How do I fill in the ‘water softeners’ section of the Water Efficiency Calculator in the government’s Code for Sustainable Homes?

The code for sustainable homes is the national standard for the sustainable design and construction of new homes. It aims to reduce carbon emissions and promote higher standards of sustainable design above the current minimum standards set out by the building regulations.  

Here’s a link to the guide to calculating your household figures to comply with the Code for Sustainable Development: 

The section on water softeners (h.) asks for four figures: 

1) Total capacity used per regeneration  

2) Water consumed per regeneration  

3) Average number of regeneration cycles per day  

4) Number of occupants served by the system  

We’ve put together figures which represent an abnormally high usage of water in a very hard water area. 

1) 3.27% 

2) 17 litres 

3) 1.15 regenerations per day 

4) 5 people 

Here’s how we worked out the above answers. 

A Harveys water softener uses 17 litres of water to regenerate. The water softener will regenerate itself when a certain amount of water has passed through it. The amount of water is determined by a gear setting that will be set on installation, based on the local water hardness. 

Using a higher level of hardness than in most English homes, 315 ppm, the gear setting would allow 520 litres of water to pass through the water softener between regenerations. 

This gives us our answers for questions one and two: 

1) 3.27% 

2) 17 litres 

The number of occupants served by the system will vary from house to house but we’ve used a higher figure of five occupants using the water system. 

3) 5 people 

A Harveys water softener only regenerates when a household has used a certain amount of water. We cannot give an average number of regenerations per day without first estimating how quickly the occupants of the house will use water. 

This will depend on some of the other water efficiency figures that you’ll be working out – how many baths and showers, what kind of washing machine, etc. 

We have used another high estimate of 120 litres per person per day. Multiplying this by our example of five people in the household and dividing it by the 520 litres of water the softener softens before regenerating, it allows us to calculate the answer to question three: 

4) 1.15 regenerations per day 

The Water Efficiency Calculator puts all these numbers into a formula and works out how much water is being used beyond the 4% good practice level. 

Our water softeners help you around the home in so many ways. Softened water can prevent limescale build-up in taps, pipes and appliances. Many people think it tastes better than hard water, and it’s much softer on skin. Get in touch with our experts to find out more about our 3 month no obligation trial. Contact us 

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