ECOAC: World’s first desktop thermoelectric cooler/heater - Page 1
Forum section: electronics / general

author: PsychoBoy
author_rank: Contributor
timestamp: August 12, 2019, 09:57:25 pm
content: Hi everyone, so I stumbled upon this exciting kickstarter campaign:https://www.kickstarter.com/projects/1841842840/ecoac-worlds-first-desktop-thermoelectric-cooler-hAt first sounds so promising:"Eco-friendly cooling and heating using recyclable water instead of GWP refrigerants as coolant. "But how this is exactly eco-friendly? Will it even be able to cool down the room?I highly doubt because it has only 60W of cooling capacity.Don't you guys also feel that those innovative projects with the same look and feel are made by the same people? Even voice actress sounds the sameBTW. A built-in bluetooth speaker? wtf

author: barry14
author_rank: Regular Contributor
timestamp: August 12, 2019, 10:42:47 pm
content: A cooling capacity of 60 watts is equivalent to about 200 BTU/hr. Even a small window mounted room air conditioner is rated at 5000 BTU/hr. Thus you can't expect this device to effective cool even the smallest room. As far as heat goes, it claims 100 watts which is also very small and achievable with a 100 watt incandescent bulb which will also provide light.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 13, 2019, 08:54:59 pm
content: Phrases like "microclimate" and "immediate surroundings" mean, it blows slightly colder air, which, when directed at your skin, would do a bit better job at cooling you down than blowing the hot ambient air with a standard fan. It's not even supposed to reduce the room temperature.Using a water tank allows you to pour the heated water out, preventing it fromheating upthe room. A big part of the heat goes down the drain. This is kinda meaningful since the efficiency of Peltiers totally suck.It's not a totally bad idea, nor a scam, it makes a tiny bit of sense in a very limited meaning. It's easy to see people failing to understand what the product is, and marketing could get carried away and promise too much.A point of comparison: At least over here in Finland, almost every store sells actual scam coolers every summer, and people buy them, in large numbers. These are simply humidifiers, the exact opposite of what you need here in summer. In very dry and hot climates, you can measure a drop in temperature using such humidifiers, and their marketing is based on this fact. In reality, they make the moist, warm air even more moist, and even more difficult to be in. They instruct you to add cooled water and ice cubes from your freezer to perform slightly better; you still have the moisture problem, and now you are just moving the heat to your kitchen (or wherever your freezer resides in), and adding the losses of the freezer.It seems to me this product is clearly inspired by such scams, kind of solving both issues mentioned. It still won't cool the room, but at least it won't make it worse, and should give a nice cool breeze on your skin. An alternative to a good old fan. Still, the cooling power is probably too small to make a big difference to a fan. I could consider DIYing such a gadget with more power, for fun.The "ecofriendliness" due to lack of refrigerants is of course a red herring. Using refrigerants would allow approximately 5-8 times better efficiency than a Peltier, reducing the power consumption, and hence CO2 emissions by 5-8x. There are modern refrigerants with way less than 1000 times of equivalent greenhouse effect of CO2; also they are very well recycled due to legislation, has been for decades. So only a small fraction ends up in the atmosphere.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 13, 2019, 10:53:05 pm
content: As far as I've seen from the description, it's basically a Peltier module, a fan and some kind of watercooling system for the Peltier module. It will still blow hot air out somewhere. How the hell do you design a watercooling system that doesn't blow hot air out? I need to be enlightened. Heat must be dissipated somewhere. The watercooling will just 1/ be a bit more efficient to cool the module down and 2/ will delay heating a bit due to inertia, but with a small volume of water, it will only be like a couple minutes maybe. To delay ambient heating for a few hours it would probably take a huge, and well isolated tank with tens or even hundreds of liters of water.I don't get it.

author: Cyberdragon
author_rank: Super Contributor
timestamp: August 13, 2019, 11:43:38 pm
content: Or you could just use direct evaporator cooling and get the same mediocre results.

author: Siwastaja
author_rank: Super Contributor
timestamp: August 14, 2019, 05:07:52 am
content: Quote from: SiliconWizard on August 13, 2019, 10:53:05 pmThe idea is you pour the heated water down the drain, I guess. (With added greenwash terminology like "use it to water your plants".)Water has specific heat of 4.2 kJ/(kg*K). 1.7 liters stores 7.14 kJ/K, i.e. 7.14 kWs/K. Assuming 20 degC temperature rise on water, that's 143 kWs. At (168+60)W (input power and Peltier heat transfer) dissipated into the water, such temperature rise is seen after 143000 Ws / 228W = 10 minutes.So you get up every 10 minutes to go and drain the water. Fun, huh?

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 14, 2019, 01:26:24 pm
content: Quote from: Siwastaja on August 14, 2019, 05:07:52 amYeah, a few minutes as I guessed.But they claim the big advantage is that you don't have to fill this in constantly. You do. 10 minutes? Good lord. Even a lousy evaporator thing will last longer than that on a single refill.And then you have to get rid of the hot water every time. It will probably be full of bacteria pretty fast unless you constantly wash the tank, so recycling the water, maybe not. Nice.

author: Eldoran
author_rank: Newbie
timestamp: August 15, 2019, 06:24:31 pm
content: Looks like I'll need about ten just to offset the heat generated by my PC and myself. But if it will need me to refill all of them every ten minutes, it's a full time job.