Air conditioning

[bigcat]

cooler

It varies a lot, you wont get much result if you do it on a timer.

NT

[Andrew Gabriel]

No they wouldn't because a dehumidifier chucks out loads of heat too.

because is counteracts the drop in humidity with a rise in temperature.

A/C works very well even if it doesn't drop the temperature, as it does drop the humidy very significantly.

They do indeed make things worse, although they often don't work at all in UK climate as it's too humid. They work very well in dry heat, which we never get.

RH governs you body's ability to cool itself, which is actually much more important than the temperature.

[Pete C]

No, built horizontally into the hatch...

IME the fans aren't that noisy on low, they could always be switched off for a while and there would be some convection through the hatch instead. What sort of set up do you have, is it switched off at night?

Not easy to add crossflow ventilation I would have thought.

Not easy for everybody. Using a timer or doing it manually would give some idea of how well it works and so whether it's worth making a differential stat.

cheers, Pete.

[bigcat]

temperature.

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5 mistakes

NT

[bigcat]

ok, have it your way, but dont blame me when you realise why it wasnt such a great idea.

theyre inadequate on full, on low just a waste of time.

really useful

even less than useless

Here I've got none of this in yet, cant wait to do it again, but priorities etc.

What I used was

1. 24 hour indoor/outdoor temp whatnot
2. Passive crossflow venting on top floor
3. Plus 12" Forced venting for extra fast cooldown when nedeed
4. full house wall shading

1,2,3 got me 4-10C of improvement.

4 I dont know, as there was not enough monitoring to record temp changes.

At a previous addr I also used evaporative cooling which helps a bit more, and high power fanning, which is remarkably effective, but a bit impractical. 1.4kW of fan per room feels lovely and cool, even at >30C, but is damn noisy, guzzles power, and you can forget even owning paperwork, let alone doing it. I spose one advantage is no need for dusting :)

This time I'm thinking of going for upstairs crossflow first, then hopefully earth pipe or loft ventilation to give complete cool all summer on minimal energy use.

I'm not sure what problem you see. It is simple to add locks to sash windows so they sit 2" open. Open front and back, and you get cross ventilation. It will often be necessary to add door grills as well.

no. IIRC Redrok.com had some of the simplest designs.

As I explained Pete, it is as good as useless, but do as you wish. I did try it.

NT

[Pete C]

They'll give you *far* more air flow than an open window alone on a still day/night, probably 1 or 2 m3/s

Sounds good but it's worth doing some calculations on the earth pipe and crossflow fans, otherwise they might end up using more energy than a decent A/C. What sort of kW in/out and temp drop/airflow do you expect from the earth pipe?

OK how would you ventilate the loft or would you leave it as is? I would have thought a good route is in through the hatch and out under the eaves, hence a fan in the hatch. There are better ways of doing it but would require work to the roof.

cheers, Pete.