Some Heating, Ventilation, & A/C units are not worth your time or effort, window cooling systems, for instance, are full of trouble! First of all, window cooling systems are loud, it sounds like you live in the middle of an intersection in the town when you run a window cooling system! Second, they do not cool all of your house.
Window cooling systems very can only keep 1 room in your lake house cool at a time; Central cooling systems are the way to go because you can hardly hear them & central cooling systems cool your entire house, well, anywhere that your HVAC ducts lead to that is; The next useless Heating, Ventilation, & A/C device is a portable space heater.
Portable space furnaces are old & aged. In this week’s current world of Heating, Ventilation, & A/C a person has HVAC ducts come up through the floor which are connected to the oil furnace & this is enough to keep their feet warm, but many people also use heated flooring which is connected to their main heater. In these cases a portable space heating system is not needed to keep your feet warm, which is this little oil furnace’s regular use. While 1 might argue that you can use a portable space heating system to heat a single room, I would argue that there are much better gas furnaces & furnaces in the heating & cooling contractor these days that will labor much better than an old portable space heater. While the do not like for window cooling systems & portable space furnaces is a personal opinion, I suppose that various people in the Heating, Ventilation, & A/C world hold the same opinion.