Solar Water Heater Hurdle

[Jenkins9039]

Hi, had a comment before (can't find).

 

Our home only has one pipe coming to the shower(s) with hot water from heaters above the ceiling (each shower x 3).

 

I want to install solar water heating - but hitting a hurdle, the company sais that a new green pipe needs to be run. and you manage the mix of hot/cold at point - this is not something we want to do, as each wall would have to be retiled (100k per wall before we even start - and struggle to find the same tiles as discontinued - been there).

 

So my idea, is there must be a way that the solar heater heats the water, its then gravity fed/pumped to a mixing tank of sorts before flowing to the house shower (heads) - we are only interested in the showers - we have 5kw system and 3kw system for the pool, each shower heater when used uses 3.5kw so we have a power issue at times (too much being consumed). 

So as you can see - cutting out the heating of water will take some pressure of the house grid, but doing so will create extreme costs making it not worth while/viable.

 

Has anyone come across a tank of sorts that can mix the hot water coming from the solar hot tank with cold water that we can then send onto the house?

 

Thanks 

 

- did see this but looking for a off the shelf solution i can just give to somchai

 

[Bandersnatch]

We have a solar water heater which we installed when we built the house a few years ago.

 

I think you are going to want to have manual control at the shower, because the temperature of solar thermal water in Thailand varies from near boiling to pleasantly warm. I have a “cold” feed blue pipe from a tank of filtered rainwater and a hot feed from the solar thermal. I vary the percentage of hot from 0-100% depending on the season. My Thai wife’s preferred percentages are obviously different to mine.

 

I don’t think you are going to have to re-tile as you can drill through from the tile side of the bathroom to accommodate a 20mm green pipe without breaking tiles if you use plenty of water and a diamond tile bit (plenty of videos on online to help you)  

 

 

 

[Dante99]

17 hours ago, Jenkins9039 said:

each wall would have to be retiled (100k per wall before we even start -

Way too high.  Tilling does not cost that much.

[KhunLA]

Yes, hot water, green pipe.  The exact why, I don't know, though maybe blue PVC chemicals absorbed by water if hot, so not good.  You definitely want to control water temp at faucet with mixing, as stated, it can be scolding.   

 

We haven't needed to turn on our hot water heaters for some time now, as lukewarm, to very warm, and that's city piped water.  Not many houses on the line, so it sits in city pipes for some time on our soi.

 

I could easily bake bread if using city water now, as 105F to 115F.  Actually perfect time for bread ????  If using water heater (3500 watts) I could brew a cup of tea.

 

Had external roof mounted SS water tank at one house, and varied from freezing to scolding, depending what time of year.

[Muhendis]

3 hours ago, KhunLA said:

The exact why, I don't know,

Blue pipe for cold water is pvc which gets softer and softer the warmer the water.

Green pipe is PPR which has the tongue twister of Polypropylene Random Copolymer.

It's good for high temperature water and has excellent thermal resistance.

[Jenkins9039]

9 hours ago, Dante99 said:

Way too high.  Tilling does not cost that much.

Our tiles that are in place are not cheap. 

[Muhendis]

1 hour ago, Jenkins9039 said:

Our tiles that are in place are not cheap. 

can you get spares?

Or would you need to re-do the whole lot with different expensive tiles.

[Jenkins9039]

4 hours ago, Muhendis said:

can you get spares?

Or would you need to re-do the whole lot with different expensive tiles.

As mentioned - impossible to get now.

[Crossy]

How are you regulating the temperature now?

 

There's no reason not to have a solar pre-heat feeding your current heater but you would need some way of regulating the inlet temperature as the solar would be quite capable of boiling the water on a hot day!

 

You would need some form of thermostatic mixing valve on the feed to the existing heater. Not impossible.

 

Or, could you drill right through to fit a mixing tap in your existing shower, using a diamond hole saw and lots of coolant should avoid damaging the tiles. Of course, this would need access to the other side and assumes that the other side can be made good at sensible cost.

 

[Jenkins9039]

23 minutes ago, Crossy said:

How are you regulating the temperature now?

 

There's no reason not to have a solar pre-heat feeding your current heater but you would need some way of regulating the inlet temperature as the solar would be quite capable of boiling the water on a hot day!

 

You would need some form of thermostatic mixing valve on the feed to the existing heater. Not impossible.

 

Or, could you drill right through to fit a mixing tap in your existing shower, using a diamond hole saw and lots of coolant should avoid damaging the tiles. Of course, this would need access to the other side and assumes that the other side can be made good at sensible cost.

 

Have above ceiling water heater(s) on each shower like these that are in the roof (ceiling) 

[Jenkins9039]

Was considering installing one off these on the pipe off from the solar water heater, so it sends the right temp to the rooms (showers).

 

I'm not entirely sure how useful they are and whether they actually work, and then have a issue if the water temp is too low (cloudy days) will they function?

[bluejets]

On 5/21/2023 at 1:00 PM, Jenkins9039 said:

I'm not entirely sure how useful they are and whether they actually work, and then have a issue if the water temp is too low (cloudy days) will they function?

Work on about 10 million or more homes here in Aus...actually a mandatory install.