How about the raw material of fabric duct?
Any cheap 9 volt should do just fine. The idea is to change the battery twice a year on the day for going on or off daylight savings. Any 9v will last 6 months. Millions of smoke alarms in use prove that. The problem you describe warrants a professional look-see at your hard-wired dual system. There is no way a functioning unit will go through batteries like you are describing.
the mold issue needs to be irradicated, and it is your landlords responsibility. Contact them and tell them of the mold problem. Find someone local and have it looked at yourself and possibly tested so you have proof for the land lord. You might also need a drs note to prove worsening symptoms.. Land lords can be pains about this kind of thing. Meanwhile I suggest trying to contain the mold with taped plastic tarp - it isnt fixative, but it may help her feel better. (the longer that is on there the more it will mold though! so this is very temporary!!!!) An air filter could help in the mean time. When my house molded after a pipe burst, I got really ill with asthma. We actually had to have a company come in tear everything out, and treat it and use a negative air filtration system for 3 days, it was quite an ordeal. I dont know that double paned windows would cause there to be no mold any more, my guess is it is due to condensation. You might have to find a way to keep the area drier :/ good luck. Hope she feels better. And you prob know this already but asthma is NOT caused by dehydration. It is an inflammatory allergic reaction to an allergen or irritant, or even exercise or cold air
