The best way to keep an office cool in the hot summer

[pinball1970]

TL;DR Summary

Large office, no AC, uncomfortably hot do we open all the windows or not?

Rectangular office accommodates 10 people, two doors and one wall has windows the full length of the room.
My office is within, no windows and no direct sunlight there.
The temperature went from 20C at 8am to 25C by 3pm.
Similar temp in the main office.
All windows were open so my thinking is the office is heating via convection.
So no air, hot, sticky/humid and opening the windows just makes it worse, my idea, the other occupants disagree.
No direct sunlight so not much greenhouse effect. Temp here is now 19C predicting to rise to 26C by 4pm
Windows already open.... (8.30am)
I would suggest they are shut before midday 23C, predicted by thenEDIT. Humidity 90% wind is 1mph.

https://www.metoffice.gov.uk/weather/forecast/gcw824kcj#?date=2023-09-08

Just to add some context.

I know posters have been citing 100F plus temperatures so my discomfort at mid 70sF seems trivial.

I appreciate how uncomfortable that must be.

However, The UK has a temperate climate, hot but not too hot in the summer cold but not too cold in the winter with rain throughout the year.

Nothing too drastic so we wilt in hot weather. (23C plus)

If it snows and sticks this is quite a thing, we are not great in the snow either.

 

[Drakkith]

Hard to say. Closing the windows could retain all that heat created by people, computers, etc. Do you have a floor/desk fan? Just some airflow would probably do wonders for you.

Though I wish I could trade you weather right now. Nearly 39C outside today, and we just had a month or more of nearly nonstop of 39-41 C weather up until last week. We lost power for 36 hours back in June and it was around 31C inside my house. At night.

 

[pinball1970]

Hard to say. Closing the windows could retain all that heat created by people, computers, etc. Do you have a floor/desk fan? Just some airflow would probably do wonders for you.

Though I wish I could trade you weather right now. Nearly 39C outside today, and we just had a month or more of nearly nonstop of 39-41 C weather up until last week. We lost power for 36 hours back in June and it was around 31C inside my house. At night.

The computers are quite cool, currently 6 occupants main office with me in my office.

It is not too bad right now but it is only 9.49am

39C is crazy, I do not know how people function in that kind of heat.

Anything over 23C at night is uncomfortable.

2022 was the hottest on record for the UK hitting 40C in Lincolnshire, and 36C up here (Northwest)

That was unbearable.

 

[Drakkith]

39C is crazy, I do not know how people function in that kind of heat.

Partially adaptation (for those who actually go out regularly in that kind of heat), plus drinking lots of fluids and staying in the shade as much as we can. Most people stay in the air conditioned interiors if at all possible. I grew up just a little south of Dallas, Texas, around 32 degrees north in latitude, with no central AC in our house and just a box fan in the window at night. In the summer daytime we would often play outside in the 95+ degree weather (35+ C). Lots of drinking out of the backyard garden hose!

 

[gmax137]

Do you have a floor/desk fan? Just some airflow would probably do wonders for you.

I know the OP is asking about the windows but this^^^ Before AC everyone used fans.

 

[pinball1970]

I know the OP is asking about the windows but this^^^ Before AC everyone used fans.

The girls have already claimed the desk fans. When we are at thermal equilibrium with the outside it feels like we are blowing uncomfortable hot humid air from here to there.
I hit 25C again, hot humid and totally avoidable.

https://amp.theguardian.com/world/s...st-way-to-keep-your-home-cool-in-the-heatwave

 

[Drakkith]

The girls have already claimed the desk fans.

Fans are cheap. Grab a desk or floor fan from your fan outlet of choice and let his royal airness wash over you.

As for whether to open the windows or leave them closed, that I can't help you with. However, a single AC window unit might do your office wonders. Just make sure you get the power and plug requirements right. Don't want to blow a fuse because you bought one that draws 50% more current than the circuit can handle.

 

[Lnewqban]

Rectangular office accommodates 10 people, two doors and one wall has windows the full length of the room.
My office is within, no windows and no direct sunlight there.

It would be ideal to mechanically exhaust as much interior hot-humid air as possible, making the make-up air sweep the length of the office from inlet to outlet.

The killer is the film of stagnant air located next to everyone's skin, which prevents its drying and cooling.
Turbulent air stream can break and remove those films.

You could achieve a good breeze constantly moving from one end of the office to the other, by selecting one or more suitable window fan, and by eliminating air infiltrations between inlet and outlet (closing most windows, but using the extreme ones).

Avoid blowing-in fans, which add the heat of the motor to the interior air and which airstream can only reach a few feet away from it.

Please, see:
https://sanbornsac.com/how-to-improve-air-circulation/

https://www.bigrentz.com/blog/air-change-rates

https://www.google.com/search?q=win...mg&ei=Otn7ZPOwKMHK5NoPm4KGUA&bih=706&biw=1056

 

[jrmichler]

All windows were open so my thinking is the office is heating via convection.
So no air, hot, sticky/humid and opening the windows just makes it worse, my idea, the other occupants disagree.

You can help settle the arguments by getting an indoor-outdoor thermometer and proposing a policy: If outside temperature is better than inside temperature, then open windows. Otherwise, close windows. Image of typical thermometer randomly grabbed from internet: