Tank thermostat

[Tim Lamb]

Curious! Said Alice.

Idly turning the setting dial on a *just out of the box* Danfoss cylinder thermostat I could clearly hear the switch changing over.

The curious bit is that my office temperature might be 23 deg. C whereas the temperature setting on the stat. is *on* 42 and *off* 48!

The settable range is 30 to 90 so not out of range. I know it is common to have a resistor across the circuit to reduce hysteresis but don't see this being explained by lack of power.

Any ideas?

I plan a call to Danfoss technical dept. on Monday.

[Dave Liquorice]

The two redundant Honeywell tank stats I have here click at about the right place for the room temp.

I don't think tank stats have heater resistors, plenty of heat available from the socking great, water filled, copper lump it's attached to. A room stat with just low thermal capacity air to transport heat to the bimetal strip is rather different.

[ARW]

That's not an office - thats a sauna!

[Tim Lamb]

In message , ARW writes

You must try coming South in the Summer:-)

Currently 73 deg. F by the antique stick barometer (so old that the other scale is Reau.. : blood heat 30 deg.) Office 21.6 deg. C

>

[harryagain]

You will need to let the thing achieve room temperature & try the experiment again.

[Tim Lamb]

In message , harryagain writes

It has sat in my office for more than 24 hours. At risk of scandalising Adam, the temperature has crept up to 24.3 deg. C The stat. on/off points are now 43 and 48 deg. C

I may well be told the bi-metallic strip is optimised at 65C in which case they should not have pretended to calibrate in equal intervals.

I suppose it is possibly a Screwfix Chinese *knock off*. If so, they have gone to a lot of trouble printing Danfoss all over the fancy box it came in.

>

[Vir Campestris]

It's 23 in here now, at 22:00. And I've had the door open most of the day to dump heat.

Andy

[Dave Liquorice]

And what temperature was it outside when you had the door open? You ain't going to dump much heat if outside isn't a reasonable amount cooler...

If it's warmer outside you have the opposite effect. The air flow might make it feel better but overall the inside will be warming up. Best to keep southish side windows/doors closed and curtains drawn. Northish might be OK to open but that does depend on the shade temperature relative to indoors.

Evening, overnight to early morning once (if) the heat of the day has gone is the time to open up to let the cooler air in to cool the building before the next day.

[Mike Tomlinson]

In article , ARW writes

The workplace thermometer I'm looking at now defines "Comfort Zone" as between 16 and 24 deg.

It's reading 22 now which I would call comfortable (wearing a T shirt).

[Andrew Gabriel]

16 used to be a minimum working temperature in some work environments. It happens to be the melting/freezing point of glacial acetic acid, and we used to complain in chemistry lessons when the jar of glacial acetic acid on the shelf was frozen!

Comfort is based much more on the wet-bulb temperature (and wind-chill and exertion), and although it's been warm over the last day, it hasn't been very high humidity.

[Dave Liquorice]

Bit broad, 16 I'd find a bit cool just sat at a computer. 24 decidely hot if physicaly active.

Heating briefly kicked in at 1600 when the set point goes from 18.5 to 20, it's 20.5 now fine in a light polo shirt. Quite nice outside

15 C, F3 wind so it "feels like" about 10 C, yep comfortable.

[Vir Campestris]

Well, today the rain-all-day they forecast yesterday morning didn't turn up until 1900, and I've been out so the door has been shut all day. It was 30.

The only windows and doors are on the north (and slightly west) end.

Andy

[Dave Liquorice]

Sounds like a bit of an odd house. Even terraces have windows/doors at opposite compass points...

[Vir Campestris]

Not a house. Something like this:

The house is another matter, but she won't let me keep all my stuff in there.

Andy