Methods for cooling incoming city water supply?

Elcam84 · 07-06-22, 05:53 PM

This is something that is an issue here in Crematoria (Texas) for about 3 months out of the year. Our incoming city water is quite warm for those months. It will generally be somewhere between 80-85* most of that time because the ground gets so hot and the water gains allot of heat at the water plant before going into a large metal tank which also absorbs heat and it doesn't get below 80* at night...

So does anyone have any bright ideas of reasonable ways to lower the incoming water temp?

FYI we are on the old small 2" water main that was put in back in 1961. The new house next door is on the new plastic watermain that is a direct line to the treatment plant and their water temp is nearly 90*. Ours is 86*.

Piwoslaw · 07-07-22, 01:15 PM

Wow

I never thought about hot the underground water line can get.

Not sure how long a run you have on your property, but maybe laying the main deeper under ground? It would be a bit cooler there, at least until the surrounding earth warms up from the water.
Splitting the main into a few pipes running parallel, at a certain distance from each other, would be better, but the cost would go up.

Another idea would be an underground tank, deep enough to cool the water somewhat, large enough to hold 1-2 days' worth of your water usage. The tank could be air-tight and pressurized, so the water just flows through, without the need for additional pumps.
Not sure whether this might not increase the risk of microbes in the water.

Elcam84 · 07-07-22, 01:24 PM

Yeah once water starts warming up then Legionella starts becoming an issue. Our water for the house is from the city and our house is far the the front and side of the lot which means our line from the house to the water main is only about 20' as the main is on the side of the house.

My thought was that the heatpump water heater guys could make a two tank system. Pull the heat out of the cold side tank and put it into the hot side tank.

Sadly the problem will be made even worse when I put in a water softener and filter as they will be in the garage soaking up even more heat...

My question is what to do they do about it in desert areas. Do they just live with the fact that you will get Legionnaires disease every so often? It's usually an issue in waterheaters that aren't set hot enough but happens in cold water supplies that are not cold enough.

NiHaoMike · 07-08-22, 10:30 PM

City water contains chlorine (nowadays in the form of chloramine, more effective than chlorine gas) to prevent that problem.

u3b3rg33k · 07-13-22, 01:27 AM

how cold do you want it to be? how much water do you need to chill, and how much do you want to spend running it? is this just for drinking water, or are you going to chill water so you can pay to heat it in the water heater later?

also no reason you can't use a thermal storage tank in reverse. run the city water through the HX, chill the mass storage - just make sure the HX is double wall/rated for potable use.

dremd · 08-04-22, 06:01 AM

Wild issue. I’ve never considered this as a potential problem before.
Only things I can think of are mentioned above, but 1) burry pipe significantly deeper (any idea how deep it is now?) 2) use an A/C with a water heat exchanger to pump the heat out.

Elcam84 · 08-08-22, 08:37 PM

Yeah it's a pretty common issue here. It's up to just over 90* now... Short run to the main as well. The main is only a 2" pipe and dates back from 1960 or so.
As for burying it deeper... My 100' well has a water temp of 70* which is right at the correct temp for water at that depth here. So I'd have to dig really deep.

It's really annoying to not have any cold or cool water supply. You don't realize how important it is to have cold water until you don't have it. Fortunately I end up using only cold water at the end of a shower and it's not cold enough to cool off before getting out of the shower.

u3b3rg33k · 08-10-22, 11:19 AM

if you're really set on doing this, off the shelf I'd look at a buffer tank, potable HX, and a pool heat pump/ac, to cool the buffer tank.

jeff5may · 01-15-23, 12:09 PM

Hate to resurrect an old thread, but you could use your cool well water to chill your City water. Just plumb up some sort of heat exchanger between the well and the city water. Preferably after the city water splits between the water heater and the house. Depending mainly on your preferences about conserving well water and running a large heat exchanger versus using more well water and running a smaller heat exchanger, and whether or not you want to have a bulk tank of cool water in reserve, the design would follow your personal preference.

redneck · 05-23-23, 08:37 AM

Quote:

Originally Posted by Elcam84

Yeah it's a pretty common issue here. It's up to just over 90* now... Short run to the main as well. The main is only a 2" pipe and dates back from 1960 or so.

As for burying it deeper... My 100' well has a water temp of 70* which is right at the correct temp for water at that depth here. So I'd have to dig really deep.

It's really annoying to not have any cold or cool water supply. You don't realize how important it is to have cold water until you don't have it. Fortunately I end up using only cold water at the end of a shower and it's not cold enough to cool off before getting out of the shower.

Your answer is right there in bold.

But, no digging required…

Install a “U” shaped pipe inside your well casing along side your existing supply line from your pump and connect it to the city water line.

The “U” shaped pipe will act as a heat sink for the city water.

Just remember that you will need to size the pipe accordingly. 200’ of 3/4” pipe would probably have reduced flow. 1” dia. pipe should be about perfect. Then fully insulate the pipe running from the well to the house.

Do it and report back…😉

>

.

07-06-22, 05:53 PM	#1
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	Methods for cooling incoming city water supply? This is something that is an issue here in Crematoria (Texas) for about 3 months out of the year. Our incoming city water is quite warm for those months. It will generally be somewhere between 80-85* most of that time because the ground gets so hot and the water gains allot of heat at the water plant before going into a large metal tank which also absorbs heat and it doesn't get below 80* at night... So does anyone have any bright ideas of reasonable ways to lower the incoming water temp? FYI we are on the old small 2" water main that was put in back in 1961. The new house next door is on the new plastic watermain that is a direct line to the treatment plant and their water temp is nearly 90. Ours is 86.

07-07-22, 01:15 PM	#2
Piwoslaw Super Moderator Join Date: May 2009 Location: Warsaw, Poland Posts: 964 Thanks: 189 Thanked 111 Times in 87 Posts	Wow I never thought about hot the underground water line can get. Not sure how long a run you have on your property, but maybe laying the main deeper under ground? It would be a bit cooler there, at least until the surrounding earth warms up from the water. Splitting the main into a few pipes running parallel, at a certain distance from each other, would be better, but the cost would go up. Another idea would be an underground tank, deep enough to cool the water somewhat, large enough to hold 1-2 days' worth of your water usage. The tank could be air-tight and pressurized, so the water just flows through, without the need for additional pumps. Not sure whether this might not increase the risk of microbes in the water. __________________ Ecorenovation - the bottomless piggy bank that tries to tame the energy hog.

07-08-22, 10:30 PM	#4
NiHaoMike Supreme EcoRenovator Join Date: Oct 2008 Location: Austin, TX Posts: 1,154 Thanks: 14 Thanked 257 Times in 241 Posts	City water contains chlorine (nowadays in the form of chloramine, more effective than chlorine gas) to prevent that problem. __________________ To my surprise, shortly after Naomi Wu gave me a bit of fame for making good use of solar power, Allie Moore got really jealous of her...

01-15-23, 12:09 PM	#9
jeff5may Supreme EcoRenovator Join Date: Jan 2010 Location: elizabethtown, ky, USA Posts: 2,431 Thanks: 431 Thanked 619 Times in 517 Posts	Hate to resurrect an old thread, but you could use your cool well water to chill your City water. Just plumb up some sort of heat exchanger between the well and the city water. Preferably after the city water splits between the water heater and the house. Depending mainly on your preferences about conserving well water and running a large heat exchanger versus using more well water and running a smaller heat exchanger, and whether or not you want to have a bulk tank of cool water in reserve, the design would follow your personal preference. Last edited by jeff5may; 01-15-23 at 12:54 PM..

07-07-22, 01:24 PM	#3
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	Yeah once water starts warming up then Legionella starts becoming an issue. Our water for the house is from the city and our house is far the the front and side of the lot which means our line from the house to the water main is only about 20' as the main is on the side of the house. My thought was that the heatpump water heater guys could make a two tank system. Pull the heat out of the cold side tank and put it into the hot side tank. Sadly the problem will be made even worse when I put in a water softener and filter as they will be in the garage soaking up even more heat... My question is what to do they do about it in desert areas. Do they just live with the fact that you will get Legionnaires disease every so often? It's usually an issue in waterheaters that aren't set hot enough but happens in cold water supplies that are not cold enough.

07-13-22, 01:27 AM	#5
u3b3rg33k Apprentice EcoRenovator Join Date: Mar 2018 Location: Rustbelt, USA Posts: 114 Thanks: 5 Thanked 10 Times in 9 Posts	how cold do you want it to be? how much water do you need to chill, and how much do you want to spend running it? is this just for drinking water, or are you going to chill water so you can pay to heat it in the water heater later? also no reason you can't use a thermal storage tank in reverse. run the city water through the HX, chill the mass storage - just make sure the HX is double wall/rated for potable use.

08-04-22, 06:01 AM	#6
dremd Need More Eco Join Date: Sep 2008 Location: Scott, La Posts: 172 Thanks: 2 Thanked 6 Times in 6 Posts	Wild issue. I’ve never considered this as a potential problem before. Only things I can think of are mentioned above, but 1) burry pipe significantly deeper (any idea how deep it is now?) 2) use an A/C with a water heat exchanger to pump the heat out.

08-08-22, 08:37 PM	#7
Elcam84 Apprentice EcoRenovator Join Date: Jun 2013 Location: TX Posts: 275 Thanks: 2 Thanked 31 Times in 24 Posts	Yeah it's a pretty common issue here. It's up to just over 90* now... Short run to the main as well. The main is only a 2" pipe and dates back from 1960 or so. As for burying it deeper... My 100' well has a water temp of 70* which is right at the correct temp for water at that depth here. So I'd have to dig really deep. It's really annoying to not have any cold or cool water supply. You don't realize how important it is to have cold water until you don't have it. Fortunately I end up using only cold water at the end of a shower and it's not cold enough to cool off before getting out of the shower.

08-10-22, 11:19 AM	#8
u3b3rg33k Apprentice EcoRenovator Join Date: Mar 2018 Location: Rustbelt, USA Posts: 114 Thanks: 5 Thanked 10 Times in 9 Posts	if you're really set on doing this, off the shelf I'd look at a buffer tank, potable HX, and a pool heat pump/ac, to cool the buffer tank.