On Sun, 29 Jul 2018 14:27:55 +0100, Tim Watts
wrote:

On 29/07/18 14:00, Scott wrote:
On Sun, 29 Jul 2018 13:49:58 +0100, Tim Watts
wrote:

On 29/07/18 12:31, Scott wrote:
On Fri, 27 Jul 2018 09:10:25 +0100, Tim Watts
wrote:

Hi,

Who makes good domestic UPSes these days? Looking for about 500VA (need
to put a power meter in to be sure) and 30 mins runtime.

But it's more about which make and possibly series are any good?

Would like a decent output too (proper sinusoidal).

Sorry, a basic question. Do these devices detract from energy
efficiency? If leaving stuff on stand-by is frowned upon, is a UPS
not even worse?



Don't care

Well, I do. I'm not spending any of my time trying to set up an
energy efficient home only to have it undone by one appliance.

I was hoping for an answer to my question.


Well, yes - to some extent it will add a degree of inefficiency. That's
unavoidable with any UPS.

The question is:

How do you value a small waste cost vs unavailable or possibly damaged
IT equipment due to frequent power losses?

APC's SmartUPS 1000 claims 97% efficiency.

Let's be uncharitable and say a typical UPS is 90% and your IT load is
100W (that's a lot, an HP Microserver Gen8 is quoted at 50W - so I am
adding a switch, modem and HA embedded controller.

Your wastage there would be 10W.

At 15p/unit that is 3.6p/day or £13/year.

In over half the year, that heat is probably not wasted (contributing to
home heating).

If the APC get's better than 95%, halve the above.

It's a very small number in the grand scheme of things.

Thanks very much. This allows me to assess the pros and cons.

My thinking is not to install a UPS since power cuts are very
infrequent here (all supply wiring underground). Also, I have a
dedicated radial circuit for the computer and all circuits have
individual RCBOs so a fault inside the property should not affect the
supply to the computer. I'm not doing anything very out of the
ordinary and Windows 10 generally seems to recover well.