Hot Water Pumps For Showers?

[technocracy]

Ok so currently the house is under construction and the plan is to install a large 100 litre water heater upstairs - there is a 2 ensuites and a bathroom downstairs and upstairs a main bathroom.

Obviously gravity will give an ok feed - however ideally I'd like to stick a pump on the hot water to give a proper power shower effect.

Can you buy any hot water pumps in Thailand? I looked in HomePro and the hapless assistant kept pointing me towards the cold water Mitsubishi pump (I am sure they are on commission to sell those things as they are the only one they point at for anything!) even though I pull out the spec sheet which clearly said 35C max temp. Same for the Grundfos which I will be using for my cold water.

Anyone have any experience with pumps for hot water?

[lopburi3]

If you are using the Grundfos for the cold water input to your water heater the output, of the water heater, will be at the same pressure so do not understand why you are talking about gravity. The one HP model provides 65psi which is plenty strong enough for a good shower.

Or are you talking about a passive water tank heated by the sun or something like that?

[Crossy]

I would re-consider the use of a European style hot water storage system in favour of direct water heaters at each shower. Less pipe and it only heats the water you use (or am I barking up the wrong tree here?).

We don't use the vast volumes of hot water that we would in a cooler climate.

[technocracy]

I would re-consider the use of a European style hot water storage system in favour of direct water heaters at each shower. Less pipe and it only heats the water you use (or am I barking up the wrong tree here?).

We don't use the vast volumes of hot water that we would in a cooler climate.

Basically the size will be considered at the point of purchase - the reason for the using a central storage is really for convience of hot water available in all bathrooms (taps included) and beable to have a bath (the wife not me - not something I've ever enjoyed!).

The Stiebel Eltron range is one of which we are considering.

http://www.stiebeleltronasia.com/psh.htm

But also I have seen the solar powered ones also - albeit big and ugly - which are also under consideration.

So the question remains . . . a pump for hot water - is there such a thing in Thailand?

[elkangorito]

I looked at the website & it doesn't indicate if the units are 'mains pressure' or not. But as another poster indicated, if the cold water input to the unit will be under pressure (via a cold water pump), then you will not need any other pump.

Another serious thing to consider is the 'pressure relief valve' (only if it is a 'mains pressure' unit), which must be manually operated every 6 months.

The common type of mains pressure HWS (Hot Water System) are;

1. Glass lined - medium to high pressure (100 psi). High temperature (85 degrees C). These generally have a long life if the temperature & pressure is reduced.

2. Steel - High pressure & high temperature but is prone to rusting relative to the water supply quality. Reasonably long life.

3. Copper - this is the Rolls Royce of storage HWS's. Has a very long life, can handle high temperature & pressure.

All the above units must be fitted with an appropriate pressure relief valve. In Australia, these units are available in sizes ranging from about 50 to 400 Litres & absorb up to 4.8kW of power.

Don't forget, the average person will use from 40 to 80 Litres of hot water for a 10 minute shower. The total water used for a 10 minute shower is anything up to about 120 Litres.

[Shola]

I would defo recommend a gas water heater as electrical heaters really push up your power bill, our house is under construction too, weve hidden the gas bottle in one of the kitchen cabinets. My hubby's Thai and he says gas heating of water will be way cheaper. We got the heating unit in Homepro for about 6000B.

[GuestHouse]

If you are going to install a bulk hot water tank I would suggest you consider installing a solar water heater, heating gallons of water by electricity, or even gas, is going to be hugely expensive in the long term - Not to mention environmentally unsound.

You have access to limitless free heat from the sun, why not use it?

[ProThaiExpat]

Most of us who have come from western cultures where the waste of energy is so gross, welcome the efficiency of using room airconditioners and individual heaters for each bathroom prevalent in Thailand.

When you think how much energy is being wasted by keeping a tank of water at a fixed temperature during the night when everyone is sleeping for many hours, the term reckless comes to mind. Central air conditioning has its merits, but I remember well shutting off rooms not in use when I had central air conditioning in the west.

I built my own house and used the Thai individual approach and couldn't be happier, unless of course I converted to gas water heaters and gas clothes dryer.

[lopburi3]

I would defo recommend a gas water heater as electrical heaters really push up your power bill, our house is under construction too, weve hidden the gas bottle in one of the kitchen cabinets. My hubby's Thai and he says gas heating of water will be way cheaper. We got the heating unit in Homepro for about 6000B.

Not the type used here in Thailand. They only draw power during use. You only use about 5 minutes for a normal shower (one or two to lather up) and then a couple minutes to rinse. You turn water off between and no power is used. In Bangkok the average draw is probably less than 2kw when in use (max is normally 3.5). That would be 12 showers for 8 baht of electric power. So you are likely only talking about 1,000 baht per year for two showers a day for two people.

[jing jing]

Get a multipoint on-demand electric water heater and mount it under the sink -- you can then have hot water for your sink and tub. Steibel Eltron makes a couple of different models.

[elkangorito]

If you are going to install a bulk hot water tank I would suggest you consider installing a solar water heater, heating gallons of water by electricity, or even gas, is going to be hugely expensive in the long term - Not to mention environmentally unsound.

You have access to limitless free heat from the sun, why not use it?

Absolutely the best way to go. And don't bother fiddling around with small storage systems...get at least 250 Litre Solar system. Instantaneous Hot Water Services are very cheap to run if your household has no more than 2 people, otherwise they are the most expensive to run.

[stevejones123]

The thing you want is what in the UK is called an Ascot heater. That is a gas heater that heats the water you use. You run it off bottled gas, and keep it in the kitchen and it will provide hot water for all the house.

Finding one might be a nuisance. I have an electric one for my house in Sri Lanka, but it's not that good.

[technocracy]

If you are going to install a bulk hot water tank I would suggest you consider installing a solar water heater, heating gallons of water by electricity, or even gas, is going to be hugely expensive in the long term - Not to mention environmentally unsound.

You have access to limitless free heat from the sun, why not use it?

Absolutely the best way to go. And don't bother fiddling around with small storage systems...get at least 250 Litre Solar system. Instantaneous Hot Water Services are very cheap to run if your household has no more than 2 people, otherwise they are the most expensive to run.

Elkangorito,

"Instantaneous Hot Water Services are very cheap to run if your household has no more than 2 people, otherwise they are the most expensive to run."

My thoughts exactly! Also as stated previous instanteous water heater don't provided a bath!

But I now understand the thoughts on the pressurised system - ain't something I've ever dealt with before!

As for the storage system to be used I am going to be looking at them in the coming weeks.

[firstknight]

is it allowed to install a pump in the house?? I heard that it not allowed....

[mackayae]

You can use two Grundfos pumps. One for your cold water system and one for your hot water system. Put the hot water pump on the input (cold) side of the 100 liter water heater. Position the pumps side by side and interconnect them so you have four modes of operation:

1. Pump # 1 supplies both hot and cold water.

2. Pump # 2 supplies both hot and cold water.

3. Pump #1 supplies hot water, Pump #2 supplies cold water.

4. Bypass mode, both pumps off, water supplied by city supply and/or storage tank.

The nice benefit of this method is your hot water pressure is not affected by changes in the cold water pressure.

[technocracy]

You can use two Grundfos pumps. One for your cold water system and one for your hot water system. Put the hot water pump on the input (cold) side of the 100 liter water heater. Position the pumps side by side and interconnect them so you have four modes of operation:

1. Pump # 1 supplies both hot and cold water.

2. Pump # 2 supplies both hot and cold water.

3. Pump #1 supplies hot water, Pump #2 supplies cold water.

4. Bypass mode, both pumps off, water supplied by city supply and/or storage tank.

The nice benefit of this method is your hot water pressure is not affected by changes in the cold water pressure.

Cheers for that Mackayae - interesting idea.

Firstknight - never heard anything about them not being allowed to be installed inside, some are specifically design to be used indoors. In my case as I'll be using it purely from a water storage tank positioned behind the kitchen wall the pipe will enter the kitchen and go straight into the pipe. Well that how I believe it will be connected - I'll see when the plumber comes to put it altogether!

[Upcountry]

We just upgraded our water pump to a 250w unit (from an old, dying 150w). It feeds plenty of pressure to our individual water heaters, and all outputs, (hot or cold). No problem filling a bathtub with hot water, etc. In fact, it almost too much pressure for some connections. If I could do it over, I might have gone for 200w instead. But we may be glad later, when we expand the house.

[rken]

I recently because of low water presure in the morning installed a water holding tank and pump to supply a point of use hot water heater. But agree with an ealier posting that if you want to use a hot water heater, supply side presure will work (inlet side of water heater) well without the need for a pump that will pump hot water in design. 40 years construction experience.

[rken]

Gas is definately much cheaper then electric for point of use water heating. but a tank indoors is asking for problems. 40 years construction and 10 years volunter fire department in hawaii. mostly gas system. the potential for fire with and indoor is expontential not to mention the lose of life. Take it from experience if you have an indoor tank move it outdoors.

[elkangorito]

You can use two Grundfos pumps. One for your cold water system and one for your hot water system. Put the hot water pump on the input (cold) side of the 100 liter water heater. Position the pumps side by side and interconnect them so you have four modes of operation:

1. Pump # 1 supplies both hot and cold water.

2. Pump # 2 supplies both hot and cold water.

3. Pump #1 supplies hot water, Pump #2 supplies cold water.

4. Bypass mode, both pumps off, water supplied by city supply and/or storage tank.

The nice benefit of this method is your hot water pressure is not affected by changes in the cold water pressure.

Can you please tell me how this works?