Replacing a relay with an SSR
Looking at the datasheet shows this relay to be very small for its load capacity.

When the coil is energized the relay dissipates about 400 mW. There would be very little additional dissipation across the switch contacts, perhaps only another 300-400 mW

An equivalent SSR will drop about 1.5-1.8 V when turned on, this would mean about 16-20 Watts dissipation within the device at 16 A.
You need to assess the physical space you have and how much room you have for a heatsink. If the unit is closed (ie no air flow) then this type of conversion may not be possible at all.   

Crydom do make some small form factor SSRs like this, but it shows you the difficulty you are going to have in fitting and cooling them.

 

You could select much higher rated SSRs (20-30 A), and physically larger devices but doing so does NOT reduce the power dissipation in the SSR itself.