Saturday, October 15, 2016

Tapping the answer

Time for a lighter topic, something that answers a question I’ve long wondered about: Why do older homes in Britain have separate hot and cold taps at sinks and basins? It turns out there’s a reason for that, as the video above explains. But, is it the same in New Zealand?

The video is by Tom Scott, who’s done several interesting videos I’ve watched. However, because I don’t subscribe to his YouTube Channel, I missed this one when it came out two years ago. Now that I’ve seen it, I finally understand the two taps I’ve seen on British home shows.

One of my favourite TV shows, for a lot of reasons, is “Homes Under the Hammer”, a BBC One series in which people buy residential property at auction, do them up, and sell them on or rent them out. One of the things that’s fascinated me about the show is how pokey so many British homes were before being renovated. That, and the persistence of separate hot and cold taps.

I noticed the same thing about some taps here in New Zealand when I first arrived in this country. It turns out, though, that I was noticing the end of the way things had been as they moved to a new standard.

I don’t know why New Zealand originally used separate taps, though many countries did pre- and post-World War 2. Maybe it was for similar reasons to the UK. When I came to New Zealand in 1995, a great many homes had a low-pressure hot water cylinder heater, while the cold water was mains pressure. Low-pressure systems used a header tank in the attic space or a pressure-limiting valve to regulate pressure.

Nowadays, most hot water heaters are either mains pressure, or else some alternative system at pressure. For example, ours is an LPG (called propane in the USA) continuous-flow hot water heater (this means there’s no stored water—it’s heated on demand, and mains pressure). Nowadays, too, virtually every sink tap in a house from the last ten years or so is a mixer tap.

However, mixers were already common when I arrived in New Zealand: There were special ones for homes with low-pressure hot water heaters to safely mix the mains pressure cold water with low-pressure hot water. We had them in several of our houses before our current one. Our house in Paeroa had a header tank in the attic space, but it’s purpose was to ensure a water supply in case it was interrupted, as apparently had happened from time to time in that rural farming area (in even more rural areas, homes were required to have a rainwater storage tank).

But, even though New Zealand has used mixer taps for many, many years—and they became common long before the UK—there was a big problem with low-pressure hot water heating: Because of the generally smaller hot water cylinders used in the systems, homes often ran out of hot water, especially if it was used by several people. Also, the system usually couldn’t supply hot water to more than one tap at a time at any kind of reasonable pressure.

Mains-pressure hot water systems take care of the problem of being able to supply hot water to more than one tap at a time, as well as having more hot water available. Hardly any home I’ve been in over the past decade didn’t have mixers at every sink, and most had some form of mains pressure hot water.

So, New Zealand was once very much like Britain, with separate hot and cold taps. They may even have originally had similar reasons for it. But New Zealand moved on, and made the switch to mixer taps before the UK did, and almost no one would install them now.

When I watch “Homes Under the Hammer” now, I know why they so often have separate taps. But I’ve also seen some where the renovator installs a modern hot water system AND separate taps—like Tom Scott’s parents. Old habits die hard, I suppose.

Understanding why things are the way they are, and how they got that way, is a good thing, I think. The Internet provides plenty of opportunities to do both.

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