Cooling the darkroom

[david b]

What's Humidity (says the guy living in New Mexico).

 

[Dave Miller]

What's Humidity (says the guy living in New Mexico).

It's what we don't get when it's snowing.

 

[david b]

well my new darkroom reaches 85F in the late afternoon so right now I am looking into the cooling/heating/ventilation options.

I just moved my enlargers in last night and I am going insane just looking at them.

 

[Dave Miller]

well my new darkroom reaches 85F in the late afternoon so right now I am looking into the cooling/heating/ventilation options.

I just moved my enlargers in last night and I am going insane just looking at them.

Only 85F; that cold compared to Middle England.

 

[UKJohn]

I had my loft converted to house my dark room, it was triple insulated at the time, and had a velux windows put in, most of the time its pretty comfortable. This past week its about 30 degrees, the insulation works (I think) as the room is at the ambient air temp.

I bought a fan but all that does is blow the warm air around in circles and as the UK only experiences limited excessive warm weather I'm not sure buying an A/C unit at some silly price is justified. Whilst its warm I'll just sit out have a beer, read a book and enjoy the sun. You can soon count on it raining and once the temp drops to about 20 degrees or so I'll be up and running again.

In the meantime I took the opportunity to clean my Nova unit, drain down the archival washer and give that a clean, and had a good general tidy up. I like to be productive between beers and the world cup lol

 

[pentaxuser]

Only 85F; that cold compared to Middle England.

Yes. The around the world temps in Sunday's Observer put London at about 2 degrees C less than Cairo and only about 5 degrees less than Saudi Arabia.

My darkroom was almost 30 last night and was still about the coldest room in the house. That's nearly 90 degrees in old money.

Quiet! Is that a rattler I can hear in the bushes?

pentaxuser

 

[Andy K]

In the yard outside the warehouse it was 32C today.

 

[david b]

Well, the darkroom drops to about 78 in the late evening and morning. But I am lacking ventilation and that is my top priority this week.

 

[FrankB]

At 07:45 in our office it was still 28C left over from the day before. It peaked around 30C.

Thunderstorms are forecast for the next few days and it should be pretty much back to normal by the weekend. In theory...

 

[Dave Miller]

At 07:45 in our office it was still 28C left over from the day before. It peaked around 30C.

Thunderstorms are forecast for the next few days and it should be pretty much back to normal by the weekend. In theory...

That's the three fine days and a -------- rule.

 

[Matt5791]

Pentaxuser - sorry for the delay in reply - the 9000btu unit says it will handle a 20 sq. metre room - which is about 200sq.ft. I donth think you can get smaller than this. My darkroom has a square footage of about 200 - but less volume because it is in the loft and the 9000btu unit is just powerful enough.

There are other factors to consider though - the insulation of the room and also, and this is the most important, setting it going before the room reaches full temperature - much easier to stop it getting hot int he first place as opposed to trying to cool it, and everything in the room, down afterwards.

Matt

 

[Dave Miller]

I've just returned from my local Homebase where they have reduced their 9000 BthU free standing a/c's to £150 to clear.

 

[catem]

Interesting thread - I'm only just realising how hot is was here last week as we were in Venice (lucky us) where by the sound of things, it was cooler. Or maybe similar, but I was expecting it - though with a nice cool breeze.

I'm another 'loft' darkroom person (I wonder how many of us there are?) and was wondering about this very question a couple of weeks back when it was also very hot. This isn't going to go away, is it? I think the summers are set to get hotter and hotter...

Cate

 

[Helen B]

What's with all this recidivist BTU nonsense, huh? Are kilowatts too simple and honest? Well?

 

[Dave Miller]

What's with all this recidivist BTU nonsense, huh? Are kilowatts too simple and honest? Well?

Because that's what it says on the box; British Thermal Units, all 9000 of them.

Definition B.Th.U.
n : a unit of heat equal to the amount of heat required to raise
one pound of water one degree Fahrenheit at one
atmosphere pressure; equivalent to 251.997 calories [syn: British thermal unit, BTU, Btu, B.Th.U.]

If you prefer the Kw units, it equals about 2.6 of those, however that may be misleading to some since the input is only around 1Kw.

 

[Helen B]

Because that's what it says on the box; British Thermal Units, all 9000 of them.

Definition B.Th.U.
n : a unit of heat equal to the amount of heat required to raise
one pound of water one degree Fahrenheit at one
atmosphere pressure; equivalent to 251.997 calories [syn: British thermal unit, BTU, Btu, B.Th.U.]

If you prefer the Kw units, it equals about 2.6 of those, however that may be misleading to some since the input is only around 1Kw.

Sorry Dave, I wasn't being entirely serious, or entirely non-serious for that matter. By giving the cooling power in BTU/hr (not actually BTUs, but that's what almost everybody abbreviates it to) the manufacturer can obscure the fact that it takes 1 kW of electrical power to remove 2.6 kW of heat. It also seems weird to use two entirely different units for power. I can see why - because some people would get confused between cooling and electrical load.

Best,
Helen

 

[Matt5791]

Interesting thread - I'm only just realising how hot is was here last week as we were in Venice (lucky us) where by the sound of things, it was cooler. Or maybe similar, but I was expecting it - though with a nice cool breeze.

I'm another 'loft' darkroom person (I wonder how many of us there are?) and was wondering about this very question a couple of weeks back when it was also very hot. This isn't going to go away, is it? I think the summers are set to get hotter and hotter...

Cate

I recently performed a complete "rebuild" of my loft darkroom and included lots of insulation - the only problem of course, is that duriong a hot day the loft eventually heats up, then, when the evening comes - it stays hot!

Matt

 

[dancqu]

What's with all this recidivist BTU nonsense, huh?
Are kilowatts too simple and honest? Well?

The talk is about cooling. BTU nonsense I agree.
Tons are the true measure of an AC's capacity.

BTW, I've a .4333 Ton Sear's AC ready to install. For partial
small house cooling it may, on a hot day, meet the Kyoto
minimum specified 82 degrees Farenheight. Dan

 

[Helen B]

Dan,

I expect inconsistent, unsystematic units like the ton of refrigeration to be used in the USA, where the beautiful concept of SI units is poorly understood, but much of this discussion is about cooling UK darkrooms and I expect better things.

Best,
Helen Tongue-in-cheek

 

[pentaxuser]

Pentaxuser - sorry for the delay in reply - the 9000btu unit says it will handle a 20 sq. metre room - which is about 200sq.ft. I donth think you can get smaller than this. My darkroom has a square footage of about 200 - but less volume because it is in the loft and the 9000btu unit is just powerful enough.

There are other factors to consider though - the insulation of the room and also, and this is the most important, setting it going before the room reaches full temperature - much easier to stop it getting hot int he first place as opposed to trying to cool it, and everything in the room, down afterwards.

Matt

Thanks Matt. I have been away myself in Dublin and came back tonight. Middle England is decidely cooler now. Pity that 9000btu is the smallest unit. I have about 9-10 sq metres so under half the meterage that the unit can handle. As it quotes capacity in sq metres rather than cubic metres it must assume all rooms to be of a standard height but if it's a normal room a/c then I supposes most rooms are of a standard height.

Dave I am amazed that given the weather and the start of summer that any stockist is reducing the price. A bit like V Putin lowering the price of gas just to shift the stuff if we were to go into another 1962/63 freeze. Defies the laws of supply and demand. Still I am not complaining.

pentaxuser

 

[Dave Miller]

Dave I am amazed that given the weather and the start of summer that any stockist is reducing the price. A bit like V Putin lowering the price of gas just to shift the stuff if we were to go into another 1962/63 freeze. Defies the laws of supply and demand. Still I am not complaining.

pentaxuser

I guess they feel those that were intending to buy, have, so they must attract others. 12,000 BthU units also available at about £200, and splits at £275.

Note: no tons, tonnes, or Kw's available.

As to capacity, the 9,000 BthU unit copes very easily with my darkroom, and I have another in the house that just about kept that under control in last weeks 30C ambient, a 12,000 BthU unit would have been better.

 

[dancqu]

...now I am looking into the cooling/heating/
ventilation options.

Shame so many today have abandoned the area's
ancient indian practice of building Very Thick Adobe
and Stone Walled shelters. Passive heating and
cooling from centuries gone by. Dan