Humidity inside the home (hardwood floor, rental, house)

[kamoto]

I’ve lived in MA, AZ, CA and now MT. First time I’ve had to buy a humidifier as I keep sniffing and dealing with a dry throat. I bought a nice Honeywell unit for my bedroom, but I think I need one downstairs as well. Any tips for increasing humidity? My in house HVAC system says humidity inside is 25% which I think is too low. I have one of those new fangled whole house air circulators as well which recycles outside air inside. I didn’t pay much attention when the builder said he can’t use real wood for the floors due to humidity. The machined wood actually looks very nice.

[Parnassia]

Originally Posted by kamoto

I’ve lived in MA, AZ, CA and now MT. First time I’ve had to buy a humidifier as I keep sniffing and dealing with a dry throat. I bought a nice Honeywell unit for my bedroom, but I think I need one downstairs as well. Any tips for increasing humidity? My in house HVAC system says humidity inside is 25% which I think is too low. I have one of those new fangled whole house air circulators as well which recycles outside air inside. I didn’t pay much attention when the builder said he can’t use real wood for the floors due to humidity. The machined wood actually looks very nice.

Winter in MT is a triple whammy in terms of low humidity. Not only is the climate dry (so your recirculation system is bringing in dry outside air), but cold air has less capacity to hold moisture than warm air. It also means you're heating inside air which dries it out even more. May be less of a problem when you're not heating. If your air re-circulator has manual settings it might help a little to set it so it cycles less often during the winter. Some HVACs have ways to humidify circulating air...don't know about that as I've never had an HVAC with that feature. Live houseplants can raise the humidity (but it would take a LOT of them to raise it noticeably), and using more humidifiers. When you shower a doorway fan can help redirect moist air out into the rest of the room. If you are burning a woodstove keep an open pot full of water on top. Not quite sure what you meant by the comment from your builder. Hardwood certainly can expand and contract a bit with major changes in humidity but hard to imagine it is so severe a hardwood floor can't be laid in a MT house.

[nm9stheham]

Your builder could use wood for the floor but he does not want to, and may have had some bad experiences beyond his control. Often folks won't understand and keep the wood moisture content up in the winters in a very dry climate. Then the wood will reach a stage of dryness where, with just a slight bit more drying, it will suddenly and rapidly start to shrink, show big gaps, etc. And if over a slab or crawl space when it sees higher humidity, then the top can dry faster than underneath, and the wood will cup.

Here is one article saying that the house needs to stay within a humidity range of 35-55% to avoid drying the wood so much as to reach that stage of driness where rapid shrinkage starts... which the OP's house is not.
https://themasterscraft.com/protect-...me-humidifier/

[kamoto]

Thanks for the inputs. I’m over a crawl space so must be the issue referred to in that link. Interesting that the builder didn’t put in a whole house humidifier. The AC unit is in the attic, but the water heaters are on the first floor. That’s the other weird thing in this house. Two 50 gallon electric water heaters. For a 2500 sq foot house. Seems nuts to me. And you can’t shut one off as they work in conjunction with each other. The HVAC guy is a good Italian family business. I’ll give them a call for some options.

[kamoto]

By the way, it’s a HRV. Heat recovery ventilator. Mechanical ventilator which is needed for super energy efficient homes. Last electrical bill was 167, and there is zero condensation on any window. So I’m pretty happy except for the low humidity situation. Interesting though is they say an ERV is best for cold dry climates. Who knows, HVAC is confusing to me.

[nalabama]

We had two 50 gallon water heaters in our house too, but one of them fed a large Jacuzzi step-in bath tub. It was barely satisfactory at that. If they had been linked together it would have been more useful.

[nm9stheham]

Originally Posted by kamoto

By the way, it’s a HRV. Heat recovery ventilator. Mechanical ventilator which is needed for super energy efficient homes. Last electrical bill was 167, and there is zero condensation on any window. So I’m pretty happy except for the low humidity situation. Interesting though is they say an ERV is best for cold dry climates. Who knows, HVAC is confusing to me.

Well, the 'zero condensation' is a sign of the low humidity. You seem to need some sort of humidifier for comfort. That advice from 'them' is too generic to cover all situations; you're in a very dry climate. Let us know what you end up with.

And the dual, coupled 50 gal water heaters is to just keep the water warm in high demand situations. (We just sold a largish vacation rental house that had 3 water heaters coupled in series for high demand use.)