It is both an art and a science to ensure that commercial boiler systems are operating at maximum efficiency. Are you committing any of these boiler faux paus?
Hastily Adjusting Boiler During Startup
Upon the initial set up of a new boiler, the air to fuel ratio should be tested and adjusted to make sure the system is set to operate at maximum efficiency. A general rule of thumb is to let boilers run for about 20 minutes before adjusting any controls, to give the boiler flame enough time to stabilize and reach accurate readings. If a boiler is installed in during the summer (or warmer temperatures) it is also advisable to recheck the readings during a cold weather season, when the hydronic loop won’t prematurely shut off upon reaching temperature.
Reusing Improper Flue and Other Components
A common method for cutting costs when installing a new commercial boiler is to reuse the existing components in the rest of the system. It is extremely important for both performance and safety reasons to examine each piece of equipment if going this route.
- Flue: Be sure to double check all joints, look for signs of possible corrosion, and confirm that the stack is the correct category for the boiler so there are no flue gas leaks.
- Expansion tank: Verify that the size of the tank is acceptable for the size of the boiler system being installed.
- Pumps: ASHRAE recommends that any pipe mounted pumps should be replaced after 10 years. Base mounted pumps have a 20-year maximum life expectancy.
- Air Vents: It is recommended to replace all air vents when installing a new hydronic boiler after draining the system. Besides impeding flow, undetected air pockets may rust the piping in the system.
A Boiler Room that is Too Cold
New condensing boilers emit less heat loss into a boiler room. Therefore, if you are replacing a boiler with a new, condensing one the boiler room that used to be a stable temperature may now require additional heat to ensure that boiler room equipment functions properly. As with boiler startup, it is a good idea to double check the temperature of the boiler room during cold seasons to ensure it is adequate.
Not Following the 7 Times Rule
The 7 times rule states that the cross section area of the largest common vent shall not exceed seven times the area of the smallest draft hood outlet. For this reason, when a boiler is replaced, the water heater flue should generally be replaced to accommodate this sizing guideline. Even if the chimney flue is reused, many times the water flue should not be.
Interested in having your boiler system examined by on of our engineers? Contact a UEP specialist today for a boiler room assessment!
