Water pump size.

[Orinoco]

Hi Guys

Need some advice, how big does the water pump need to be for a

Single story house 120 square meters, two hot water showers standard Thai type, washing machine, two toilets 3 sinks. Total

Only two maximum in use at the same time for a short period of time, Pressure for shower does not need to be like a fire house.

Feeding off a floor level tank from the mains. Using standard blue 1 inch pipe.

Would 150 watt pump be ok or do I need bigger, was thinking about a Hitachi

Automatic style pump.

Thanks Orinoco.

[bankruatsteve]

150-250 watt is what most of us have. 250 mostly for two story. Hitachi and Mitsu are the popular brands. 

[Orinoco]

1 minute ago, bankruatsteve said:

150-250 watt is what most of us have. 250 mostly for two story. Hitachi and Mitsu are the popular brands. 

Thank you for your reply

Maybe get in the middle at 200 ?

[VocalNeal]

Here ya go.

 

http://mitsubishielectricmalaysia.com/products/water-pump/q3/water-pump-specs.jpg

 

[sandyf]

5 minutes ago, Orinoco said:

Thank you for your reply

Maybe get in the middle at 200 ?

My house is effectively as you describe and I have had the same Hitachi 150 running day in day out since 2010. Only problem, I had to change the pressure switch a couple of years ago when it started to leak.

The pressure is quite adequate but if it were to pack up I would replace it with the next size up.

I also bought a Mitsu 100 at the same time and due to corrosion had to have a stainless tank fitted to that after about 18 months.

I also have a Hitachi 300 deep well pump which is now over 8 years old and never been a problem.

[Orinoco]

4 minutes ago, sandyf said:

My house is effectively as you describe and I have had the same Hitachi 150 running day in day out since 2010. Only problem, I had to change the pressure switch a couple of years ago when it started to leak.

The pressure is quite adequate but if it were to pack up I would replace it with the next size up.

I also bought a Mitsu 100 at the same time and due to corrosion had to have a stainless tank fitted to that after about 18 months.

I also have a Hitachi 300 deep well pump which is now over 8 years old and never been a problem.

Hi Thank you for your reply

Ok, so 150 should be ok, but 200 better, will keep eye open for a 

good deal in the next 3 months, as wont need it till then, still only got  

10% of house built yet !!!!!!!!!!!!!!!!!!

Thanks again.

 

 

[sandyf]

10 minutes ago, Orinoco said:

Hi Thank you for your reply

Ok, so 150 should be ok, but 200 better, will keep eye open for a 

good deal in the next 3 months, as wont need it till then, still only got  

10% of house built yet !!!!!!!!!!!!!!!!!!

Thanks again.

 

 

A point to bear in mind is your shower heaters. I have 4.5Kw and they just about manage during the winter months with the 150 pump. If I were to move up to 200 I may have to fit a flow control to the heater.

Would be less problematic to have higher rated heaters fitted in the first place, but you may well have that in mind anyway.

[Orinoco]

6 minutes ago, sandyf said:

A point to bear in mind is your shower heaters. I have 4.5Kw and they just about manage during the winter months with the 150 pump. If I were to move up to 200 I may have to fit a flow control to the heater.

Would be less problematic to have higher rated heaters fitted in the first place, but you may well have that in mind anyway.

Was going to keep the showers down to the lowest wattage possible.

as only need tepid water on  those chilly mornings in Esan.

[Orinoco]

39 minutes ago, VocalNeal said:

Here ya go.

 

http://mitsubishielectricmalaysia.com/products/water-pump/q3/water-pump-specs.jpg

 

Thank you for your reply.

will have a look.

[Orinoco]

This model looks like it fits the bill ?

[bankruatsteve]

Check out the "constant pressure" types. Mine is GX series. 150W should be enough for you based on your OP. 

[sandyf]

4 hours ago, Orinoco said:

Was going to keep the showers down to the lowest wattage possible.

as only need tepid water on  those chilly mornings in Esan.

That  was the view I took, the electrician had said there was a significant price difference to go to 6Kw and above and what we have does the job

We don't have mains water, being surface water that is not too bad in the winter but take it from me the water from the well can take your breath away if not boosted a bit by the shower heater. Good luck.

[bankruatsteve]

Just recall you saying that your house is only 10%... Suggest you tell the builder to maintain the 1" pipe until the need to reduce to 1/2".  Otherwise they will go to 1/2" immediately.  That would be for outside faucets as well.  Especially when going under concrete.  That is the one thing I wish I could re-do in my house.

[The Theory]

If you don't want the pressure waves (up/down) then go for "constant pressure". And not more than 

off 1.6 kgf/cm2

on  2.2 kgf/cm2

otherwise it will keep on/off 

same as a pump with pressure tank. 
 

and still it depends on the users/pipes size.

[Orinoco]

45 minutes ago, The Theory said:

If you don't want the pressure waves (up/down) then go for "constant pressure". And not more than 

off 1.6 kgf/cm2

on  2.2 kgf/cm2

otherwise it will keep on/off 

same as a pump with pressure tank. 
 

and still it depends on the users/pipes size.

Thank you for your reply

 

[MrJ2U]

These pumps are like your bed.  Get a good one. 

 

I got a Mitsubishi Super Pump because I like a nice shower.  We've got a two story house with 3 full bathrooms.  We're really happy.

I got good deal on Lazada for around 12,000 baht.

 

 

[Orinoco]

9 hours ago, MrJ2U said:

These pumps are like your bed.  Get a good one. 

 

I got a Mitsubishi Super Pump because I like a nice shower.  We've got a two story house with 3 full bathrooms.  We're really happy.

I got good deal on Lazada for around 12,000 baht.

 

 

Not so sure that would be a good idea.

With pressure like that and the modern day adjustable, multi setting,  shower heads

that could render me not so useful, in the future.

So will pass on the high delivery pump. LOL.

 

[rumak]

21 hours ago, sandyf said:

My house is effectively as you describe and I have had the same Hitachi 150 running day in day out since 2010. Only problem, I had to change the pressure switch a couple of years ago when it started to leak.

we have had 4 Hitache 150  pumps...... 4 seperate houses....... also still running ( 15 years! ) .    On two we also

replaced the pressure switch  (about 200 baht,  and can easily done by oneself) .    Single story homes

 

i like the oval ones....... had one rectangular which needed a part replaced after 3 years

[sandyf]

1 hour ago, rumak said:

we have had 4 Hitache 150  pumps...... 4 seperate houses....... also still running ( 15 years! ) .    On two we also

replaced the pressure switch  (about 200 baht,  and can easily done by oneself) .    Single story homes

 

i like the oval ones....... had one rectangular which needed a part replaced after 3 years

Yes, I did it myself. I also had to replace the pressure switch on the Hitachi deep well pump not that long ago. That was a bit more difficult as the wires on the replacement were significantly shorter.

[ronster]

I have basically a similar house . I use 200w Mitsubishi but that was just to be safe . 150 would probably do it also , but for difference of 1000 bht or so I didn’t see point in buying less powerful one .

[bankruatsteve]

1 minute ago, ronster said:

but for difference of 1000 bht or so I didn’t see point in buying less powerful one .

One point would be lower energy consumption.

[carlyai]

17 hours ago, bankruatsteve said:

Just recall you saying that your house is only 10%... Suggest you tell the builder to maintain the 1" pipe until the need to reduce to 1/2".  Otherwise they will go to 1/2" immediately.  That would be for outside faucets as well.  Especially when going under concrete.  That is the one thing I wish I could re-do in my house.

Yes that's great advice. Keep the water pipe 1" as suggested and 13.5 (thicker walled pipe) as well. Keep a good eye on the pipe worker as you tend to be too busy to watch them. Especially if you are installing the green hot water pipe that just pushes into connections as well. 

[Prairieboy]

23 hours ago, Orinoco said:

Hi Thank you for your reply

Ok, so 150 should be ok, but 200 better, will keep eye open for a 

good deal in the next 3 months, as wont need it till then, still only got  

10% of house built yet !!!!!!!!!!!!!!!!!!

Thanks again.

 

 

A word of advise - use the best quality plumbing and before burying it, or embedding it, perform a 2 hour hydro static pressure test to detect any leaks.  Some of the 'plumbers' do very shoddy work and use the cheapest material available.  Once a system is embedded as they do here in Thailand repairing a leak becomes a major undertaking!  Been there done that! 

 

https://www.mcwaneductile.com/blog/how-to-successfully-prepare-and-complete-a-hydrostatic-test/

 

I use Hitachi pumps (we have 2 homes) and have a 300W and 350W  - especially helpful if you plan on watering your lawn, etc.

 

[bbko]

My house is similar to the OP and our 15+ year old 150 pump started acting up a few weeks ago and the pressure seems to be going down.  So I bought a new Mitsubishi EP-205R off of Lazada for about 600B less than what Home Pro was asking for the exact same item. 

I haven't installed it yet as the old 150 is still performing ok, but as I keep telling the misses "I'll get around to it soon", 555. 

[MrJ2U]

On 7/16/2021 at 6:33 AM, Orinoco said:

Not so sure that would be a good idea.

With pressure like that and the modern day adjustable, multi setting,  shower heads

that could render me not so useful, in the future.

So will pass on the high delivery pump. LOL.

 

I haven't had any problems.

Personally I enjoy the high pressure showers.

But I can understand being on the safe side.  Good plumbers are hard to find.

[MrJ2U]

4 hours ago, bbko said:

My house is similar to the OP and our 15+ year old 150 pump started acting up a few weeks ago and the pressure seems to be going down.  So I bought a new Mitsubishi EP-205R off of Lazada for about 600B less than what Home Pro was asking for the exact same item. 

I haven't installed it yet as the old 150 is still performing ok, but as I keep telling the misses "I'll get around to it soon", 555. 

It's smart to check Home Pro, Global, even small mom and pop shops.

Then check Lazada and Shopee, due diligence will save you a lot.  Online has usually been my best prices.

[Yellowtail]

The higher wattage pumps generally relates to to volume the pump delivers, more than that pressure.  

[sometimewoodworker]

12 hours ago, Yellowtail said:

The higher wattage pumps generally relates to to volume the pump delivers, more than that pressure.  

Mitsubishi seems to disagree with that, as yes the volume is higher but so is the pressure after you go above 155w 

[Yellowtail]

3 hours ago, sometimewoodworker said:

Mitsubishi seems to disagree with that, as yes the volume is higher but so is the pressure after you go above 155w 

No, you disagree with with, Mitsubishi and I are in agreement. 

 

[driver52]

On 7/15/2021 at 9:39 AM, sandyf said:

We don't have mains water, being surface water that is not too bad in the winter but take it from me the water from the well can take your breath away if not boosted a bit by the shower heater

how deep is your well out of interest? Any idea of the water temps in there?

I only ask cos I thought in the tropics the land temps were not much different to the air temps and that's why geothermal cooling systems don't make much sense