As fuel costs continue to rise, there is great interest and need to provide things like hot water and heat as efficiently as possible. High efficiency condensing boilers are one way to accomplish this. We’ll discuss more details on this type of product.
With a conventional boiler, fuel is burned and the hot gases which are produced get passed through a heat exchanger. This is where much of the heat gets transferred to water and raises its temperature.
A key component produced during the combustion process is water vapor or steam. A high efficiency condensing boiler is able to extract additional heat from the waste gases in the combustion process by condensing the water vapor and turning it into liquid water. It recovers the latent heat of the steam.
The improvements in energy efficiency can be as a high as 10 to 12% versus a conventional boiler. Its effectiveness largely depends on the temperature of the water which gets returned to the boiler. However the efficiency is always at least as high as a conventional boiler.
Since the condensate which gets produced in this process is slightly acidic, the choice of materials used in a high efficiency condensate boiler is very important. For high temperature applications, the typical materials used are aluminum alloys and stainless steel. And for lower temperature applications, plastics such as PVC and polypropylene are more commonly used.
Since condensate is used in these types of boilers, the installation of a heat exchanger condensate draining system is required. High efficiency condensate boilers are used extensively in Europe but they are now becoming more popular in North America as well.
Their extensive use in Europe has been assisted by strong government regulations and incentives. This is particularly true in the United Kingdom. And in the US, there are Federal Tax Credits for the installation of a condensing boiler and some additional rebates are available from power companies in certain states. Many existing boilers are being retrofitted with condensing equipment in order to achieve the desired improvements.
The manufacturers of high efficiency condensing boilers claim that up to 98% thermal efficiency can be achieved versus 70 to 80% with conventional boiler designs. Most models average around 90% efficiency. In the UK, these types of boilers have received a SEDBUK Bank A efficiency rating and in North America, they normally receive an Eco Logo and/or the Energy Star designation, as well as AHRI certification.