Energy Use
The use of energy to heat buildings in winter and cool buildings in summer is one of the largest bills any business will face in either the form of gas or electricity. All businesses are seeking to reduce these for financial savings and also to lower the carbon footprint of the facility. Listed here are the areas where energy can be wasted, how its wasted, how it can be recovered and an idea of the savings which can be made.
- Hard Water Areas – Hard water is where calcium or magnesium carbonates are dissolved in the water as it passes through the ground on its way to being processed and sent to buildings. Hard water is where the levels of these salts (usually Calcium Carbonate) is higher than 100 parts per million (ppm), in some regions of the country this can be higher than 300ppm such as London the South East and Yorkshire. Hardness can then be deposited in your water systems forming layers on heat transfer surfaces. This can be easily seen in places like kettles or water heaters. These layers of scale can cause a number of problems
- Building-up on heat transfer surfaces blocking the transfer of heat into water, 1mm of scale can reduce efficiency of heat transfer by 5-8% (depending on the efficiency of a system. If there is 5mm of scale the effect would be 25-40%, this is the amount of extra fuel (gas or electricity) to heat the water to the required temperature. The same is true of chilled systems meaning in hard water areas more energy is required to cool the system down.
- Scale build-up on heat transfer surfaces will cause differential heating of those surfaces as the scale build up is not uniform, this will lead to different expansion rates, this will lead to cracking of the heat transfer surface and eventual failure. If this is a boiler, heater or calorifier this can be very expensive and even if the plant is replaced the same thing will happen again at some later point.
- Build-up of scale allows places for bacteria to grow and more importantly the legionella bacteria which can cause legionnaires disease.
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Solutions:
Soften the Incoming water – Softeners |
- Closed Systems – Heating systems – Buildings use boilers to heat them through radiators, air blowers and air-handling units, these are heat transfer areas and can become coated with scale and fouling products from corrosion and bacterial growth. This will make the transfer of heat in the system less efficient meaning energy is wasted either by heating scale, corrosion deposits or worse areas of the system may become blocked and not work at all. See our closed systems page.
- Water Temperature Reductions – Regulations to control the legionella bacteria HSG274 require hot water in buildings to be heated to above 60 degrees C to kill bacteria and to come out of the tap at 50 degrees C or higher after running for 1 minute. These are to prevent the growth of the legionella bacteria in water systems.