Huobi may have a 5BTC daily limit, but they set very low limits for each withdrawal like 4000 ALGO (~$800) , so you should be ready for these kind of surprises from them.
It makes no sense having the BTC withdrawal limit at 5 BTC worth $147,660 right now yet algo is just at 4,000. What I have known for some exchanges is that they peg the daily withdrawal limit to either BTC or USD/T
If you withdraw 4,000 algo, the equivalent amount in BTC will be deducted from the daily BTC withdrawal limit to leave you with the limit remaining.