replacing your armstron ac
I just replaced my Armstrong ac on my '78 AS 31' Sov. My armstrong had A 14" opening so replacement was simplestablished although I did use a couple of 2×2' above the ceiling plenum front and back. I went with the Coleman Mach 8 model 47024A876 which is a 15,000 btu heat pump with a condenate pump. Make sure you order this model number because all Mach 8's do not come with a condensate pump. The condensate pump is necessary because you can tie it into the AS through the wall condensate drain line. All other Coleman drain the condensate unto roof which then runs down the wall causing mineral staining ruining the bueatiful AS finish. As far as an on the wall thermostate, I was advised by Coleman tech services this should only be used wit a ducted ac so I selected the ceiling control unit which works fine. Overall, I am happy with the new unit, but don't expect it to perform well in the heat of a 100 degree Texas day with no shade although tolerablet running fans. The AS is a heat seeking aluninum can don't you know. If you really want stay cool in 100+ days upgrade to 50 amp service and install a second ac unit, but make sure you stay in parks that don't charge you for electricity.