Storage space for strings and integers

We are planning an application which will save 200 to 300 sensor data every second over 10 years and more. These raw data must remain unchanged (no data reduction through thinning etc.) Over time, the database becomes huge.
A frontend program receives all data as numbers in the form of a string, convert it and store it in InfluxDB.

  • One solution is to convert the data into float or integer and save it in InfluxDB.

  • 80 percent of the data are small integers. Therefore, another solution is to leave small integers (e.g. in the range 0-9999) as a string and save it in InfluxDB. .

In theory, a short string takes fewer bytes than an integer. Since strings have different lengths, maybe a string needs more storage space than an integer (for pointer etc.)

Some information about the storage space requirements of InfluxDB for storing strings and integers would be very helpful to finalize our concept.
Many Thanks

Is it so hard do hint what is better a int value or a string with 4 characters ?
Or is the writing not understandable ?