In New Zealand, the choice of hot water systems can significantly influence the performance of household showers. These systems can be categorized based on their operating pressure and their management of that pressure.
Low Pressure Unequal Systems:
- Overview: These operate at a low pressure, often supplied by a header tank in the ceiling space. The term “unequal” indicates that the cold water pressure (typically from street mains) is higher than the hot water pressure from the header tank. While they are less prone to leaks, they may deliver water at a slower rate.
- Shower Performance: The low pressure affects the flow rate of hot water, which can be noticeably slow. When combined with the higher-pressure cold water, this can result in inconsistent flow. Additionally, sudden uses of water elsewhere in the house (like flushing a toilet) can cause abrupt temperature changes during a shower.
Low Pressure Equal Systems:
- Overview: Like unequal systems, these also operate at low pressure but both hot and cold water are supplied at the same pressure, usually from a header tank. This ensures equal flow rates, making them an improvement over the unequal systems.
- Shower Performance: The balanced pressure ensures a consistent mix of hot and cold water, reducing sudden temperature changes. However, the overall flow can still be slower compared to high-pressure systems, potentially affecting the shower experience.
High Pressure Hot Water Systems:
- Overview: These systems operate at mains pressure, delivering water more swiftly. They usually use a cylinder designed to handle the increased pressure and provide a consistent flow rate, ideal for homes with multiple bathrooms.
- Shower Performance: Showers benefit from a robust, steady stream, enhancing the overall experience. Modern high-pressure systems, especially with thermostatic mixing valves, maintain consistent temperatures even with simultaneous use of other taps. They can generally accommodate multiple showers without a significant drop in performance.
The type of hot water system in a house can greatly shape the shower experience. High-pressure systems, due to their flow rate and temperature stability, are often preferred for optimal shower performance. However, for homes with existing low-pressure infrastructure, considering factors like the showerhead type can also influence the experience. With advancements in technology, high-pressure systems have become more common in New Zealand’s newer homes and renovations.