Questions on dry hopping

Hello all! Currently my gal and I have 5 gallons of an ipa in our fermentation bucket. We want to pull about a gallon out at bottling time and put it in a separate fermentor to dry hop it to see how it comes out differently from the other 4 gallons. I have a few questions.

First we are having to use a swamp cooler system as the weather in Chicago is hot right now. When we transfer to dry hop do we need to keep that in a swamp cooler as well! Or since the yeast will be done at this time can we leave it at our ac'ed room temp?

Second I have read that you should use hops with a 6 alpha rating or down but many dry hop you read about have higher alpha levels than that. Any thoughts on this?

Last I've read about three days is fine but it seems others do much longer. Is there a good gauge to use when dry hopping? Does it depend on the alpha level?

Thanks all!

I wouldn't worry too much about the heat, just keep it around room temp. Your bigger problem is going to be the introduction of air into the beer. Try to get a container that you can seal up with almost no extra space after the hops and beer have been introduced.

On the hops, use any hop you like and dry hop for about 7 days.

+1 on everything DonMagee said. As for choosing the hops, what aroma are you trying to get? You need to decide that, then look into what hops to choose. For American IPAs, many like Cascade, Centennial, Amarillo, Citra, Simcoe, Chinook, and Columbus, but there are a bunch of others you could use depending on what you're going for. As for alpha acids, many of the great aroma hops tend to have lower levels, but some hops traditionally used for bittering have a high level of aromatics as well and work great for dry hopping. Most of the hops I listed above have alpha acids higher than 6 but are great for dry hopping. Again, choose what you want in the aroma and then research some hop profiles a bit. Hope that helps!

Thanks everyone!