Domestic Water Booster System | Metropolitan Industries

Iowa Weslyan College Upgrades Heating System, Decreases Carbon Footprint

June 13, 2012

Campus Heating System Upgrade at Iowa Wesleyan College Helps Lower Costs While Decreasing Its Carbon Footprint

Iowa Wesleyan College is a private liberal arts college located in Mount Pleasant, Iowa. Metropolitan Industries recently installed new packaged boiler systems in five campus buildings to bring the school a more cost-efficient heating system.

In its distinctive role among the many institutions of learning in America, Iowa Wesleyan College adheres to the ideals of its founding vision of social justice and human welfare on the local and international level by seeking to decrease its carbon footprint. In an attempt to bring a cleaner, greener and a more cost efficient heating system to their school, Iowa Wesleyan, in conjunction with Energy Systems Group, decided to replace their existing, centralized hydronic heating system with several more efficient, complete packaged boiler and primary piping pump systems from Metropolitan Industries.

ESG designed a system so that each building’s heating system would have equipment pre-assembled and manufactured for ease of installation. ESG decided Metropolitan Industries, the leading manufacturer of complete boiler and primary piping pump systems, was the right supplier for equipment development and construction. The campus heating system upgrades also included additional geothermal heating/cooling facilities.

“After a few discussions about the design, we decided to provide high-efficiency, pre-packaged hybrid boiler systems assembled on prefabricated skids with the associated primary piping and pumps,” said Metropolitan’s HVAC Sales Manager Matt Brickey. “This type of design would allow for ease of installation by the contractor and reduce installation time dramatically. We realized moving the prefabricated system through the tight hallways and doorways posed a challenge, so the system was designed so that it could be manufactured in a way that split the skid in three different spots allowing for easier moving and maneuvering around tight spaces.”

The custom designed and engineered boiler systems were installed in five campus buildings: The McKibbin Dormitory, Student Union, Science Hall, Campus Library and the newly-renovated Chapel. In the McKibbin Dormitory and Student Union, hybrid boiler systems with heat exchangers were also packaged on the systems to satisfy the domestic hot water load.

High efficiency air separators manufactured by Spirotherm® were utilized to remove unwanted air that may have found its way into the system during the installation process. Spirovent® technology is designed to address all forms of air (entrapped, entrained and dissolved) that can be found in closed loop systems and remove nearly all of it. The coalescing medium creates a low velocity area inside the Spirovent® that allows air bubbles to rise and dirt to sink. There are no strainers, filters or replacement parts that can potentially become clogged. The flow always remains constant, without a high-pressure drop.

The end result is increased distribution efficiency, component life and heat transfer capabilities, along with decreased oxygen-based corrosion and pump cavitation, and the elimination of air related noises within the entire piping system.

A packaged boiler system prior to installation. This system was installed at Iowa Weleyan’s Library.

In regards to Iowa Wesleyan’s energy consumption concerns, the primary reason for utilizing a modulated conventional boiler AND a condensing boiler is simple–together they are more efficient, have a lower initial cost and last longer.

For Iowa Wesleyan, the implementation of the hybrid boiler system was the ideal solution for their new campus heating system. They were able to save some upfront costs by purchasing a “standard” efficiency boiler, but were still able to benefit with the energy savings through the use of the high efficiency condensing boiler when conditions would allow.

Combustion air temperature also affects the net efficiency of the combustion process. Cold combustion air will absorb more energy released from burning the fuel than warmer combustion air; meaning colder combustion air reduces the efficiency of the appliance.

Lower return water temperatures and lower flue gas temperatures provide the best condensing operation. The condensing boilers recover the latent heat that is usually lost by harvesting the energy that is created when the water vapor in the flue gas is turned into a liquid.

When a customer’s boiler system is more efficient, it will not only save the customer money each year, it will also decrease their carbon footprint. The efficiency of the boiler system in part depends on the temperature of the return water. When the return water temperature is 130 degrees Fahrenheit (54.4 degrees Celsius) and above, the control system will run the conventional boiler. At 129 degrees Fahrenheit (53.9 degrees Celsius) and below, the control system will run the condensing boiler. The savings are maximized in temperate climates where winters are cold and summers are warm.

When the system uses the condensing boiler, the amount of usable, sensible heat that is generated is significantly larger than that of a conventional boiler system–creating true system efficiency.

Why not just use condensing boilers?

It may seem as if the perfect boiler system would simply use condensing technology. But if return water temperatures are too high, the condensing boiler will be only as efficient as a conventional type boiler. In a condensing boiler, when the temperature of the return water is too high and the air temperature is too cold, it will not allow a condensing boiler to operate in condensing mode. Initial capital costs can be reduced with a hybrid system by combining a lower cost conventional boiler with a premium efficiency condensing boiler.

Due to Iowa Wesleyan’s upgrades, carbon emissions are expected to reduce, which will translate into savings in total energy costs.

Every customer’s needs are unique and Metropolitan can tailor the solutions to meet your needs.

“What’s nice about these systems is that they’re completely customized to the client’s needs,” said Brickey. “Metropolitan Industries can configure the piping, boilers and system components in any manner to ease the installation process for a new or retrofit application.”

In the case of Iowa Wesleyan College, the savings are significant.

For more information regarding HVAC products, please contact Matt Brickey at 815-886-9200, ext. 266 or sales@metropolitanind.com.

Hybrid Boiler System Package and Primary Pump System

New hybrid boiler system package and the primary piping pump system recently installed at Iowa Wesleyan’s Science Hall.

November 17, 2010

Reduce Boiler Fuel Consumption by 50 Percent

HVAC Sales Engineer Matt Brickey operates the new boiler system during start-up of the system.

The life blood of any commercial building is the mechanical systems running behind the scenes that include domestic water booster systems, fire suppression pump systems and HVAC systems.

Of the three mechanical components, HVAC is by far the largest consumer of energy due to the sheer nature of how they are specified and designed. The school of thought in the HVAC community is size everything for peak demand without considering demand fluctuates, especially during warmer months when demand is at the lowest.

The biggest misconception when specifying a boiler system is, “If I specify a boiler at 90% efficiency then the plant will operate at 90% efficiency.” This is false because during light load conditions, such as during warm months, boiler efficiency becomes random which results in poor overall, “cycle” efficiency. In other words, “Seasonal Efficiency,” is only 50-80% of measured efficiency resulting in no realized energy savings during the warm months when your boiler runs less.

Metropolitan Industries, Inc., located in Romeoville, Ill., has a solution that reduces boiler fuel consumption by 20-50% using a patented procedure that addresses seasonal efficiency, which increases cycle efficiency therefore reducing fuel consumption dramatically.

Case Study – Multi Occupancy Condominium

A great example of this technology was demonstrated by the work done at a 139 unit Condominium located in Will County, Ill. At the request of the owner, the building name and location of the project is to remain confidential.

To address the leaking heating pumps located in the ceiling, Metropolitan had the contractor move them to floor level for easier inspection and service.

The existing system had two problems the first being the plant ran inefficiently due to the boilers being the sole heat source for the domestic water. Due to this, they operated all year round, even during the summer months. The inefficient design operated by pumping city water and boiler water through a shell and tube heat exchanger mounted near the ceiling. Since there was no way to prevent gravity flow of hot water through the heating system return lines, the radiation caused the building to stay warm all year, even in the dog days of summer. This resulted in increased fuel consumption and increased electrical consumption as well because air conditioners witnessed an additional load imposed by the uncontrolled flow of unwanted heat from the boiler plant and needed to run overtime.

The second problem was the existing heating pumps were leaking and had been since day one. There were eight zone pumps serving four zones. Three zones were for space heating and the other zone for domestic hot water heating. The reason why they leak was because they were mounted near the ceiling without the proper supports. This made it difficult to service the pumps given a technician need to perform the work on a ladder.

Green Performance Solution

To solve the inefficient operation of the plant, Metropolitan Industries installed a “summer boiler,” sized to the requirements of the domestic hot water heating system. This allows the owner to turn off the boiler completely when a heating load is non-existent. The result is energy savings up to 50% because the new boiler system handles the small summer loads efficiently and eliminates short cycling and cycle losses.

The summer boiler is so efficient that the owner can run it year round for more efficient domestic water heating meaning the building can now be heated with only one boiler in all but the most severe weather promotes more efficient boiler loading for improved energy performance.

Green Distribution Solution

To address the issue of the leaky heating pumps, Metropolitan moved the domestic water heat exchanger and blending valve to floor level for easier inspection and

Pictured is the variable-speed, duplex domestic water booster system with total system capacity of 220 GPM at a system pressure of 95 PSI.

service Workers no longer needed to climb on ladders when servicing the heat exchanger or blending valves. This not only improves staff and contractor safety but reduced maintenance costs overall due to the easier and less expensive service.

One of the biggest benefits is the control over domestic hot water temperatures. No longer will they have spikes or drifts of temperature irregardless of no load or light load conditions. The elimination of spikes in temperature was important given residents were at risk for being injured.

There were benefits as well with the relocation of the heat exchanger and blending valves to the floor. For one, it reduced the safety hazards associated with working on ladders when servicing the heat exchanger or blending valves improving contractor safety. Also with the new pumps, the constant leaking was eliminated.

Realized Energy Savings

With the installation of the “summer boiler”, new heat exchanger and blending valve, the building owner realizes a 20-50% reduction in fuel consumption on any given day depending on load conditions. The entire package combines indirect water heating, condensing water heating and the blending valve function all into one complete system. Metropolitan Industries is the only company currently providing this technology. For more information, contact Matt Brickey at 815-886-9200 ext. 266 for a complete analysis of your system.

June 23, 2010

Famous Chicago Building puts pressure on Green Initiative

The Merchandise Mart located in Chicago.

When the world-renowned Merchandise Mart in Chicago began the task of obtaining LEED-EB certification, it was just the fifth building in Chicago to go “Green”. Adhering to standards set forth by the LEED Green Building Rating System, a voluntary, consensus-based national standard for developing high-performance, sustainable buildings. The Merchandise Mart focused on five key areas of green building strategy: sustainable sites, water efficiency, energy efficiency, materials/resources and indoor environmental quality as set forth by LEED. Such on-going improvements involved reevaluation of capital programs for replacement of windows, roofs, controls, plumbing fixtures, utility meters and lighting.

To better target energy efficiency, just one of the many strategies directed by Merchandise Mart’s Vice President of Engineering Mark J Bettin, P.E. was replacing an outdated domestic water supply system that was a large consumer of energy and an inefficient supplier of water.

Original System

The original system consisted of five pumps ranging in size from 40 hp to 75 hp. The pumps ran at a constant speed intended for the highest demands even during low-flow periods such as during the middle of the night. The system was designed to deliver over 1250 gpm, churned at 290psig, and incorporated pressure reducing valves on the discharge of each pump to maintain a system pressure at 200psig. The five original pumps were oversized by 35HP each, totaling 175 unnecessary horses.

“With recent restroom renovations complete, the water consumption and demand reduced annually by over 35%, resulting in an oversized, inefficient pumping system.

It required large amounts of energy to run and replacing it would help in the buildings’ on going energy reduction efforts and contribute in maintaining the standards of LEED certification,” Bettin said.

According to Merchandise Mart’s Plumbing Foreman, John Geiss, prior to the retro-fit and during heavy usage the domestic water system would see momentary swings in the system as much as 40-PSI at the top end of the system, resulting in noticeable fluctuations at the fixtures and excessive pipe movement.

The Merchandise Mart is the world’s largest commercial building, largest wholesale design center and one of Chicago’s premier international busine

Back View of the Energy-Saving Pump System

ss locations. Encompassing 4.2 million gross square feet, The Mart spans two city blocks and stands 25 stories high. Today, The Merchandise Mart welcomes more than three million visitors each year to its retail shops, boutiques, 11 floors of permanent showrooms for gift, residential, casual and contract furnishings, 10 floors of office space, dozens of trade shows and a myriad of special educational, community and consumer events.

During peak flows, which typically are during a large tradeshow event or during the workweek, demand can reach 750 gallons a minute when up to 20,000 people populate the building during major exhibitions. However, during low flows, as witnessed during the early morning hours, demand can slow to a few gallons a minute. With such a wide range of flows and given the Merchandise Mart’s demanding show schedule where water consumption constantly changes, the new domestic water system would need to match not only extremely high flow demands but also the low flow demands using the least amount of energy necessary.

During the bidding process, quality, service and experience were the criteria important to Bettin when choosing the companies to complete the work.

“We pre-qualified the companies such as engineer KGWW, Metropolitan Industries, Inc., Great Lakes Plumbing and Blaze Electric based on their experience and reputation,” he said.

Chicago-based Great Lakes Plumbing was awarded the design/build contract based on the proposal they submitted. Great Lakes’ Bob DeGuiseppe, project manager, served as the general plumbing contractor and pump and control system manufacturer Metropolitan Industries, Inc. of Romeoville, Ill., designed the new system and pressure reducing zone stations while Blaze Electric of Broadview, Ill. served as the installing electrical contractor and KJWW of Chicago served as Engineer during the project.

The New “Green” System

Metropolitan’s design of the pump system and pressure reducing zone stations was based on two specific goals that included reducing energy costs on day one of start-up; and ensuring enough redundancy to prevent loss of service in the future due to power or mechanical issues.

Working closely with DeGuiseppe, Metropolitan Chicago Sales Manger, Mike Ponx suggested installing a variable-speed system that would reduce energy costs by half due to the system’s ability to precisely match demand using only the minimal amount of energy necessary.

During low flow periods where little or no demand exists, a variable speed system shuts down entirely saving energy and money while four bladder tanks located in two separate locations help maintain pressure, while the system is in shutdown / low flow mode

Front view of the Energy-Saving Pump System

The system supplied was a variable speed, quadraplex booster system using vertical, multi-stage pumps, total system rated at 1000GPM at 200 PSI. The Merchandise Mart’s peak flows are 750 gallons/minute so in a condition where any single pump fails, the system will still be able to handle the load without shut down. To add to the redundancy, there are two separate power feeds divided between the system. Feed A runs three pumps and Feed B runs two pumps. If either feed A or feed B is lost, the building will still have one electrical feed to supply water to the building without interruption or system shutdown. The electrical control system and plumbing design was also configured to one existing pump to operate as a manual stand-by pump to further add redundancy to the building.

The building is divided into four zones to stabilize pressure. At each zone, pressure reducing valves were downsized to maintain each of the zone’s pressure requirements and the four bladder tanks were installed on the 6’’ cold water express risers to sustain pressure when the system shuts off during low flow periods.

Using bladder tanks at the top of the express riser, pressure is stored so the system can shut off during low flow periods. As flow is consumed the pump system will activate and supply water to the building at the desired pressure. Once the demand for water is reduced to a low flow period, the system will shut off once again. Significant energy savings is realized during low flow periods when using variable speed drives and bladder tanks in combination.

During installation of the pumps and controls, interruption of service did not occur to the building said DeGuiseppe. “Since the existing booster system had two independent electrical feeds and the building could not be without water at any time, the electrical controls were built into two sections, which would be mated together during the second phase, he said. DeGuiseppe spilt the new control panel into two sections, Blaze Electric installed the main control section first after disconnecting the first electrical feed, than installed the first two of four pumps using the new controls. Once the first two new pumps were online Blaze Electric removed the old panel and installed the second half of the new control panel, which was designed to mate up to the first section. After that, the remaining two pumps were installed.

Green Savings

The energy savings realized using a variable speed booster system are tremendous. In order to commission the system and measure the savings, meters were installed to measure flow and energy consumption.

Results appeared quickly with the installation of the first two pumps. Energy reductions in the first week were 34%. With completion of all the pumps, the bladder tanks came on line and the system was set for commissioning. Utilizing a system by-pass and real-time flow meter, various loads were created to allow for fine tuning of the drives and staging of pumps. With the removal of the top zone PRV, the system pressure was successfully lowered from 200 to 185. Taking advantage of the bladder tanks, the night-time mode was enabled resulting in the cycling of pumps. Week after week evaluation has shown a reduction in energy by up to 50% with an anticipated annual energy reduction of over 125,000 kwh.

Within a decade, the system will pay for itself entirely on energy-savings and the expected life of this system is over 25-30 years so eventually the system will not only pay the end-user for the cost of the system but it will also pay the costs to replace itself in its lifetime!

Conclusion

According to Geiss, the completion of the retro-fit work improved the overall performance of the system by lowering working pressure and reducing fluctuations throughout the system.

“For the first time we have experienced the most even flow and the best overall PSI performance at the top of the 10th, 18th and 25th floor zones,” he said.

This was accomplished by reducing the size of the valves in the respective zones to “tighten,” up the flow in conjunction to the smooth operation of the variable speed booster system and bladder tanks that feed and assist the entire system as a whole.

“Overall Metropolitan and all parties involved came through with the promise and commitment to a 2-4 psi swing, and an energy savings that will match the Merchandise Mart’s committed effort to LEED providing for a GREENER tomorrow,” said Geiss.