are operational in single or multiple systems as gas, oil or gas/oil, and feature modulation control.
The old oil-fired burners were removed and replaced with the Weil-McLain dual fuel boilers and configured with gas as the main fuel source and oil as a backup. Each boiler was installed with its own pump plus a common manually valved standby pump.
The project was completed and the units were placed in operation in October 2015.
Built in 1923, Elm Street School in Gardner, Mass., houses more than 500 elementary students.
Numerous Benefits Realized
According to O’Brien, the installation went smoothly and the school already is experiencing benefits.
“We expect to save anywhere from 20% to 25% of our fuel costs with these new boilers because they are more energy efficient, feature low-range pressure controls and have the ability to modulate,” said O’Brien.
Modulating burners are designed to control the burner output to match the boilers’ variable load requirements to ensure maximum combustion and boiler efficiencies during large heating demands. The modulation feature also has decreased the system pressure.
“Thanks to modulation, we reduced the amount of operating pressure from about 10 pounds on a cold day to about 5 pounds,” said O’Brien. “Dropping the pressure created a lot of savings, yet we are still maintaining the temperature inside the building so that’s a definite plus.”
Other benefits O’Brien and building staff are realizing include the adoption of a building management system that will send notifications via email and sound an audible alarm in the school if an issue should arise.
“If a boiler burner should misfire, for example, I immediately get an email and an audio alarm goes off in the school,” said O’Brien. “This alerts school custodian staff that an issue is happening, and it’s an important safety feature to have.”
The expected duration and life of the boilers are another plus, according to O’Brien.
“The life expectancy is typically 30 or more years for these boilers,” he said.
The Waldinger Corporation has used Viega systems with great success for many years, so when given the choice to use them for one of the most prominent construction projects for the city of Wichita, they were happy to oblige. The Waldinger Corporation was subcontracted by the general contractors, Key Construction and Walbridge, the mechanical work Read More
The Waldinger Corporation has used Viega systems with great success for many years, so when given the choice to use them for one of the most prominent construction projects for the city of Wichita, they were happy to oblige.
The Waldinger Corporation was subcontracted by the general contractors, Key Construction and Walbridge, the mechanical work at the new Dwight D. Eisenhower National Airport.
Formed in 1906, Waldinger has offices throughout the midwest including Wichita, KS. The Viega name and its products were nothing new to Waldinger. They knew that Viega’s press technology has the ability to save time and money by eliminating the need to solder every joint, and the Smart Connect® feature offers a secure pipe connection every time by allowing installers to easily identify unpressed connections during pressure testing.
“I started using Viega ProPress when it first came to the United States,” Matt Hildreth, Construction Division Manager for The Waldinger Corporation said. “We were excited to learn we could use it on this project.”
Wichita’s new Dwight D. Eisenhower National Airport is the city’s latest addition to aviation and the first and last impression visitors will see upon arrival to the city. In June, Wichita said goodbye to its 61-year-old airport terminal and opened doors to a new 275,000 square foot home.
Known as the Air Capital of the World, Wichita’s airport is aviation themed inside and out. The building makes you feel as if you are entering an aircraft, with those details carrying over indoors. A swooping roof line outside, decorative stainless steel walls, public art and aviation history pieces inside, the airport is one-of-a-kind. A terrazzo floor designed with inspiration from the contrails of aircraft flying will guide the two million passengers through the airport each year.
The airport is equipped with the latest technology, food services, parking garage, baggage claim and loading gates. The Dwight D. Eisenhower National Airport was made of quality products, including Viega systems, designed to make traveling in and out of Wichita quick, efficient and easy. It features 23,000 square feet of radiant floors, 8 ½ miles of gas and hydronic lines and 267 plumbing fixtures.
The Waldinger Corporation installed Viega’s ProPress® copper in ½” to 4″ in the domestic potable water applications. They also used ViegaPEX™ Barrier and Viega FostaPEX® tubing for a Snow Melting system and a Viega ProRadiant™ heating system in the behind the scenes area of baggage claim, in parts of the tarmac, the main entry and the loading dock. While most of their work and Viega’s systems are hidden, Waldinger knows the important stuff is behind the walls.
“The guys all like going ‘look at this mechanical room.’ All the boilers are perfect, all the piping is perfect that’s how we do our work,” Hildreth said. “It’s what’s hidden in the walls. It’s what’s in that mechanical room and behind that wall that makes this work.”
Press innovations allow mechanical contractors like Waldinger to not only save time, but also money. A highly engineered system, it’s the time savings and quality that contractors are using to sell their customers.
“Our opinion is that we are going to do it at least 20% better,” Hildreth said. “It’s what we use as a standard of bidding. We’ve smoked that estimate on occasion.”
Its functionality and reliability are part of the driving force, but the value added is with the customer service clients receive from the sales representatives. Viega will drop what they’re doing, pick up the phone or turn their car around and head to the job site to consult on a project. On a project the size of the airport, that kind of commitment was invaluable for The Waldinger Corporation.
“Lucky here for us, with you guys being here and having a sales person that was so active with us, if you have somebody here taking care of you and really working to help you, you’re going to be more apt to use their product,” Hildreth said. “Customer support was fantastic. You’re one of the few manufacturers that do that.”