For many commercial buildings and large manufacturing facilities, having a steady supply of hot water is essential. Schools, hospitals, and processing plants may use several thousand gallons to several million gallons of water per day based on their specific needs. Facility managers will work with engineers to design the most cost-effective hot water systems for the building that increase efficiency while decreasing waste and costs of operation. Two of the most talked about hot water systems today are condensing and non-condensing boilers.
Traditional Non-Condensing Boilers
For decades, companies have relied on non-condensing boilers to supply the right amount of hot water to buildings and equipment. These systems will normally have two types of fuel sources. The main fuel source will be natural gas and the second fuel source will consist of fuel oil. The system is designed to take the air from the room into an intake to provide combustion and heat the water or create steam that is then used throughout the building. Exhaust gases created during combustion are allowed to escape through the flue stack. There are several different non-condensing boiler designs for commercial operations:
- Water tube: where tubes will contain water and steam as the combustible fuel flows around the tube. The tubes are connected to different drums to create the furnace and convection areas. There are also flexible water tube systems.
- Fire tube: where the combustion gases and furnace flame are inside tubes located in a cylindrical vessel that holds the water and steam.
- Electrical: where electricity is the main energy source to heat the water, eliminating the need for combustion components inside the boiler or flue stacks to vent harmful exhaust.
- The one major factor of non-condensing boilers is that it should not condense the flue gases or have the condensate reach the pressure vessel to cause corrosion. This problem usually occurs when the flue gases reach the dew point when cooling, which can occur in colder climates and during cooler seasons. This issue can be reduced by having a minimal return water temperature of 150 degrees.
Condensing Boilers
Condensing boilers have recently been introduced to the market to provide more efficient thermal capabilities. The basic system design is that the boiler is completely sealed as the air used during the combustion process is drawn in through the flue from outside. The created flue gases are not vented out. They are allowed to change and condense on the surface of the heat exchanger as the heat in the condensate is recovered and used. Then the condensate liquid is drained into a waste pipe.
Condensing boilers have a lower return water temperature of 110 degrees, making them more efficient than non-condensing boilers. These systems also maintain their high efficiency throughout the changing seasons. The drawback of condensing boilers is that they currently have a limited heating capacity. So certain buildings and facility operations may not be able to obtain the full benefits of these systems.
Deciding on the right type of boilers will be based on a number of factors including your operations, the configuration of system components, boiler usage, the size of the system, the climate and the outdoor air temperatures. By evaluating your operations, you will be able to purchase or retrofit a boiler system that will increase the capabilities of your equipment while lowering your energy costs.
At A. Messe Supply, we have everything you need to ensure your condensing or non-condensing boilers are running smoothly. Call today to order relief valves, boiler gauges, boiler cleaner, HVAC brushes, or anything else you need for your Chicago facility!