Why is a secondary return system used in a hot water system?

Secondary hot water returns are generally used in domestic hot water applications where the point of usage (i.e. taps) are a distance away from the hot water cylinder. They are used to remove the need to draw off a large quantity of cool water, ( left in the pipe run), before hot water actually reaches the tap.

What is a secondary circulation pump?

A secondary pump usually refers to a ring of pipe for the hot water supply with a pump to circulate the water around the pipe. When a tap is opened the hot water is “on demand”. The pump is required when the water in the cylinder is up to temperature.

What is hot water draw off?

When the boiler is running, hot water flows continuously around the primary circuit. As the pipes of the heat exchanger warm up, so does the water in the cylinder. This can then be drawn off from the top of the cylinder to supply the hot taps around your house (the secondary circuit).

What is a secondary circuit in plumbing?

An assembly of water fittings in which water circulates in supply pipes or distributing pipes of a hot water storage system.

What is the purpose of secondary circulation?

Secondary circulation helps reduce the delay from turning on your hot tap to actually getting the hot water. This is often beneficial for larger installations with longer pipe runs. Water sitting in the pipes firstly needs to be drawn off, (and typically wasted!)

Which hot water storage system requires the most pipework and fittings?

Question 12: Which one of the following hot water storage systems installations is likely to require the most pipework and fittings? The right answer is Indirect Hot Water System (D), as you selected.

How does secondary circulation work?

A secondary hot water circuit circulates a loop of hot water around the property, in close proximity to the outlets. Such as the kitchen and bathrooms. Therefore, whenever a tap is turned on, the hot water is almost instantaneous, coming from the nearby loop.

What is an example of secondary circulation?

The portion of a building required for access to some subdivision of space (whether bounded by walls or not) that does not serve all occupants on a floor, or that is not defined as primary circulation. Examples of secondary circulation area are aisles, corridors, and hallways.

When to use secondary circulation for hot water?

Secondary Circulation to ensure hot water is available immediately the tap is turned on. If there is a significant delay from turning on your hot tap to actually getting hot water, then secondary circulation should be a considered.

How does a secondary water return system work?

Secondary systems incorporate an additional return pipe after the furthest draw off point from the cylinder, smaller than the domestic hot water supply pipe. This hot water is pumped around the system, ensuring that whenever you turn on a tap, the hot water is almost instantaneous and the supply is constant, delivering hot water as needed.

Why is hot water drawn off after using the tap?

Furthermore, the newly replenished hot water in the pipe will again cool down, only to be drawn off again the next time the tap is used. This is inefficient and encourages water wastage; a volume of water is heated, allowed to cool and then drawn off.

Can a secondary circulation circuit be retro fitted?

Hot water secondary circulation circuits are best designed into new hot water systems where required, but can generally be retro-fitted to depending on the existing pipe layout and design. It’s important for any exposed pipe work to be well insulated in-order to minimise any unwanted heat loss due to…

How does a secondary circulation hot water system work?

This can be overcome by installing a secondary hot water circuit, which works by circulating hot water around the property close to the outlets in the bathrooms and kitchen. This hot water is pumped around the system ensuring that whenever you turn on a tap, the hot water is almost instantaneous.

When do you need to use secondary circulation?

If there is a significant delay from turning on your hot tap to actually getting hot water, then secondary circulation should be a considered. This is often necessary in larger installations with longer pipe runs. The water contained within the pipes needs to be drawn off, (and typically wasted!) before the hot water gets to the outlet.