Humidity and Filament

Is there a range of relative humidity that is ok for storing filament so that it won't absorb enough moisture to be a problem? My printer is in an unconditioned garage workshop. I have the spools stored in a tub along with a dehumidifier rod which is supposed to work by raising the temperature in a cabinet. When the garage is 55F, it can get the inside of a rubbermaid tub up to about 65F and 44% humidity. I'm not sure that's good enough. I also have a silica sachet in there which is supposed to be big enough to handle that size tub, but I understand it needs a few weeks to dry out that much space, and I don't know how much dry air would get lost every time I open it.

The simplest solution would be to keep the spools in the house which runs around 35%, but I would like to keep everything together.

Also if I have a spool out for something like a 5 hour print in 55% humidity, would that be long enough for moisture absorption to be a problem? I know I could try pulling off only as much as I will use, but I don't have an easy way of measuring the length of filament off of a spool.

PLA is more affected by humidity than ABS. You will know you have a problem if the nozzle can be seen/heard spitting (usually puffs of steam). Heat by itself will not dry out the filament if the ambient humidity is high. If it is convenient, keep the filament in a large ziplock bag, and use a vacuum to draw out most of the air (after you have dried it, that is).

You could also try putting it in a sealed container with rice.

I don't really have a problem with my PLA as I seldom have it hanging around long enough, I buy it print with it and on sell the results. Although it is kept in the workshop behind my garage under the house which also contains a freezer and a file server so it is always warm in that room even in winter

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Experimenting in 3D in New Zealand