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by JackMorgan 616 days ago
I was just about to buy almost this exact setup! Excellent to see it's effective. I thought I was mad looking into fish tank coolers. I was thinking though skipping the evaporative cooler and going with a compressor model. Quite a bit more expensive but I think it'll be more effective in the humid North East.

I have realized over the years that I need to be seriously cold to sleep well. My health watch always registers a great sleep and recharged "body battery" when I've been almost shivering all night. My partner likes to joke that my body needs "suffering to get fully rested".

These days, I only ever have nightmares when I'm too hot. It's a challenge to stay cool enough to not get them.

I did recently switch mattresses to this Airweave Futon: https://airweave.com/products/futon

It's an amazing product, it helps keep me cool, and is nice and firm, which I need to have a restful sleep without back pain. By far my favorite mattress I've ever used.

The Airweave has reduced my hot nights significantly, and I'm thinking if I can put a cool pad underneath it, I'll be set!

I'm going to have to try this DIY project for sure now!

4 comments

> Compressor

I would think these would be too loud for a comfortable sleep environment.

You could put a small compressor outside and connect a well-insulated hose to pump the refrigerant inside, just like a split system air conditioner. Then the noise in your bedroom will be no worse than the occasional hum of a fridge in the other room.

As someone who lives in a humid climate, I wouldn't even think of using an evaporative cooler anywhere in my home, for any purpose, period. It's either compressors or nothing.

I believe the Eight sleep uses a Peltier cooler. Not terribly efficient, but the ΔT and the load are low (a human body puts out <100W while asleep). Plus, a Peltier can also heat with some supporting electronics.
Does the water need to be that cold? I would think the cooling can be accomplished just by having a large enough water tank and possibly a radiator and fan so that the thermal mass would prevent your body from heating it up for the 8 hours or so you spend on bed.
What room temperature are we talking? I used to think I could not be too cold at night, until recently I lived in a place that was seriously cold (basically no insulation). Turns out there is a limit! Room temp would easily drop below 15 degrees, often closer to 10!
I definitely sleep really good with a thin sheet down to 60F/15C. Below that, yeah I'll put in a blanket.

For reference in 2022 I winter hiked the southern half of the AT, and it was below freezing every night for months. I did have a sleeping bag, but I slept great! I curse/blame my Scandinavian genes. Too pale for the equatorial sun and sleep like a furnace all night.

Sounds like Australia in winter, further inland and south...
> My health watch always registers a great sleep and recharged "body battery" when I've been almost shivering all night.

Would you mind sharing which watch (model) offers this? I guess a Garmin of some sort?

I think most Garmins have it. I have a Venu 3 and am very happy with it, the killer feature for me is it getting over a week of battery life on a single charge vs the apple watch with it's 20 hours.
I see the same results on both the Vivosmart 4 and the original Instinct. Both Garmin.
A reviewer on reddit complained that the airweave wore out after a year, which is disappointing given the price. How long have you had it?
I would be disappointed as well!

I got it a year ago, still feels like new. However, I got the very thin Japanese futon model, and my partner and I are both under 145lb/65kg so that probably goes a long way. I could definitely see a heavier load compressing the coils permanently.

I did see this on their FAQ page:

"Up to what individual body weight is ideal for an airweave? We have tested our mattresses for individuals up to 220lbs. At this weight or lower, you should expect to use your mattress for 10-15 years. For any individuals above 220lbs you may see body indents and wear sooner"

I also see that the warranty is good for only 3 years for the futon model, which leads me to believe I'll be shopping for a new one in 2 years. That's... Not a long time for the fairly steep price of $2600.

When this wears out, I'll probably go back to a thin cotton futon, that's my second favorite. I only got the Airweave because my last cotton futon got moldy because it's so humid here it never gets to dry out.