| What is a Cold Water Accumulator? | | | | exterior installation such as in an open garage or |
| Cold water accumulators are an efficient, energy | | | | shed. There are no drainage requirements and no |
| saving way to deal with the problem of low incoming | | | | power supply is needed for an accumulator so the |
| water pressure to your heating system, and the | | | | only concern is the pipe work that will need to run |
| simplest way to think of them is as a large water | | | | from the accumulator to the house. Depending on |
| storage tank which adds water, topping up the | | | | the size and shape of a cold water accumulator it |
| heating system when the demand is greatest. | | | | may or may not be suitable for horizontal installation, |
| They consist of a steel tank with two chambers | | | | say in a loft. Make sure you are buying the correct |
| separated by a diaphragm. One side of the | | | | model for your needs. |
| diaphragm is sealed and pressurized with compressed | | | | What are the regulations regarding Cold Water |
| air; the other side is open to the water system. | | | | Accumulators? |
| When you open an outlet such as a bathroom tap, | | | | A cold water accumulator can be installed anywhere |
| water initially flows from the accumulator until the | | | | on the mains supply entering the property and there |
| pressure drops enough for the pump to turn on. As | | | | must be a check valve installed on the main supply. |
| the pump runs it provides the water flow required by | | | | A 3.5 bar pressure reducing valve will also have to be |
| the open outlet. When the outlet is switched off | | | | fitted if the pressure is likely to rise above 5 bar. |
| the pump will continue to run until the cold water | | | | The air pressure inside an accumulator is set at 2 bar |
| accumulator has re-pressurized itself to the pressure | | | | but may need adjusting so that it is between 1 – |
| that the setting on the pump will shut off at. | | | | 1.5 bar below the mains pressure. The minimum this |
| How much will a Cold Water Accumulator increase | | | | can be set to is 0.5 bar but this will require consulting |
| my water pressure by? | | | | the manufacturer. |
| A common misconception. Accumulators do not | | | | The lower the mains pressure is, the less water that |
| increase water pressure. They simply allow the | | | | may be stored in the accumulator, so always |
| system to work at its maximum pressure capability. | | | | remember to oversize the accumulator by at least |
| Each hot water system has a standing pressure and | | | | one clear size more than your unvented cylinder or |
| a working pressure. Just as it sounds, "standing | | | | flow rate requirements. |
| pressure" is the pressure that exists when no outlets | | | | I have a shared water main. Can I still install a Cold |
| are being used and the water is at rest. This | | | | Water Accumulator? |
| pressure will drop to "working pressure" when taps | | | | Yes. Cold water accumulators can be installed on |
| or showers are being used. | | | | 15mm (small bore) or even on shared main supplies |
| A cold water accumulator works by supplementing | | | | as long as you carry out pressure and flow tests and |
| the flow of water when the system has open | | | | oversize the accumulator to not only meet but |
| outlets, thus raising the flow back up to standing | | | | exceed the expected demand. |
| pressure even though outlets are open and it would | | | | Is there anything else I should know about Cold |
| normally be under working pressure. When the | | | | Water Accumulators? |
| outlets are closed, the accumulator shuts off the | | | | A correctly sized accumulator will allow almost any |
| additional flow until it is needed again. | | | | number of baths or showers to be taken at the |
| Can I use a Cold Water Accumulator with my | | | | same time, regardless of the incoming main flow rate, |
| existing Combi Boiler? | | | | and will keep working even if the mains are turned |
| Yes. Combination boilers with a poor rate of flow | | | | off, irrespective of the mains water pressure |
| can be used in conjunction with a cold water | | | | Requiring no power supply, generating no noise, |
| accumulator, allowing the boiler to run at its max rate | | | | consuming no energy and needing no ongoing |
| of flow and not be interrupted if a second outlet is | | | | maintenance, a cold water accumulator is the most |
| switched on during a shower. | | | | economical and environmentally friendly possible |
| Where can I install a Cold Water Accumulator? | | | | option for households suffering from low mains |
| Accumulators come in many different sizes and | | | | pressure. |
| styles. Specially designed models are suitable for | | | | |