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Old 2020-08-20, 22:17   #34
ewmayer
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Quote:
Originally Posted by Prime95 View Post
At the rumored price, the Radeon VII Pro may be more appealing.
Reminds me, been a while since I did any price-checking on legacy R7s (probably because I am definitively done w/my build-out using same, even if by magic I could score some cheap ones, the electricity bills and you'd-need-to-run-the-AC-even-on-cool-days aspect would make it a no-go) ... usual XFX-R7 link on Amazon shows cheapest used @$1349, but I see a new one one eBay for $999, which is not horrible. And even if no "make offer" option, one can PM the seller to do that ... worst they can do is turn you down.
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Old 2020-08-21, 03:11   #35
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Quote:
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... the electricity bills and you'd-need-to-run-the-AC-even-on-cool-days aspect would make it a no-go ...
Why not duct the hot exhaust to outside?
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Old 2020-08-21, 03:20   #36
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Why not duct the hot exhaust to outside?
Or use it to heat your hot water?
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Old 2020-08-21, 05:11   #37
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Or run a chiller unit in the summer.
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Old 2020-08-21, 06:50   #38
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Quote:
Originally Posted by Xyzzy View Post
Or use it to heat your hot water?
Problem is the amount of heat: air vs water (specific heat capacity, flow, and temperatures), plus any mechanical efforts.
What’s the heat source, air? What’s mass flow and temps of the rejected heat?

Last fiddled with by pinhodecarlos on 2020-08-21 at 06:53
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Old 2020-08-21, 19:34   #39
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Quote:
Originally Posted by retina View Post
Why not duct the hot exhaust to outside?
Believe me, the thought had occurred to me, but I don't own the space, and the required hackery into, say, the exhaust ducting for the clothes dryer would violate my lease. But in order to give the AC a hand on-the-cheap, couple days ago ordered one of these. Where I live is generally a dry climate, evaporative cooling is definitely a good option.
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Old 2020-08-22, 23:53   #40
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Quote:
Originally Posted by ewmayer View Post
Where I live is generally a dry climate, evaporative cooling is definitely a good option.
You are, of course, aware this doesn't change the enthalpy in a closed system?

Your machines won't notice any difference; humans might actually find it (subjectively) slightly warmer because they can't sweat as quickly.

AC Engineers spend a lot of time learning about the difference between dry bulb and web bulb sensors...
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Old 2020-08-22, 23:56   #41
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Quote:
Originally Posted by chalsall View Post
... humans might actually find it (subjectively) slightly warmer because they can't sweat as quickly.
I think you mean: humans might actually find it (subjectively) slightly cooler because the sweat evaporates more quickly.

Lower humidity == more comfortable for a human when it is hot.
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Old 2020-08-23, 00:04   #42
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Quote:
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I think you mean: humans might actually find it (subjectively) slightly cooler because the sweat evaporates more quickly.
Incorrect.

The kit ewmayer has ordered from Amazon is basically a bowl of water with a fan. Thus, the kit introduces moisture into the air, reducing the humans' opportunity to add to the vapor pressure of the closed system.
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Old 2020-08-23, 00:06   #43
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Quote:
Originally Posted by chalsall View Post
The kit ewmayer has ordered from Amazon is basically a bowl of water with a fan. Thus, the kit introduces moisture into the air, reducing the humans' opportunity to add to the vapor pressure of the closed system.
Okay, makes sense. Thanks.
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Old 2020-08-23, 00:22   #44
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Quote:
Originally Posted by retina View Post
Okay, makes sense. Thanks.
Please forgive me for this, but I'm "in that mode".

This is similar to the question "Can I cool a room by running a fridge with the door open?

Cold can't be created. Heat can be moved.

Unless there is a route to exhaust heat, a closed system will always get warmer.
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