Choosing the right kW rating for your instantaneous electric hot water heater can be a tricky business. It’s important to get it right, as selecting an inadequate rating can lead to inadequate hot water supply, while selecting a rating that is too high can be a waste of money.
Before we get into how to choose the right kW rating for your electric hot water heater, it’s important to understand what kW is and how it relates to hot water supply. kW stands for kilowatt and is a measure of power used by electrical appliances. In the case of hot water heaters, it is used to measure the rate at which they can heat up cold water into hot water. The higher the kW rating, the faster the heater will be able to heat up cold water into hot water.
Now that we have that out of the way, let’s look at some tips on choosing the right kW rating for your electric hot water heater.
First off, you need to consider your household size and typical usage patterns – do you have multiple people using hot showers or baths in quick succession? If so, you’ll need a higher kW rating than if only one person was using the heater at any given time. Similarly, if there are multiple bathrooms or other fixtures requiring large amounts of hot water in quick succession, you’ll need a higher kW rating as well.
Another factor to take into account is how much cold mains pressure you have coming in – if you have low pressure coming in, then you’ll need a higher kW rating so that more energy can be used to make up for this lack of pressure when heating cold mainswater into hot mainswater quickly enough.
Finally, it’s important to consider any additional features you may want – such as digital temperature control or an anti-scalding feature – as these may require additional wattage and therefore necessitate a higher kW rating than would otherwise be needed.
Once all these factors have been taken into account – household size and usage patterns included – it should give you an idea of what sort of kW rating would suit your needs best. A good rule of thumb is: if there are more than two people using heated showers or baths in quick succession regularly then aim for between 8kW and 10kW; if there are two people using heated showers or baths in quick succession regularly then aim for between 6kW and 8kW; if there’s only one person using heated showers or baths regularly then aim for between 4kW and 6kW; anything below 4kW should suffice for single bathroom households with only occasional use of heated showers/baths.
Hopefully this has given you some insight on how to choose the right kW rating for your instantaneous electric hot water heater! Just remember: get too little power and not enough hot water will be produced; get too much power and money will be wasted on electricity bills!