Unfortunately they will dry out the air & that prob is not helping. The only thing I could suggest is perhaps getting another oil heater to keep the house warm if you cant use that one. And I wouldn't leave the evap on at night time whilst sleeping (not sure if you do). Sorry that's prob not been much help. Keep up with the vapouriser they are great. FWIW we have a massive queenslander with gaps etc everywhere & we are using a oil heater due to our main heater not working & it's keeping us warm just fine.