Many may think that a hot water cylinder can easily run out of hot water, causing the cold wait until it’s hot again. But Mr Central Heating knows, that this isn’t always the case. If the cylinder is the correct size for the usage of that household, it should never run out but sometimes circumstances mean that this usage can spike. What can be done when granny comes to live at yours, or you add a bathroom in an extension?
Hot water cylinders are used to store water and you may notice there are two main types of cylinder, these being either indirect hot water cylinders or direct hot water cylinders. The water in a direct hot water cylinder uses immersion heaters within the cylinder itself to heat the water, some have multiple to ensure optimum performance. An indirect hot water cylinder is reliant on an external appliance such as a boiler to generate the heated water. Interestingly, some indirect cylinders have an immersion heater installed too for additional heat that may be required. These are usually used as a backup or boost function.
You may also come across the terms, vented cylinder and unvented cylinder. The difference between the two is simple, unvented hot water cylinders are connected directly to the mains water supply, whereas vented cylinders are connected to a cold water tank and get their water supply from this instead. You will normally find the cold water storage tank in the loft of your home. Whereas you often find the hot water cylinder in your airing cupboard.
It can be daunting when considering the right size hot water cylinder for your home, but it is essential to ensure that your hot water demands are being met. A hot water storage cylinder that is too large will create sitting water that isn’t being used and will waste a lot of energy heating it up. A cylinder that is too small won’t be able to meet the needs for hot water in your home, creating a few chilly showers as the boiler will need to reheat the water. The capacity of a cylinder will change depending on whether it’s being heated by an indirect heat source (e.g. a boiler) or directly. The cylinder capacity is always measured in litres, which can be confusing when thinking in terms of showers or washing up loads. However, the easiest way to work out what size and capacity you’ll need is by looking at the number of bedrooms, bathrooms and showers you have. You can find lots of information online and usage calculators, suggesting sizes based on the litres of hot water you're likely to use if you’re concerned. The good news is that we stock a range of sizes to suit all your needs.
So, perhaps you have the correct size hot water tanks for your usage, but you add an ensuite or downstairs shower room adding to demand and you’re concerned it won’t be able to cope. The solution would be to temper your water. Essentially, tempering means raising the temperature of water in the cylinder, mixing it with a tempering valve to achieve a lower water temperature output, thus producing more hot water from the same size cylinder.
Generally, cylinders store water at around 60-65°C. If this was increased to 70°C, you would produce more water delivered at 55-60°C as the valve mixes both hot and cold water, which provides an increase in the capacity of the cylinder. Mixing the hot water with cold means that less hot water is drawn, increasing its capacity and the amount of usable hot water for the home for longer.
The domestic hot water cylinder can meet household hot water demands from multiple places, even if your demand on your central heating system increases, providing a great solution in comparison to other products on the market which can’t continue to work under the pressure of more demand. Take a look at our water storage range for a whole host of options available.