Will I have to fiddle more with valving, and air supply, etc., being at 5500 ft. above sea level? Should I figure on losing 10% or more in BTU's due to altitude? When I go to various manufactors web sites and they talk about altitude in the on line manuals, they seem to end the high altitude at 4500 ft. I am 1000 ft higher than that, is this going to be a problem?