Getting to know how recovery time and the size of the cylinder can work in tandem to provide the best hot water cylinder solution for your customer is a valuable skillset. George Linder, product manager at Heatrae Sadia, explains the basics of what you need to know:
It is not uncommon for recovery time and the size of a cylinder to be confused as being the same thing. Naturally, many customers will believe that bigger is better. While the size will determine how many litres of water can be stored at a time, it is the recovery time that ensures once depleted the hot water can be replenished.
The recovery time of a cylinder is calculated by the kW rating, the greater the rating, the quicker the cylinder is at replenishing the hot water. Opting for a large cylinder with a low kW rating will mean that once the hot water has been used the homeowner could be waiting hours for more hot water, so you need to get it right based on their usage.
To put this in perspective, a two-person household will use roughly 84-litres of hot water per day given that a seven-minute shower, at six litres per minute, approximately uses 42 litres of hot water. So, using a 125 litre Megaflo ECO hot water cylinder, would cater to this demand and some extra to account for other hot water tap outlets. Once the hot water has been used up, the expected recovery period for 70% of the volume for this cylinder is approximately 30 minutes, when the heat input is approximately 12kW.
If a larger household wishes to run a bath and multiple showers at the same time, then a bigger cylinder would be required. This is why installers should not only ask about the household’s lifestyle when it comes to the use of hot water, but also explain the reasoning behind the importance of size and recovery time when selecting the best cylinder for the household’s needs.
For more information on the Heatrae Sadia range of cylinders and hot water solutions, visit: https://www.heatraesadia.com/products/cylinders-and-hot-water.