Electrical – the difference between an AFCI and a whole house surge protector

AFCI's detect patterns of current that usually indicate some sort of electrical problem. Unlike a GFCI which is making sure that current going out = current coming back, AFCI's try to look for electrical usage that would not trip a GFCI but might be something causing an electrical fire. Most code now requires them for bedroom circuits.

The one major drawback for them is that some stuff tricks them into tripping. Often times larger machines with motors, like a vacuum cleaner or power tool can trip them. They are still a good thing to have, just be aware of this limitation

It partially depends on your competency with electrical work, and what kind of surge protector you get. There are two basic models I know about:

• Square-D makes a module that mounts the same way as a standard QO breaker in the panel: http://surgelogic.com/residential/surgebreaker-secondary-surge-arresters/. It is very easy to hook up, you plug it in just like a breaker, and simply run the one line to ground. (This is a "Type 2" device). There are other companies that make these as well, be sure to get one that can fit in your panel (each company does it differently).
• There are also several types of external boxes which go beside the main panel, and hook up to a 220V circuit. These are possibly a bit harder to install (you need to run conduit typically), but may offer better protection and sometimes also have surge protection for phone lines and cable. These come in both Type 1 and Type 2.

If you're comfortable opening the panel and installing a new breaker, then really either of these methods is okay, though the first is definitely easier.

The "type" I referenced above boils down to (and this is new to me, correct me if I get it wrong):

• Type 1 are designed for direct lightning strikes, though you may need a lighting protection system (rod) to take advantage of it.
• Type 2 are designed for indirect lightning strikes.

Note, having this doesn't mean you don't need surge protection on individual devices. It certainly takes a way a lot of the risk, but it doesn't eliminate it. For expensive items or things that are very sensitive (eg, computer, home entertainment system) it's worthwhile to put a powerbar-style surge protector right at the equipment).