Humidifiers are not generally needed here in the SF Bay Area. IMHO. The winters are generally wet, and the maritime influence keeps the summers relatively humid (albeit hot and rainless).
In my previous abode I got a humidifier and had it running the living room besides the open stairway to the second floor. All it seemed to do was encourage the growth of mold on some of the walls.
In fact, in the current home, I've taken pains to air out the attic and crawl space as much as possible... due to reading that there's a lot of moisture that enters a home through a dirt crawl space. Put plastic sheeting down over the earth floor of the crawl... added soffit ventilation to the attic... even laid sheeting down between the ceiling joists up there. Although that was probably unnecessary in retrospect. The whole goal was to avoid having moisture collect in the attic and create a mold problem. It's an unfinished attic with very limited head room, so it's not like one is losing any living space up there.
Biggest improvement was from adding fiberglass batts to the attic (it was previously non-insulated). Prior to that, the furnace would run almost continuously on winter nights. After all the insulation and sealing, it runs for just a little bit even on cold nights. I even did a statistical analysis of the gas consumption before/after insulating, adjusted to take into account the average monthly temps, and found gas consumption was cut to a third to a half of the pre-insulated consumption. And the home is much more comfortable. Of course, this being California, the utility bills still go up, since the price of gas (and electricity) seems to rise every year.
In my previous abode I got a humidifier and had it running the living room besides the open stairway to the second floor. All it seemed to do was encourage the growth of mold on some of the walls.
In fact, in the current home, I've taken pains to air out the attic and crawl space as much as possible... due to reading that there's a lot of moisture that enters a home through a dirt crawl space. Put plastic sheeting down over the earth floor of the crawl... added soffit ventilation to the attic... even laid sheeting down between the ceiling joists up there. Although that was probably unnecessary in retrospect. The whole goal was to avoid having moisture collect in the attic and create a mold problem. It's an unfinished attic with very limited head room, so it's not like one is losing any living space up there.
Biggest improvement was from adding fiberglass batts to the attic (it was previously non-insulated). Prior to that, the furnace would run almost continuously on winter nights. After all the insulation and sealing, it runs for just a little bit even on cold nights. I even did a statistical analysis of the gas consumption before/after insulating, adjusted to take into account the average monthly temps, and found gas consumption was cut to a third to a half of the pre-insulated consumption. And the home is much more comfortable. Of course, this being California, the utility bills still go up, since the price of gas (and electricity) seems to rise every year.