Chillers: What HP to Get?

[Enigma]

I've just been surprised with a one week vacation to Kelowna in August. I am mortified! (Though I tried to hide my horror from hubby)

I figured i would battle out my first summer reefing with fans and bottles of frozen water (to float in the tanks). My 18-year-old son (my critter sitter) can't be asked to do that. I'm going to need a chiller, and everything will be moved into one tank well beforehand.

The new tank is a 40B and the sump/fuge is around 15 gallons. So, I need to plan for +/- 55 gallons.

I have no idea what temperatures to plan for. We live in a 1960's bungalow, with crummy insulation and windows, and no a/c.

The EcoPlus 1/10hp would fit in the stand beside the sump. I don't think the 1/4hp would fit very well.

What kind of temperature spike should I plan for?

[Aquattro]

On that size tank, if you even need a chiller, the smallest you can find will probably work. Depends on whether you turn your house heat on during the summer
You could even reverse your lighting period while you're gone, have lights on in the cooler hours at night. But I've used a 1/4hp on a 180, you don't need anything that big.

[Enigma]

Thank you!

Our crummy old house heats up like an oven in the summer. Murphy's Law being what it is, if we get a temp spike it'll be while my eldest is here trying to manage things for that week.

[Enigma]

I got a very fair deal on a JBJ Arctica 1/5hp chiller off of Kijiji. I love it. While it may be overkill size wise, it was such good value that I couldn't pass it up. It is very quiet and is doing a very good job at keeping my tank below 79F.