Gas water heater

[sumyunggai]

So I looked at some gas water heaters (electricity is bad here, so no way). however they are low-end 5l/minute models costing around 2 million.

This would be ok at 1 per room, but I think the flow rate is unsatisfactory for a good shower, and these models are basically suitable only for a kitchen. So it seems better to get something like 30 litres/minute. I looked online and didn't see much in Indonesia? Any suggestions?

 

[Bad_azz]

So I looked at some gas water heaters (electricity is bad here, so no way). however they are low-end 5l/minute models costing around 2 million.

This would be ok at 1 per room, but I think the flow rate is unsatisfactory for a good shower, and these models are basically suitable only for a kitchen. So it seems better to get something like 30 litres/minute. I looked online and didn't see much in Indonesia? Any suggestions?

Don't look online, ask around the locals & they will tell you the best place to shop for them in your area.

 

[sumyunggai]

Don't look online, ask around the locals & they will tell you the best place to shop for them in your area.

The locals don't have a clue. They use 300W on-demand electric water heaters which don't work properly and Western visitors complain, or they use bigger water heaters which they back up with massively expensive gensets - also badnews.

I'm looking for a make and model that is capable of some serious flow, not just a trickle.

 

[Smallworld]

So I looked at some gas water heaters (electricity is bad here, so no way). however they are low-end 5l/minute models costing around 2 million.

This would be ok at 1 per room, but I think the flow rate is unsatisfactory for a good shower, and these models are basically suitable only for a kitchen. So it seems better to get something like 30 litres/minute. I looked online and didn't see much in Indonesia? Any suggestions?

You may not seen them in Indonesia because ... it would be more dangerous to use them. Not only you have to worry about gas leaks but also fumes going out from burning gas CO2 and the deadly CO (working chimney/ventilation shaft is a must). How many houses do have those chimneys or ventilation shafts, who and how is checking if they are working?

Please remember you have to provide min water pressure if you use boiler. If your water pressure sucks (remember you want 30 ltr/min) and it does in many urban areas in Indonesia then it would be not appropriate to have boiler heater (damaging boiler). They also consume/burn a lot of gas. The more powerful boiler the more gas they burn. It is not about end bill each month but a bit of "inconvenience" of getting new gas tanks every few days. At least this is how I see it.

My options would go to:

1. Electrically heated water in a tank isolated with mineral wool.
2. Using ordinary kompor for cooking to heat a bucket of hot water and then while taking shower mixing cold and hot water with gayung.
3. Solar heated water on the roof.

 

[Jaime C]

Solar hot water heater won't work? You can make some pretty cheap setups.

 

[Wisnu]

Large (relatively) capacity gas water heater is not popular for home in Indonesia. Indeed, the most common is 5 l/m but Rinnai produce instant gas water heater with capacity 16-20 l/min.
You can also find in Indonesia Ariston gas water heater with storage capacity more than 300 l. The NHRE 90 might suit your requirement.
Making gas water heater is not difficult, but the demand for home user large capacity in not muc in Indonesia; however, I believe you can find the 30 l/cap. in glodok or pasar kenari.

 

[jstar]

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Jaime is right; look for a passive solar water heater for on the roof first. If you put it somewhere else you will need a pump of course. (No water pressure.) And that makes it expensive since only the Grundfos can deal with that heat.

The solar heater is best the model with the tubes, it does not get clogged as those flat panes.

If that is really impossible, there are gas heaters available. In places like Glodok they are very easy to find but even bigger DIY shops (as Mitra10) have them. But the quality kind of sucks.

An alternative is the small electric boiler; if you have a 15 (1 person) or 30 (2 person) liter model it should be okay since the water temperature here is always rather high. Those consume 600-1200 Watt and can be found in any DIY shop.

 

[Bad_azz]

I used to have a gas heater- and it was great, I forget what make/model etc it was though- and I refused to have the gas bottles in the house so a pipe was rigged up from the outdoor bottle on the ground floor to the upstairs bathroom.
The water flow was always pretty good and the water was always piping hot. The hardest part was twiddling the taps to get the perfect temperature mix- as is the norm with having a shower hehe.
Anyway- I am not much help- maybe try buying one - seeing how it goes then buying more if it is ok.

Where do you live?
if Bandung, I would be able to suggest some places to look.

 

[sumyunggai]

we have our own ground water. I want to provide Western-style power shower so I am not considering a kompor (!).

Tank is ok, but I don't want people (paying guests) complaining when it runs out, so I think you still need backup.

 

[sumyunggai]

.
An alternative is the small electric boiler; if you have a 15 (1 person) or 30 (2 person) liter model it should be okay since the water temperature here is always rather high. Those consume 600-1200 Watt and can be found in any DIY shop.

How does that work?

With 30l, the tank is emptying by 7.5 litre/minute, but at 10C heating, you need:

7.5l * 4200 (specific heat capacity) * 10C /60s = 5.25kW

So it seems 30l gives only a 4 minute shower and then you must wait 21 minutes for it to heat up again?

 

[jstar]

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I think you overestimate the emptying rate over here. A comfortable shower (for Western standards) is normally between 40 and 70 liter at 35-37° Celsius. But here in this climate the people prefer lower temperatures, esp. later during the day. For 50 liter warm water you need 20 liter heated water in a factor 2.5, but that is when the cold water supplied is less than 10 degrees! Don't forget that the water is already up to 20-25° when in a water tank on the roof, so over here the factor can easily be up to 5.

Also, because of the higher inflow temperature and smaller usage, the warm up time is not that bad.

Still, I would use the solar as main supply and the other solutions only as exceptional backup. Electricity is expensive compared to the sun. And even in the rainy season the system works well, without additional electrical heating. (Which is an option for the solar tank btw.) In a Jakarta house we have all bathrooms on solar heater but one; that is a backup on 30L electric. And it worked perfectly for three people when there was a family home invasion because of the flooding.

Now with the solar system you can easily get an integrated capacity of 250 liter and you will find that is enough for eight people.

And believe me, you will need a water tank, far too risky without. So one high capacity cold water tank with separate hot water storage. No water is worse than cold water.

Btw, the wall model gas water heater is something we had in Europe in the seventies. We called it geiser; it was installed in the kitchen and also served for the bathroom. But even in many Hong Kong appartments, you still see this solution. And the bathrooms in the house of my M-I-L have it too. And B_a is correct; it is almost impossible to regulate the tap without the water getting too hot or ice cold returning to the wake flame. (Or completely off in case of electronic ignition.) Bah.

 

[sumyunggai]

.
I think you overestimate the emptying rate over here. A comfortable shower (for Western standards) is normally between 40 and 70 liter at 35-37° Celsius. But here in this climate the people prefer lower temperatures, esp. later during the day. For 50 liter warm water you need 20 liter heated water in a factor 2.5, but that is when the cold water supplied is less than 10 degrees! Don't forget that the water is already up to 20-25° when in a water tank on the roof, so over here the factor can easily be up to 5.

Ok, so you are taking 1l of 60C water and mixing it with 1l of 20C to make 40C water, for example.

A factor of 5 seems very optimistic. We have water in a concrete tank and it seems to vary between about 20C and 23 or 24C, let's say 25C at max. If you went for 35C, which is not great, that requires your water tank to be heated to 85C even starting at 25C for a factor of 5, which is unreasonable.

Btw, the wall model gas water heater is something we had in Europe in the seventies. We called it geiser; it was installed in the kitchen and also served for the bathroom. But even in many Hong Kong appartments, you still see this solution. And the bathrooms in the house of my M-I-L have it too. And B_a is correct; it is almost impossible to regulate the tap without the water getting too hot or ice cold returning to the wake flame. (Or completely off in case of electronic ignition.) Bah.

Isn't that just a question of a separate mixer? The gas heater is rated for 25C heating above input, so if your water is at 22C and you want 37C water, then you need to mix your water in a ratio of 3:2. Given the output of 5l/minute from the heater, that means a total water flow of 8l/minute.

 

[jstar]

It doesn't really matter if your mixer (kran) is on the unit or separately on the wall; the problem is that the gas burner doesn't function well with tiny hot water demands; it toggles between on and off.

The electric boilers can normally support up to 80°, depending on the brand and some go higher. (Calcium!) The Rolls Royce is the Dutch brand Daalderop btw, for sale in a Mitra10 for instance. But I'm also quite happy with the much cheaper Modena.

The solar heater often has a much higher temperature; the expansion tank and extra overflow provide security.

 

[sumyunggai]

Hmm, isn't tiny hot water demand a function of having otherwise shitty plumbing?

For example, as noted the single 2/3 juta gas heaters are rated for 5 litres/minute @ 25C heating above input.

Grohe says:

'Our 130mm and 160mm Rainshower hand shower uses 8l/minute, 20% less than our competitor'

'Our Rainshower Jumbo 400mm head shower uses 18l/minute, up to 50% less than our competitor'

So if you are producing 5l/minute of water in the 45C-50C range, then the burner should be on full blast?

 

[jstar]

Thermostatic and the so called 'savings' faucets and shower heads cope with this gas burner issue more often. And it also occurs because of calcium in the water pipes. Has all to do with insuffient hot water flow of course so the gas burner will shut down.

I only have a rainshower in my own bathroom (I'm not crazy and rather stingy). For that, even the placement of the watertanks on the high roof could not provide enough pressure. So I had to install a pump for cold and one for hot water. This was not really necessary for the normal showerheads.

 

[Smallworld]

we have our own ground water. I want to provide Western-style power shower so I am not considering a kompor (!).

Tank is ok, but I don't want people (paying guests) complaining when it runs out, so I think you still need backup.

You see you haven't mentioned those informations in your first post. By "your own ground water" I understand you mean you have a well.

As for the tank I personally think it is a necessity in Indonesia. Not only the tank water will get heated on top of your house saving you some money but it will also provide you water at all the time as a additional storage (as long as it was always refilled). Remember there are dry seasons here in Indonesia. Some wells dry out some don't.
If you don't want guests complaining about "no water" - remember always to refill the tank as simple as that... if you cannot refill it (eg. working, busy, forgetful) maybe someone else can do it (your maid, wife,gf -anyone else living there who can remember about it).
As a last resort you can use timer which will switch on the pump at specific times each day.

 

[Bad_azz]

I don't think it would hurt paying guests to be aware of the water issues in Indonesia (not all of it & I don't know your location- but some areas such as Lombok and Bali have a real problem that is only going to get worse).
So some information in the booking forms to say that you encourage guests to be aware of these environmental issues and that you respectfully ask them to understand etc. wouldn't be unreasonable.

 

[Davita]

You see you haven't mentioned those informations in your first post. By "your own ground water" I understand you mean you have a well.

As for the tank I personally think it is a necessity in Indonesia. Not only the tank water will get heated on top of your house saving you some money but it will also provide you water at all the time as a additional storage (as long as it was always refilled). Remember there are dry seasons here in Indonesia. Some wells dry out some don't.
If you don't want guests complaining about "no water" - remember always to refill the tank as simple as that... if you cannot refill it (eg. working, busy, forgetful) maybe someone else can do it (your maid, wife,gf -anyone else living there who can remember about it).
As a last resort you can use timer which will switch on the pump at specific times each day.

My tank, on the roof, has a float-switch which turns ON the well-pump and automatically refills when water being used.
The tank feeds another pressure-switched small pump which provides pressure any time a faucet or shower is turned ON. If there is power failure gravity will feed (lower pressure) until the tank is empty.
I thought they were all like that.

 

[fastpitch17]

My tank, on the roof, has a float-switch which turns ON the well-pump and automatically refills when water being used.
The tank feeds another pressure-switched small pump which provides pressure any time a faucet or shower is turned ON. If there is power failure gravity will feed (lower pressure) until the tank is empty.
I thought they were all like that.

No, that is something you add and as far as I'm concerned, a good addition. At least the float system to refill the tank. I have mine set to when tank is 1/3 empty to refill. I decided I didn't need the pressure pump since my tank is so high and I get great pressure without it. When there is a power outage I know I have plenty of water at my disposal until power comes back on. I see all this new construction outside my perimeter wall of my complex where they are just putting in submerged pumps and every time the power goes out, they have no water. Then, they add gensets. I think the tank system investment would have been cheaper then a genset and then the gas to run it when needed.

 

[jstar]

I have -besides the sensor which is mounted on the water tank- also added a foam ball to close the inflow if the pump keeps on running.

And the big pump was overheating when there were Aetra problems and no water supply. So now I put a timer on that pump that activates four times 15 minutes per day.