My existing shop is 38' x 40' with a 16' ceiling and I just did an addition that is 40' x 80' with a 18' ceiling, The existing shop has a 150 btu hanging forced air furnace.

I'm wanting to do a radiant tube heater in the new shop and was thinking it would be best if I put it over top of my welding table that is 22' long so it heats the table and the table can hold the heat.

My problem is that the table is on the opposite end of the building approximately 72' away.
My question is do I use one big heater or will I be better served with 2 smaller ones.

Or would I be better off not worrying about heating the tables and run one long one the length of the building.

Your input will be appreciated.