7 steps to increase boiler efficiency

One of the easiest ways for a company to reduce operating expenses is to increase boiler efficiency. A good place to start to reduce your bills is to see how recently you have had your boiler serviced and how efficient your boiler is.

Before we get to our efficiency tips, which also help you to increase the lifetime of the boiler,In the boiler, we must understand the efficiency of the boiler. Most of the heat lost in your boiler is in the flue or in the boiler water. The aim is to create conditions that generate as little flue gas as possible at the lowest possible temperature. This results in higher boiler efficiency.

Whether you rent or own a boiler, you need to save money. Here are 7 simple tips to help make your boiler system more efficient and save money on your monthly bills:

1. Increases boiler efficiency: lowers stack temperature

   Lowering stack temperatures can be as simple as a day/night delay. This reduces the operating pressure of steam boilers and the operating temperature of hydronic boilers when they are idle at night or on mild days.

2. Install an economiser

   An economiser uses the wasted hot flue gas to heat the feedwater on its way to the boiler. If your steam boiler does not have an economiser or your economiser is not working, this should be the first priority. Economisers save fuel and avoid the harmful effects of feeding cold water to the boiler.

3. Tune the burner regularly

   Another common problem that occurs when it comes to boiler efficiency is not getting the right amount of air. For proper combustion of the fuel inside the boiler, a certain amount of oxygen is required. If there is too little air, the carbon in the fuel will oxidise and produce carbon monoxide. This causes less heat to be released because the fuel does not burn completely, which reduces the efficiency of fuel use.

   Low air generates soot, smoke and carbon monoxide, all of which are very dangerous. Too much air also reduces efficiency. The extra air enters cold and sends the stack hot, wasting heat.

   An optimal process provides sufficient air for the fuel to burn safely. To achieve this, we measure the required amount of air with an O2 probe. We insert the probe into the chimney while adjusting the burner for optimum boiler efficiency.

   However, in some installations, the temperature of the air entering the burner varies with the seasons. This requires the burner to be tuned more frequently for maximum savings.

4. Install a frequency inverter

   There are not many burner fans or pumps today without VFDs. However, if you haven't heard of VFDs or have a system that doesn't use them, take note. The incredible energy savings come from a concept known as affinity laws for pumps and fans. If your system has a fan or circulating pump controlled by a regulator or valve, your system is wasting electricity at partial loads. A VFD allows your system to control the flow with the fan or pump speed, and that's where the magic happens.

5. Increase boiler efficiency: insulate your valves

   Many plants remove valve insulation in the boiler room for maintenance and never replace it because it is a nuisance. However, exposing these large valves to air causes a large heat loss and can make the boiler room unbearably hot.

6. Cleaning the chimney

   Over time, soot can build up on the fire side of the boiler tubes, especially with older equipment. This layer of soot acts as an insulator, reducing the rate of heat transfer and increasing fuel use. Due to the lower heat transfer rate, hot gases pass through without transferring heat to the water, which increases the stack temperature. Cleaning and inspection of the boiler tubes as part of regular boiler maintenance ensures that soot is kept to a minimum. This improves the overall efficiency of the boiler.

7. Preheating the combustion air

   The burner must heat the incoming combustion air with the flame. If the air introduced into the burner is warmer, less fuel is needed to produce the same amount of steam in the boiler. A modest 5°C increase in fresh air temperature can save 1% on the fuel bill. If you run large boilers all day long, this can really add up even with our historically low gas prices. In some cases, an air preheater can pay for itself in less than a year.

If you are interested in finding out more about how to increase boiler efficiency and reduce costs, we invite you to get to know the checklist to ensure the maintenance of industrial boilers, as well as the steps to optimise steam trap operation.

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