I’ve just bought a house. It has a big spa style bath. We were told to buy as big a boiler as we can to fill it up i a timely fashion. I saw in B&Q gas boilers go up to 24 litres per minute. The guy today told us to get an electric one but I remember my dad tanning my hide when I was a lad for turning on the electric immersion heater at home because they cost a fortune to run. I looked on the internet about the relative costs of running each. There’s nothing about Taiwan, mostly about America, in which it seems that natural gas is about a third of the cost of electric.
Anyone have any first hand experience of buying a boiler? Done any sums about how much it’s going to cost to run?
A gas boiler can deliver heat faster than an electric boiler (which is limited to ~1.5Kw if plugged into a standard 110V socket, 3Kw at 220V). I think gas works out at about NT$2/KWh, while electricity is NT$4 or 5/Kwh. The catch is that most gas boilers here are half-assed shite made in China, with way too much heat going out the flue, so in practice they’ll work out about the same in terms of running cost. Anyway, as HH said, you need to make sure you actually have a gas supply.
If you do mean ‘house’ rather than apartment, I would seriously consider a solar water heater, especially if you live down south.
First electric boiler I bought lasted only 5 years.
Its replacement has lasted about 5 years so far.
We live in a wooden house, so I’m a lot more comfortable with an electric boiler.
But if we lived in an apartment, and had natural gas connected, I’d probably go for the gas boiler.
It would definitely take up less space (and it sounds like you need a big one), and it would probably have a longer life expectancy, too.
As far as running costs are concerned, I don’t think the electric boiler is that expensive - not compared to running an AC, anyway.
(Ours runs off 220V.)
Nevertheless, I don’t see any reason why the info you got about American boilers would not be generally applicable here. I mean, the relative costs of electricity vs. natural gas are probably similar.
As Finley said, electric on-demand heaters can’t deliver enough power. If you go electric, you will need an insulated hot water storage tank (with a capacity of about half the size of your bath) plus associated plumbing. I think that’s what you mean by immersion heater.
As for gas, even at 24 liters per minute, it’s still going to take 40 minutes to fill up a 1 cubic meter spa-style bath. Depends what you think is a “reasonable” time frame. Piped gas is a must - if you have to buy a new tank of gas every time you have a bath, then that’s gonna get old pretty quickly.
If you use a “continuous-flow water heater” (Durchlauferhitzer) hope my translation is correct you’ll be fine using the 220V type. I used one of those in Berlin and it was capable of delivering hot water for a big bathtub.
No water storage needed for those either.
The advantage over gas is, that you can put the electric heater close to the location where you’ll be using the water. If you can’t install the gas heater close to the kitchen and bathroom, it might be better using an electric heater, otherwise I’d go with gas.
The problem is not so much the couple of showers a day. It’s more the quick warm wash for things like the frying pan you want to use now, the cup, your hands etc. If the heater is far away from the kitchen and bathroom each time you want a little hot water it will fill up the whole water-pipe first.
My kitchen is about ten meters of pipe away from the gas heater and I am considering getting in addition to gas a continuous-flow water heater either 110V or 220V.
[quote=“Hamletintaiwan”]If you use a “continuous-flow water heater” (Durchlauferhitzer) hope my translation is correct you’ll be fine using the 220V type. I used one of those in Berlin and it was capable of delivering hot water for a big bathtub.
No water storage needed for those either.
The advantage over gas is, that you can put the electric heater close to the location where you’ll be using the water. If you can’t install the gas heater close to the kitchen and bathroom, it might be better using an electric heater, otherwise I’d go with gas.
The problem is not so much the couple of showers a day. It’s more the quick warm wash for things like the frying pan you want to use now, the cup, your hands etc. If the heater is far away from the kitchen and bathroom each time you want a little hot water it will fill up the whole water-pipe first.
My kitchen is about ten meters of pipe away from the gas heater and I am considering getting in addition to gas a continuous-flow water heater either 110V or 220V.[/quote]
That thing draws a massive 120 amps even at 240 volts and it still only delivers 15 liters per minute. Regular house wiring just can’t cope with that kind of load.
[quote=“monkey”][quote=“Hamletintaiwan”]If you use a “continuous-flow water heater” (Durchlauferhitzer) hope my translation is correct you’ll be fine using the 220V type. I used one of those in Berlin and it was capable of delivering hot water for a big bathtub.
No water storage needed for those either.
The advantage over gas is, that you can put the electric heater close to the location where you’ll be using the water. If you can’t install the gas heater close to the kitchen and bathroom, it might be better using an electric heater, otherwise I’d go with gas.
The problem is not so much the couple of showers a day. It’s more the quick warm wash for things like the frying pan you want to use now, the cup, your hands etc. If the heater is far away from the kitchen and bathroom each time you want a little hot water it will fill up the whole water-pipe first.
My kitchen is about ten meters of pipe away from the gas heater and I am considering getting in addition to gas a continuous-flow water heater either 110V or 220V.[/quote]
That thing draws a massive 120 amps even at 240 volts and it still only delivers 15 liters per minute. Regular house wiring just can’t cope with that kind of load.[/quote]
Actually, you are right.
I just recalled that the heater I used was 360V not 220.
I’ve done a bit more research and it seems that the electric on demand boilers don’t go higher than 16 litres per minute. That makes me think that the bloke is talking about some kind of boiler with a tank which heats and stores a bathload and then delivers it very quickly.
The house is a new house, never been lived in. It has a gas pipe so running a gas boiler would not require bottles.
It also has the rack on the roof for a solar powered water heating system, but it’s in Taoyuan which I’m told is the cloudiest and rainiest county in Taiwan. It seems to me that the sun only comes out properly between May and October, so the only time it’s going to heat the water enough is exactly when you don’t want to take a hot shower or bath.
My wife says that bloke told her that the heater he is talking about can fill the bath in ten minutes. I’ll have to get my wife to translate next time because I’ve got no idea what it is. However, it seems clear that a gas boiler is considerably cheaper to operate than an electric one.
Thanks to everyone posting, your knowledge is very useful and appreciated.
I live in Taoyuan also and the irony isn’t lost on me. During summer, you have on tap all the solar-heated water you could wish for - but ambient temperature showers are more refreshing. And during winter, when you want a hot shower, the sun won’t show itself for weeks on end.
The residents on the top floor of my apartment block all have solar heating installed, but I wonder how much use they get out of it. Seems a very expensive investment just to provide dishwashing water.
They’re not actually that expensive - the wholesale price is about NT$600/tube (~8 per square meter) plus maybe NT$20000 for the tank, mounts and header. The problem is that installers add a huge markup, people don’t install enough tubes, and nobody has ever heard of absorption refrigeration (solar-fired aircon) in Taiwan. In summer you should get about 6MJ/m2/day, and one-third of that in winter. If you reckon on 100kJ per litre of hot water (23’C temperature rise) you need >4m2 of collector area to make it worthwhile. Most of the installations I’ve seen are only half that. As for flat plate collectors (which some installers are still pushing) … like you say, they’re only good for summertime or dishwashing.
Would definitely go with gas. Had an electric type with insulated storage tank whilst living in China, it was about a third the volume of the bathtube so you had to set it to the highest temperature possible (~75C), get about half the tub filled with hotish water, then wait for the tank to reheat before topping off the bath. Similarly if you wanted a shower etc, would need to either set the timer or wait for the water to heat, ended up just leaving the thing turned on all the time as electricity was relatively cheap.
If you have gas then just get a regular gas water heater, I used to run one in Taiwan on a 20KG gas bottle without any issues, if you have piped gas then it’s a no brainer.
It would seem that no one has much good to say about electric boilers but my wife wants one because a bloke she doesn’t know told her they’re better. How can I change her mind? Is there a definitive cost comparison for the two types in Chinese that anyone knows about? I can’t type or read Chinese but I feel sure there must be something on the www.
