Spring is coming and it’s time to start thinking about the transition from Heating to Cooling. Now is a good time to start planning the summer heating system maintenance. Most heating systems are down and cold by the 15th of May. That is the best time to get inside that equipment to get all the routine maintenance done, and do a thorough inspection. This is also the very best time to do any major repairs, upgrades or replacements.
Heat exchangers get dirty and need cleaning, soot on the fire side, scale on the water side, and dust on the air side can all act as insulators reducing the coils ability to exchange heat, sending precious energy up the stack. Soot deposits as low as 1/8th of an inch can reduce the efficiency of the heat exchanger by more than 8%, and scale deposits as low as 1/16th of an inch can lower efficiency over 3%, and double that for high mineral content water. Soot and scale both can damage the heat exchanger, especially with high sulfer fuels like oil.
Soot can be an indication of dirty or defective burners, improper fuel to air ratio, or improper combustion. Scale means the water chemistry is off. Now is the time to analyze the water and adjust the chem treatments.
When the system cools down at the end of the season, there will be condensate in the flue, and that can lead to corrosion. Water and the sulfer oxide components of the soot can create sulfuric acids that eat away at expensive components of the heat exchanger and lead to damage and potential dangers of escaping flue gases.
Burners need cleaning and adjusting. Fuel to air ratios need adjusting. Draft and combustion can be measured and adjustments made to ensure that the system is ready come Sept. Getting it done early will give time to respond to any serious issues that might be uncovered in the inspection. Doing it early enough ensures that evening temperatures will still be cool enough that you can trick the system into firing through a full cycle to ensure it is operating properly. High summer is not the best time to be firing up your boilers to make adjustments.
So dig up that equipment maintenance manual and dust off that copy of ASHRAE Standard 180, break out that toolbox, and get a good early start on that summer maintenance program.
By Clifford Babson, CEM, CMVP, CEA, LEED AP, BOC instructor.