Hacker News Reader

Comment by Sprakle | Hacker News Reader

This was a time me and my partner spent far too much effort building contraptions to try and stay cool. Sucking colder air from the apartment hallways, converting a single-hose portable A/C into a dual, and others.

But an especially effective project was an experiment to determine exactly what window covering would reduce heating from direct sunlight the most. We could only cover the inside of windows, and I had assumed aluminum foil would work best, but wasn’t sure.

I set up a test of various materials and stuck them to my window with a thermoprobe and some insulation. I tested printer paper, various foils, and plastics.

Plain old white printer ended up performing the best, and aluminum foil being significantly worse. Best part about paper was it still let a lot of visible light in, while reflecting IR.

Hope this helps someone a summer heats up again!

View on HN

I have 3 large skylights which cause the rooms they are in to get very warm in the evening when it’s sunny. I used the Gila window film that is designed to block heat and UV but allow light through. Though somewhat expensive at around $50/roll to cover 2 skylights, it works extremely well and I wish I had used the film when I first moved in. A huge difference in temperature though I don’t have the empirical numbers. The film is adhesive and requires you to do some acrobatics to apply upside down in a skylight but very doable with a helper. It should be removable with a hair dryer.

During the heatwave I set up an evaporative cooling system by hanging wet sheets in front of open windows on one side of the house.

I had a cool draft running through the house, and out open windows on the other side.

During the worst part of the heatwave I was re-soaking the sheets every 15 minutes, which was a hassle, but otherwise it worked well, I was able to bring the room temperature down by about 10°c.

>> converting a single-hose portable A/C into a dual

Could you expand on that ? Did you manage to get an improvement of efficiency ? What model of A/C were you using ? Thanks

Many people have tried, https://www.google.com/search?q=convert+1-hose+to+2-hose+ac

It probably helps quite a bit, especially when a lot hotter outside than in. (But that's often not the case where I live south of Seattle.) But when I move to IL, I'm thinking mini-split is much easier solution for 1-2 room apt.

As someone who also did the dual-hose conversion.

For some background, you probably know that the AC works by sucking in air and then outputting one stream that's hotter and one stream that's colder. The cold air is blown into the room and the hot air is ventilated out the hose. The problem now is, that the hot air you blow out of the room creates a vacuum and in turn sucks in hot air from the outside. So you constantly take some of the nice cool air of your room and heat it up and blow it out of the building. The dual hose setup instead takes air from outside for the heating up part.

The dual-hose setup should go in tandem with a well isolated window insert. For my mod, I simply taped a cardboard box to the inlet side of the AC unit and created a second opening into the polycarbonate plate covering the window opening.

> Did you manage to get an improvement of efficiency?

Yes, definately. I didn't do any scientific measurement, but after the mod, my workspace did get a lot cooler than before.

> What model of A/C were you using ? De Longhi Pinguino PAC N81

not op but was in same situation for few years as in my region A/C is somehow luxury and a lot of landlords don't mount them.

the issue with portable A/C is that most of the units needs to stay inside apartment, the cooling happens by compression/decompression of coolant, which produces heat and cold. so the A/C unit is producing additional heat that it needs to chill, which makes it inefficient. also these units are loud as fuck, most of them above 65dB.

so if you are in need, look for units that have the ability to channel cold air to the house from outside. otherwise you should always avoid portable A/C as it is really inefficient.

here's better explanation: https://www.youtube.com/watch?v=_-mBeYC2KGc

Reply on news.ycombinator.com