Brewing with the hot water tap

[dent]

Since I've moved to a house with solar hot water, I've been a bit peeved with not being able to use all that free hot water that, often in summertime, just boils over into the vent tube down the side of the house in a particularly wasteful fashion.

I considered filtering or ROing it but from what I've read it isn't a good idea for various reasons. Obviously it isn't recommended to use it directly with the extra metal content from the sacrificial anode. Plus, it smells funny.

But I got the idea last night, why not use the wort chiller in reverse - use the HWS water to heat the good RO water I have previously prepared so it can be used directly in the mash tun. Obviously there would be a fair bit of "chilled" HWS water left over, but I can just send that into a sprinkler for the grass or whatever.

Seemed like a pretty good idea to me.

 

[damoninja]

Great idea, it's good to see people considering their water / energy usage when brewing.

I'm not overly conservative, but the main reason I don't use a chiller is I can't justify using 400 litres of water to cool 25 litres of beer. Maybe if I had a tank I could hold it in until it cooled then I could use it on the garden, but down the drain is just offensive!

 

[law-of-ohms]

Interesting idea, I do use the hot water out of my natural gas hot water service, straight out of the pressure release valve, adjust to 65c with cold water.

I do have a 2000L water tank that I use for cooling my 'other' hobby.

 

[QldKev]

Not being negative, I do like the idea of trying to prevent wastage. One issue is the amount of hot water it may need. Our heat exchangers are not that efficient so the water will still be warm as it exits it ready for dumping, I guess you could run it very slowly. You could use some in the washing machine for a warm wash. The other issue I see depending on the age of the solar setup a lot of modern ones will not allow the water in the HWS get too cold to allow bacterial to live, so the backup heating will cut in. Once that happens it would be a lot more efficient to directly heat the water in the brewery.

 

[Bribie G]

I've always brewed with water out of the HWS.

I've also toyed with the idea of using those camper shower bags that you hang in the sun for a day but wonder about plastic or rubber taint.

 

[mje1980]

Interesting idea, I do use the hot water out of my natural gas hot water service, straight out of the pressure release valve, adjust to 65c with cold water.

I do have a 2000L water tank that I use for cooling my 'other' hobby.

Just be careful. If your relief valve hasn't been used in a long time, it may not re seal. I know this from experience. Had to change the bloody thing. Wasn't leaking before I used it, but I opened it once, and it wouldn't re seal.

 

[dent]

I figure since the HWS water is near boiling, it should be pretty much equivalent to the normal use of the chiller - on that the chilling water comes out hot enough for a mash, so I figure the reverse would be true.

Good point about the electrical heating backup - I know my system is completely manual, but others might not be so.

At least the leftover water can be used for something - when heating with electricity the leftover heat is good for nothing.

I can't justify using 400 litres of water to cool 25 litres of beer

I know I use a max of about 100L to chill a 50L batch - I run the hot waste water out into a big fermenter with the tap just cracked which slowly lets it onto the grass.. not awesome but better than the drain.

 

[damoninja]

I know I use a max of about 100L to chill a 50L batch - I run the hot waste water out into a big fermenter with the tap just cracked which slowly lets it onto the grass.. not awesome but better than the drain.

Well this is far more sensible. The guys I know who used to chill reckoned they'd use close to 400 litres, must have been a really shit chiller, maybe a little one and water running too fast.

If I can find an inexpensive big thing to hold the water I might consider constructing a chiller, it will probably water my chillis and tomatoes for a week.

 

[dent]

Full disclosure here - I don't even try to get down to pitching temp. Most of the year the tap water itself is well above the pitching temp I would like, so it would be folly to try to use that water alone. Usually I get it down to 30 ish and then put it in the fridge and pitch the next morning.

 

[law-of-ohms]

@mje1980

I'll have to post a pic of my 'modification'

 

[law-of-ohms]

Sorry it took awhile.

I went through two pressure relief valves before this.



When Hot water service is set to "4" water comes out @ 65c every time.

and there is ~300L of it.

nice and lazy

 

[Glot]

Bit hard to tell from the pic, but have you replaced the pressure relief valve with that assembly or is that on the water outlet?

 

[Glot]

Do you have a long or a short loop solar water system? That is, where is the storage tank located? The roof or elsewhere? If it is a long system with remote cylinder, then you could get a take off and return installed so you could go through your heat exchanger and then back into the solar panels. No water loss and making use of the energy from that big nuclear reactor out there.

 

[damoninja]

I'm hoping it's the latter.

 

[Glot]

Also, another point. For health reasons, it is not recommended to set the thermostat of your storage hot water heater set below 70 deg. The water needs to get above 60 deg but allowing for thermostat inaccuracies and occasionally heavy draw off meaning the holding time at lower temps( but above 60 deg) will not be long enough to kill legionella. This is why 70 deg is considered a safe setting. Depending on the heater, 72 deg is generally considered the most efficient setting for an electric storage hot water heater.
This is not advice intended for people making modifications to their hot water system. It is just general information and should be followed up with an appropriate person.

 

[law-of-ohms]

replaced the pressure relief valve with that assembly

 

[Glot]

Can you please let us know your address so we don't go within half a kilometre of your house. If it blows. it will take out a large part of your house, SERIOUSLY! NEVER EVER tamper with the PTR valve and manually operate it at least every 6 months. operating it. If you doubt my warning, search out the mythbusters demonstration. You can end up with a BLEVE!

 

[koots]

my god that is stupid

 

[dent]

 

[Glot]

It looked like a tempering valve to me that wasn't connected to cold water. Thanks for the link. This sort of thing has killed people.
In harder water areas, a pressure relief vale should also be installed in the cold water inlet. It is pressure only and not temperature. The reason is: In hot water, minerals crystallise out. These mineral deposits block and jamb the valve. The pressure relief valve on the cold water inlet is far less likely to suffer from mineral deposits. It has slightly lower operating pressure so it opens first. When ever a storage hot water heater heats, the water in it expands. If no taps are open then the pressure relief valve will release the excess pressure. I forget the actual figures but a 350 litre cylinder could release up to a few litres every time. This is NORMAL.
The gas hot water we are looking at in the pic MAY have a cold water pressure relief valve BUT it may not be rated for the full heating capacity and it would be pressure only, not temperature as well.