Refinancing Commercial property, what Cap rate do they use?

[Jonathan Mueller]

I am looking to start investing in larger multi family properties, I just refinanced my primary home and as part of that, they ended up paying off my duplex (to keep debt to income ratios in line) SO now I have a paid off duplex  and am looking at collateralizing the duplex to purchase an 8 plex that has a 15 cap rate. If I buy this 8 plex and then want to refinance in a year or two (to pull cash out for the next deal) what cap rate does a typical commercial lender use to determine value?