Turndown and Low-Emission Conversion of Four Cleaver-Brooks CB 200-700-15st Boilers for a 300+ Unit Apartment Complex
By Arris Poulos, Project Manager | August 21, 2026
Miller Proctor Nickolas, Inc. (“MPN”) recently completed a high turndown and low-emission conversion on four Cleaver-Brooks CB 200-700-15st boilers at a 300+ unit apartment complex, modernizing the combustion systems and controls to improve efficiency, reduce emissions, and enhance overall plant operation.
The project combined combustion upgrades, controls modernization, and plant-wide integration to transform an aging boiler room into a more efficient system while maximizing the use of the existing equipment.
High Turndown Combustion Upgrade
The first phase of the project focused on upgrading the combustion system to support high turndown operation and cleaner combustion.
MPN’s factory-certified technicians opened the front head of each boiler and modified the inner and outer doors to install a new flue gas recirculation (FGR) valve. The FGR system reintroduces a portion of the exhaust gases back into the combustion process, helping reduce emissions and maintain stable burner performance.
To accommodate the upgrade, our team:
- Upsized blower motors from 40 HP to 50 HP
- Added new high-temperature door insulation
- Replaced burner housings with high turndown configurations
- Installed new burners designed for cleaner combustion and improved operation
These modifications improved combustion performance across a much wider operating range.
Controls Modernization
To complement the combustion upgrades, MPN completed a full controls modernization.
The existing control package, including jackshafts, stack dampers, electrical controls, and water controls, was removed and replaced with the Cleaver-Brooks Hawk 4000 control system improving the system’s operational capability.
Additional upgrades included:
- New Cleaver-Brooks stack dampers
- Custom-fabricated spool pieces for proper sealing and fit-up
- New variable speed drives (VSDs) on blower motors
The VSDs provide a soft-start function and more precise control of blower operation, reducing electrical demand and mechanical stress on equipment.
Centralized Plant Control
As part of the modernization effort, MPN also installed a master control panel for the boiler plant.
The master panel allows operators to manage all four boilers from a single location, creating better staging, sequencing, and overall plant operation.
A Complete Boiler Plant Upgrade
This project highlights MPN's ability to perform complex boiler plant retrofits that combine:
- High turndown burner conversions
- Low-emission combustion upgrades
- FGR integration
- Burner and blower modifications
- Controls modernization
- VSD installation
- Master panel integration
By combining mechanical expertise with advanced combustion and controls technology, MPN delivered a fully integrated upgrade that improved the performance and operation of all four boilers.
The job allowed the apartment complex become eligible for rebates equal to 50% of the project’s total cost and adhere to Local Law 97 requirements, avoiding substantial penalties.
Contact MPN today or
Call (914) 332-0099 to schedule a site visit
Learn how we can help improve the efficiency, reliability, and performance of your boiler plant.