Ceiling fans.

[moonloops]

Still gives a nice cooling breeze regardless of extra heat generated. I've never stood in front of a desktop fan during the summer and thought "My goodness, that's hot!"

Sorry, it's in Merkin degrees F - but shows the problem..

 

[Deleted member 113659]

I totally get it, but on the whole it's still more comforting to have a fan giving a gentle cooling effect than nothing at all.

 

[moonloops]

I totally get it, but on the whole it's still more comforting to have a fan giving a gentle cooling effect than nothing at all.

Cool (pardon the pun)

 

[Deleted96908]

I totally get it, but on the whole it's still more comforting to have a fan giving a gentle cooling effect than nothing at all.

True for most climates Ant - but sometimes, if it's very hot and dry (45c and above) a fan blowing hot ambient can be very uncomfortable. So usually, rather than a straight fan, you'd use something like a Desert Cooler which adds a little water to the air - raising the wet bulb temperature, and in doing so reducing the dry bulb temperature, making it feel cooler. Makes it a bit more sticky but that's not a bad thing when the air is otherwise very dry.

We had very simple home made Desert Coolers in Sudan and Riyadh - a fan blowing through a light gauze which had water trickling over it. Same technique is used industrially in the region, albeit on a much larger scale. Instead of water dripping or being sprayed into an airstream, they'd make water features such as internal fountains - or cascades, where the water coursed over marble slabs, much like a little river breaking its banks. The water would then evaporate, having the effect of cooling the air in the same way desert coolers work. Very effective and picturesque.

T.E. Lawrence apparently used the technique to great effect. He had his servants urinate on his tent whilst another fanned air through the material. Effective but no doubt a little smelly - but then again they did sleep with their camels!

 

[Benzmanc]

Sorry, it's in Merkin degrees F - but shows the problem..

Erm a Merkin is a totally different kettle of........

 

[developer]

Fans don't just blow hot air around - there's some science going on, as I found out when looking at ceiling fans for a music venue we frequent - someone there said "there's no point installing a fan as the air you're blowing round is already hot so it will make no difference" (or something like that).

Here's a short sharp summary and why they do appear to make you feel cool, even in hot rooms:

A fan just circulates the air. Once the air is moving, cooler air from lower in the room can be made to circulate and that is cooling. The moving air over perspiration carries the heat away from the skin and evaporates the perspiration that is cooling.

 

[ChrisEdu]

I'm most disappointed with this thread. Finally, I thought to myself, a group of people that have also developed an appreciation for that part of the room sitting over our heads, going about its business and never being appreciated, unless some famous person happens to have painted a picture, or it falls on the audience in a theatre! But no! How wrong was I? It's a thread about a mechanical device to move/circulate air. Oh well, I'll get my coat and move on! ;D

p.s. Anyone use a potable heat exchange air conditioning unit?

 

[Deleted member 113659]

I'm most disappointed with this thread. Finally, I thought to myself, a group of people that have also developed an appreciation for that part of the room sitting over our heads, going about its business and never being appreciated, unless some famous person happens to have painted a picture, or it falls on the audience in a theatre! But no! How wrong was I? It's a thread about a mechanical device to move/circulate air. Oh well, I'll get my coat and move on! ;D

p.s. Anyone use a potable heat exchange air conditioning unit?

Haha. Fantastic.

 

[ChrisEdu]

Opps! Should have been portable, not potable! Must be all the fumes from the wax!

 

[John]

A fan just circulates the air. Once the air is moving, cooler air from lower in the room can be made to circulate and that is cooling. The moving air over perspiration carries the heat away from the skin and evaporates the perspiration that is cooling.

Yup - and that's what works for us.

I'm well aware of the concept of blowing hot air around which is why I bought the portable back in 2002.

With windows open - eventually the ambient temp drops to a level which is fine.

It's just not that hot in our house enough for anything else.

 

[GordonTarling]

There are a few split system units which you can self install. They are already charged with gas, so you connect up, open the valves and there you go. However, the lines you have installed should really be evacuated and leak tested before the gas is introduced. I installed a split system in my new workshop - cost £400. I then had a local A/C company come and commission it, which was another £100. They also introduced a dye which will help show up any future leaks. Warm in winter and cool in summer now.