First off, I live in Phoenix, AZ. This is desert here. I live in an area where people mostly have natural desert landscaping rather than lawns.
Now, this will sound really odd to folks who live elsewhere, but the house I'm in now does not get "cold" water in the summer. I can literally shut off my hot water heater and take a shower just from the cold water coming in from the city water line. The so-called "cold" water temp is somewhere over 110 for most of the summer. It's fine for most of the rest of the year, just not from May thru Sept.
I've lived in different parts of the city throughout my life, and this is the hottest "cold" water I've ever had to deal with. I think a big part of it is because the ground in this area is quite rocky and sandy, not much solid dirt. And it's dry as a bone.
Where you've got a water main running under yards that have lawns that are watered regularly, the water seeps into the ground and cools the ground and whatever pipes are there. Hardly anybody in this area has lawns, certainly nobody along the route where my water main comes from.
Short of putting a 50 gallon water cooler into a fridge (the opposite of a water heater), I'm wondering if anybody has any ideas about how I might rig up something that could cool the water coming into the house by 20-30 degrees?
============================================
UPDATED 12/10/22
So I forgot about this post and just stumbled upon it again, although I haven't solved the problem yet. It's now winter in Phoenix, so I need some hot water mixed into the cold so it's comfortable. We actually get cold water from the tap from Sep thru May!
Most of the replies seem to be from people who think what I'm saying is as unbelievable as you telling me that you have to worry about water pipes in your walls freezing up. A "freeze" warning here means we have to put sheets over some of our shrubbery for the night. Nobody's pipes freeze here. Are you sure you don't have a refrigerant leak in your A/C somewhere? Trust me, the "cold" tap water from the city has been measured at 112º at times in my area. And the outdoor temps really do get as high as 125º here in the summer!
Anyway, I've come up with this working idea and I'm curious what sort of mechanical ideas you can think of. (I'm a software geek, not much good with this kind of thing.) If I'd be better off making a new post for this, let me know.
I'm thinking of getting something like this from Amazon or Home Depot: Rain Bird T63-500S Drip Irrigation 1/2" (0.634" OD) Blank Distribution Tubing, 500'
By my calculations, a coil of that should hold about 8 gallons of water that would weigh 67 lbs. If I were to build some kind of frame to simply expose it to the air, perhaps hanging from the ceiling above the tub, it would settle to an ambient temp of around 85º. I use a 1 GPM shower head. Using a splitter that can let me send some of the water coming to the shower head into this coil, then mixing it back into the original water flow, could reduce the temp to around 95 degrees for at least 10 minutes, which is about how long it takes me to shower. Worst case, I'd get 8 minutes of a nice cool 85º shower before it went back to "almost scalding hot". :)
What's the best way to suspend 500' of tubing like this from the ceiling with enough space between the coils to allow air to flow? The space is above a normal sized porcelain over metal tub. Would you just hang it from the ceiling joists? or maybe put some metal poles in the corners to support it? I'd be worried about it sagging in the middle or just falling down. In the cooler months, I can drain it since it's not needed.
Also, the tub is on the most exterior part of the wall, and there's no crawl space above it in the attic. So getting up there to do anything is a non-starter short of tearing the roof off.
NOTE: this is not a problem unique to my house or my street. Most restaurants and commercial properties that do not run their cold water lines through their chiller system will have "cold" tap water that's between 95 and 100 degrees. I don't know where folks think it's supposed to get cooled down when the ambient temps outside are well over 100, the ground is mostly covered by cement, asphalt, and bricks/blocks, and underneath is colichi, sand, and clay. We get rain during the monsoon from early July thru Sept, and it's mostly at night. It does not soak into the ground, but mostly runs off. After a rare afternoon rain storm, the ground is dry in an hour.
It's clear that most people who don't live here cannot comprehend water coming out of the "cold" water tap at nearly 100 degrees. I cannot comprehend how anybody lived here before A/C was invented!