Forgive me if this is obvious: A HELOC is a line of credit against which you can withdraw and repay money anytime for up to 10 or more years. A home equity loan, by contrast, is extended in full, once, (eg. you receive the full loan amount in cash, to do with what you will), then repaid on a fixed schedule.
HELOC rates float, but (in my understanding) home equity loan rates are typically fixed.
Given our historically low rates, I suggest your friend consider taking a home equity loan instead of using a HELOC. (Though that depends significantly on when your friend needs how much cash, and when they'll pay it back - if they need cash occasionally, and will pay it back occasionally, then a HELOC may be worthwhile, despite what might be higher interest rates).
One more idea: Consider a personal (unsecured) line of credit - it sounds like your friend may have the net worth / income to qualify for a decent-sized personal line of credit. Try Andrey Movsesyan at BBVA Compass (tell him I sent you, please)