With the end of winter approaching, it is the perfect time to start making plans for next winter by considering updating your business, home, office, or school building’s HVAC and/or boiler system. HVAC system upgrades accounted for 56 of the Energy Efficiency and Conservation Block Grant (EECBG) projects in Minnesota. Over 50 boilers were replaced and 26 projects included the replacement of furnaces in local government or school buildings.
Complaints of uncomfortable working conditions in the buildings are what initiated most of these EECBG-funded HVAC upgrades. The complaints included poor air circulation and ineffective distribution of heat, which were due to the continued use of outdated HVAC equipment.
HVAC and boiler updates in EECBG-funded building retrofits included the following:
- Replacing the energy management system and controls
- Hot water reset controls
- Variable Air Volume (VAV) controls
- Night setback controls
- Economizer controls
- Convert to Direct Digital Controls (DDCs)
- Replace furnaces or boilers with new, better-rated efficiency furnaces or boilers
- Replace water heaters
- Add/replace heat pump
- Replace gas piping
- Install Variable Frequency Drives (VFDs) on motors
- Install occupancy sensors
- Install CO2 sensors
- Replace cooling system with a higher-efficiency system
- Replace air damper
Along with upgrades specific to the HVAC system and boiler efficiency, weatherizing the building can be a great accompaniment to new technology. Pairing the technical upgrades with air sealing, caulking, insulating, and window replacement can make an even bigger difference in energy and cost savings.
Sarah Steinman, CERTs GreenCorps member, was recently certified by the State of Minnesota’s Department of Labor and Industry with a boiler operator license. We spoke with her about the differences between boilers for domestic use and boilers used in larger municipal buildings, boiler safety and maintenance, and the process of retrofitting.
Eliza Leahy: What are the benefits of using a boiler for air heating rather than a furnace? Drawbacks?
Sarah Steinman: In older buildings, boiler systems were often the only practical heating option. Large buildings require the heat to travel long distances, and water retains its temperature better than air. As these large public buildings are being updated, it makes sense to continue using a boiler system, instead of switching to a furnace. Forced air heat also has air-quality concerns that hot water and steam systems do not.
Eliza: Aside from energy savings, what are the differences between older, less energy efficient boilers and newer models?
Sarah: Newer boilers will require less repairs and maintenance, reducing those costs in addition to reducing fuel costs. The size of your boiler may change to address any changes in the building occupancy or size of the building.
Eliza: Are there safety concerns regarding outdated boilers? What are they?
Sarah: While older boilers can certainly operate safely, sometimes older boilers do not receive the necessary maintenance to ensure safe operation. The longer the maintenance is delayed, the boiler incurs more costly damage, which makes it more expensive to repair, and more unsafe to operate. Faulty valves or damaged pipes can result in steam leaks, which is highly hazardous. A pinhole leak of high pressure steam can cut straight through a person. In a worst case scenario, malfunctioning gauges and pumps can result in explosions.
Eliza: What is the process of retrofitting a boiler as opposed to replacing an old boiler with a new one?
Sarah: Replacing a boiler is needed when the pressure vessel, the big part of the boiler where the combustion occurs, is in poor condition and performs poorly.
Instead of boiler replacement, oftentimes partial replacement of systems can be sufficient if the boiler has been properly maintained.
Upgrades of the air, water or fuel systems may be called for, which are a less expensive way to increase efficiency and safety. An updated control system with advanced technology to communicate between systems can dramatically increase the efficiency and safety of a boiler as well.
Eliza: What are the different kinds of boilers available and what are the benefits and drawbacks between them? Are different boilers intended to heat homes rather than commercial or industrial facilities?
Sarah: Boilers in our homes operate under the same principles as larger commercial or industrial boilers, but are much smaller and less complex. Commercial and industrial boiler rooms can be very large and have several boilers in operation. Industrial boilers in factories use steam for many uses in addition to heat.
Some of the uses for steam are in the manufacturing of steel, aluminum, chemicals, paper products, glass, and petroleum refining, in addition to many others.
For local government, they will often just be using boilers to heat the building space and water, which often does not require the larger and more complex boilers of industrial uses.
When you get a new boiler they are already given an efficiency rating. To determine the efficiency of an older boiler, you can perform a simple stack analysis or to get a more accurate number, measure the gas input vs. steam or hot water output.
Eliza: What is the process of boiler maintenance?
Sarah: There are dozens of maintenance procedures that must be done on boilers to ensure proper operation. Checking valves, cut-off switches and gauges for damage or clogs, is something that is done frequently.
A boiler’s fuel system and pressure vessel require periodic cleaning and routine maintenance. Failure to maintain equipment in good working order can result in very inefficient operation and unsafe conditions.
Be sure to keep up with our stories on local government boiler replacements in the following cities: Chisholm, Spicer, Breckenridge, and Hopkins!
Other Local Government Energy Action Heating & Cooling Stories:
- Finlayson Community Center receives boiler, HVAC, and weatherization upgrades
- Energy savings, safety, and comfort: Paynesville City Hall receives new HVAC system
- Discomfort and inefficiency remedied with Breckenridge City Hall boiler replacement
- Hopkins heats up their city’s savings with an energy efficient boiler
- Boilers, controls, and lighting renew Chisholm city buildings
- City of Carlton adopts tried and true energy retrofits
- Building consolidation and upgrades save energy and money in the City of Spicer
About the Local Government Energy Action Series:
This year-long effort tells the stories of nearly 50 Minnesota municipalities, counties, and schools and the tangible results of their energy-saving efforts to inspire others to take their own actions.
Local Government Energy Action is brought to you by the Clean Energy Resource Teams (CERTs) in partnership with the Minnesota Department of Commerce, Division of Energy Resources.
