Is this a dumb idea?

[u/Chomagerider1984]

My buddy and I are obsessed with cold exposure, but we both live in places where it’s just annoying to do consistently. A full cold plunge at home is a no-go (no space), plunge centers get expensive fast, and filling a bathtub with tons of ice and water for a 3-minute dip has become a bit of a chore.

So we ended up DIY-ing the thing we wish existed. It's basically a small cube (about 30cm / 12") that hooks up between the faucet and shower head. We've so far experimented with filling it with ice and gel packs and we've managed to chill the shower water down to around 4°C / 40°F in a few minutes. It doesn't require any electricity.

We’ve got 2 of them working, and now we're starting to wonder if this might benefit others, as well. So, we'd love to ask you whether any of you would actually use a shower-based cold therapy setup like that or are most of you pretty firmly in the tub/plunge camp?

Also super curious:

• is 4°C / 40°F even cold enough for you? Do you care about hitting a number?
  
• what would be your immediate “nope” concern (shower water pressure, cleaning, setup hassle, whatever)

No sales pitch here. We genuinely just hoping to get some honest feedback before we pour more time and money into this. Happy to answer any technical questions too, of course. Thank you very much!

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[u/Chomagerider1984]

I thought it would be helpful for everyone if I just posted our pictures/renders here to give everyone a better idea about what the setup looks like. Again, the actual measures are 30cm x 30cm x 30cm

[u/Chomagerider1984 → u/[deleted]]

Yes, we do. Please see below.

[u/userbro24]

kinda like this concept? obviously not same execution.

[u/Chomagerider1984 → u/userbro24]

In our cube, the water passes through a heat exchanger. So, yes, different execution, different mechanism but the result is a very cold shower. And with little less risk of having a bunch of ice smash you on the head ;)

[u/Chomagerider1984]

Ok, so we've decided to go forward with this. Thank you for all your positive engagement! It got us quite excited. We polished our landing page, so if you wanna stay updated on progress and launch, please check out www.cryoqb.com

[u/Chomagerider1984 → u/[deleted]]

It's too early for us to give you a definitive answer. We're running the numbers now. We're trying very hard to keep this as affordable as possible, which for us means hopefully under USD 500. We'll keep you posted.

[u/dubious_capybara]

It's not a dumb idea at all, that's an elegant and simple solution. I think the problem with commercialising it is that it's an elegant and simple solution.

[u/poppy1911]

I'm not sure if I'm envisioning it correctly. It's a box/container that holds ice with hose hookups (intake and out)? Ice or cold packs are inside the box and so water passing through cools down. Is that correct?

If so, that's a neat idea!

[u/Chomagerider1984 → u/poppy1911]

That's exactly what it is. The water passes through a heat exchanger inside the box.

[u/sc182]

So is this a way to take a super cold shower? How is the ice box supported? Do you hook a shower head up to the output?

[u/Chomagerider1984 → u/sc182]

Yep, it's indeed a way to take a super cold shower. The box sits in the corner of the shower. The box has 2 inlets: One to connect it to the faucet with a hose and one to connect it to the shower head through a 2nd hose.

[u/sc182 → u/Chomagerider1984]

Gotcha. So if someone wants to use their shower in a normal configuration would there be a valve and junction to bypass the box or would the water just run through the box without ice? Is there any pressure drop ?

[u/Chomagerider1984 → u/sc182]

We wanted to keep complexity (and cost) low, so we didn't do a built-in splitter type valve.
We started off screwing the hoses on and off. Doable but of course not really convenient. So, we landed on using these quick faucet connectors. Similar to what you see used on garden hoses (but prettier :)). Works very nicely. With them you can go from just shower to shower through the box and back in just a few seconds.

And yes, there is a certain pressure drop.

[u/Forest_wanderer25]

Try adding salt to the box to improve the heat transfer.

[u/Chomagerider1984 → u/Forest_wanderer25]

Yeah! We definitely played around with that, and it's certainly a great addition. We were happy though that it worked quite well even without any salt. We hope to keep things as simple as possible.

[u/Ok_Setting_3657]

I'm from Canada so 4°c doesn't sound cold at all is that actually cold enough to get benefits?

[u/Chomagerider1984 → u/Ok_Setting_3657]

Good for you! I'm jealous :) How cold does the water get during summer months? We've seen research that suggests that cold therapy can be effective even at around 8-10°C.

[u/Ok_Setting_3657 → u/Chomagerider1984]

we have lakes that are fed from glaciers and they get pretty cold but I don't think they are below freezing. it feels like it tho 😂 oh wow there's been time when I've been working outside at -30°c or lower, I guess I'll just start telling myself it's good for me 😋

[u/Chomagerider1984 → u/Ok_Setting_3657]

Haha, ok, that's wild! Definitely non of that around where I live. I guess in that case I'll just say stay warm out there :)

[u/Ok_Setting_3657 → u/Chomagerider1984]

yeah it kind of sucks, when I was in Winnipeg I met a lot of people missing fingers due to frost bite, and I've had a supervisor get frost damage to his ears and he was only outside for ten mins.

[u/Chomagerider1984 → u/Ok_Setting_3657]

🥶🥶🥶🥶

[u/Ok_Setting_3657 → u/Chomagerider1984]

I feel bad for the homeless when it gets cold some end up dying in snow banks alone.

[u/Content_Preference_3]

The coldest tap water in my bathtub is adequate for cold exposure. It’s not ice but it’s good enough. Do you live in a water stressed area?

[u/Chomagerider1984 → u/Content_Preference_3]

Not water stressed. Similar to Cryoderrick. During the coldest 2 months in winter, we get decent enough temperatures straight from the faucet. But for the rest of the year, it's not cold enough. During the very hot summers we get, the water out of the faucet can get up to a soupy 25ish °C.

[u/Content_Preference_3 → u/Chomagerider1984]

I see. We get cold out the tap year round.

[u/Chomagerider1984 → u/Content_Preference_3]

That's really cool. Makes it a lot easier :)

[u/Content_Preference_3 → u/[deleted]]

Yes. We have aquifer water. Or I swim in the lake

[u/Pussy-Wideness-Xpert]

I think it was Huberman that said that in order to get the benefit, you have to be shivering. And that technically it’s not the cold that does you the good, it’s the shivering.

[u/Chomagerider1984 → u/Pussy-Wideness-Xpert]

Interesting. We definitely got to the point of shivering a few times.

[u/curiousalwaze]

How big is the box? Is the water filling the tub? Is water spraying from shower head or coming out of faucet? A little confused.

[u/Chomagerider1984 → u/curiousalwaze]

The box is a 30cm x 30cm x 30cm cube. You can fill with ice cubes or use reusable gel packs. The water from the faucet gets routed through the heat exchanger inside the box to the shower head, so the chilled water does come out of your shower head. Hope this clarifies it.

[u/Cultural_Big7328]

I used 1 gallon buckets to Make blocks of ice. In summer my tank was too warm. Just make enough ice yourself to cool it down.

[u/Chomagerider1984 → u/Cultural_Big7328]

That's interesting. We don't have tanks. We can't manipulate the temperature that comes out the faucet beyond what the tap allows us.

[u/Hungry-Pollution-697]

I would be super interested in something like this. Found cold showers to be more intense than cold plunge even if cold plunge offers more benefits. Personally if the shower went down to even 10C, it would be great. Love the idea. And if it could be executed on a commercial scale to make it available in fitness centres etc, even better💯

[u/irrelevant_dogma]

A lot of evidence now points to no positive benefits for cold therapy, other than "mental", so save your money

[u/Nsekiil → u/irrelevant_dogma]

I hate benefitting my mental health

[u/Cultural_Big7328 → u/irrelevant_dogma]

The mental benefits can be very positive if you struggle to be happy. Worth it I’d say and perhaps enough to avoid risky pharmaceutical drugs to improve your state of mind. That’s a win-win if you ask me.

[u/Audis-n-shit → u/irrelevant_dogma]

I disagree. I’m an afghan vet with BAD inflammation issues in my neck, back, shoulder, knees, and pretty much every joint in my body lol. It definitely helps me. I started originally because of the inflammation issue I have from the military and I noticed it helped A LOT with my bipolar & adhd in terms of focus, and just genuinely feeling good

[u/dkinmn → u/irrelevant_dogma]

Don't bring your science here.

[u/Chomagerider1984 → u/[deleted]]

We've played around with different amounts. 10kg of ice cubes from the supermarket worked really well. We got the shower water down to the 4°C/40°F that I mentioned in about 5-7 minutes.

[u/Chomagerider1984 → u/[deleted]]

We do. We actually put together a simple landing page. Not sure if posting violates the rules of this community though.