Efficient Upgrade – Condensing Boilers

To increase a property’s tenant appeal and market value, building owners and managers often pursue a combination of architectural improvements and mechanical system upgrades.
When it came time for the managers of 250 Apollo Drive in Chelmsford to embark on base building upgrades, they chose to partner with Chapman. The work performed at Apollo Drive included a variety of improvements, not least of which was a complete refurbishment of the existing base building boiler plant, which will reduce the building’s operation and maintenance costs as well as improve the system’s performance.

Typical HVAC systems have a lifespan of 20-25 years. Over time they become less efficient and require more maintenance. To remedy this, older devices can now be replaced with streamlined, efficient systems that are far more effective at accommodating tenants’ varying needs. What once may have required a bank of eight boilers to heat a 144,000 sf building can now be done with just three modern replacements.

At the Apollo Drive property, Chapman has completed the installation of three Cleaver-Brooks high-efficiency modulating condensing boilers with stainless steel heat exchangers. The boiler replacement included the addition of VFDs (variable frequency drives) for the circulation pumps and new FPTs (fan powered terminal boxes) for distribution.

What makes these new boilers so efficient? Typical oil and gas burners have only one firing output that is sized for the coldest day of the year. Modulating boilers, however, are responsive to outside temperatures and have the ability to ramp hot water production up and down to match the demand of the building’s heat loss. Additionally, in a conventional boiler the hot exhaust gases that are produced are simply vented to the flue, whereas condensing boilers capture the resultant heat from combustion and return it to the system. The combination of modulating response and efficient fuel combustion substantially increases the efficiency of these boilers.

The Cleaver-Brooks system was recommended by RDK Engineers, who engineered the system to maximize efficiency as well as to take advantage of available energy credit rebates. The rebates ultimately totaled roughly 25% of the system cost.

Although condensing boilers have been in use in Europe for more than a decade, they’ve only recently begun to gain ground in the US. If you are interested in learning more about this rapidly advancing technology while earning AIA and LEED CMP CEUs, consider attending the free in-depth lecture Chapman is hosting on April 27th.

Chapman’s Apollo Drive team includes Executive Project Manager George Dyroff, Project Manager Tony Brown, Assistant Project Manager Chris Draper and Senior Supervisor Mike Beaudry.

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