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Joined 1 year ago
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Cake day: June 12th, 2023

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  • People are giving some advice but it doesn’t seem appropriate for an absolute newbie. Here’s what I’d say. Absolutely do not run telnet. Because it’s so insecure and everyone knows that, it’s usually not on by default, and you would have had to start it yourself somehow. It’s unlikely that you did that, but you can check to see.

    If you’re new, you very likely don’t need an SSH server running. Unless you’re logging into that computer remotely, you don’t need it. It’s probably not running, but it’s conceivable that it could run by default. Check to see and disable it if you don’t need remote login.

    If you do need remote login, use SSH and use a very good password. Ideally, you’d need to leave newbie territory and use public-private keys instead of a password. It’s also not a bad idea to use a nonstandard port, instead of 22. That doesn’t beef security much, but many scanners are going to look for 22 and nothing else.



  • I suspect the reasoning here is going to not be obvious so some people so I’ll add a little. Heat pumps are more efficient when there’s a larger difference between where they’re getting heat and where they’re putting it. I’m going to call this difference a gradient, because otherwise later I’ll be saying “differences of differences” which gets confusing. The argument here is that moving heat from compartmentalized 90 degrees server room to outside at 95 degrees with a separate system for the house, moving from 75 degrees to 95 degrees, would be more efficient than a single heat pump moving air from the mixed rooms at 80 degrees to 95 outside.

    The magnitude of that effect would depend on how nonlinear the relationship between efficiency and the gradient is. I’m not very familiar with that. I assume it’s nonlinear, but whether it’s highly nonlinear from a gradient of 5 to a gradient of 20. From here, it’s quite nonlinear from a gradient of 25 to 40, but from 5 to 20 it’s pretty linear: https://www.ecosia.org/images?q=heat pump effeciecy vs temperature gradient#id=598B80C1EB5A721C392964CB7708512FC496B78F

    This also doesn’t consider that these are operated with thermostats. Presumably someone is going to set all of the thermostats to the same temperature, 75 degrees or whatever the preference is. The gradient at which the pumps start will be the same in all cases, and the difference will be in how often the pumps run. There will differences in the average efficiency because of the time difference, but it’s by no means obvious to me that there would be a significant benefit for a typical home. I would want some clear evidence before spending money on this.


  • Heat pumps are great, but what this guy is saying is wrong. Generating heat in the thing you’re trying to cool won’t help save any money no matter the technology.

    Let’s say you were deliberately trying to heat something and cool something else, like a water heater and your home. Then heat pumps are doubly effective. Maybe that’s where the confusion in this comment stems from, but that’s not what’s going on with a data center.