Question: Some suppliers mention that they do not recommend that harvested rainwater is used for showers or dishwashers. What is the JFC view on this?

Answer: The uses for the harvested rainwater is a common question and sometimes poor advice can be given from suppliers. Normally rainwater is used only in toilets, washing machines and garden taps. For use in showers UV sterilisers are sometimes used to kill any bacteria that may be present in the water and are installed to improve the water quality. UV sterilisers will not sufficiently treat the water to a quality suitable for human consumption and therefore rainwater is not recommended for dishwashers, kitchen taps etc. in this instance.

If the water is to be used throughout the house JFC recommend that a specific treatment system be installed to bring the water to the required standard. JFC have partnered with Galway Water Solutions who can provide a customised treatment system for each client with a guarantee on water quality. This system costs approximately €2,000 - €2,500 depending on specification and can be installed directly after the JFC rainwater harvesting system to allow the water be used throughout the house including drinking.

Question: Some suppliers recommend a smaller tank size than JFC, why is this? Also, are there set guidelines on estimating the tank size or does each supplier calculate their own?

Answer:Some suppliers will size a tank based on what they can offer and commonly undersize it to gain a cost advantage. At present, there are no set guidelines in sizing a rainwater harvesting tank but JFC size the system based on the roof area, rainfall data and water usage. JFC also size a tank for a 21 day retention period, so that if there is a dry spell of weather, you still have a reserve of water to meet your needs. If you want to size a system for your house, please do not hesitate to contact us.

Question: What are the advantages of the JFC mains water back-up system vis-à-vis other systems?

Answer: Standard mains water backup systems fill the rainwater tank to a preset level (e.g. 25%) with mains water. This means that your tank is always filled with 25% of mains water and therefore the system cannot hold 100% rainwater and will be inefficient and undersized. The JFC system changes over from rainwater to mains water at the pump (located in the a garage / pump house) and therefore mains water never enters the tank and it will operate at 100% efficiency. In this way, you also minimize water charges which have been rising consistently in recent years.