Yet another follow-up!

If you're making a video on heat pumps, can you please also go through the "Dry" function? I understand that a heatpump can dry by letting moisture in the air condense on colder surfaces, which happens all the time when used as an air conditioner. But what does the dry mode actually do? Does it heat as well in order to let the air hold more water?

It takes a while for new tech to settle down. I noticed when going from an open fire to central heating radiators (oil fired) that the house got very dry. I guess the Victorians noticed the change when they went from gas lighting to electricity. Sadly quite a few people didn't find out about carbon monoxide poisoning and condensation until they had fitted double glazing. One thought though, could you use the water condensate drawn from the air by your heat exchangers (Air con and Air-source heat pumps) in your humidifiers? You should get less limescale and atmospheric minerals.

Jim Hewlett

I use those little balls that you toss in your humidifier that inhibit mold growth with silver. And I filter my humidifier water first using one of those sink water purifiers. Works great.

Hodgkin LeBlanc

Similar question here: I have home AC system 3+1 unit. Some people with asthma or many pot flowers at home argue that AC dehumidify the air too much. I haven't noticed any effect on me however indeed my system dehumify air before the cooling starts. I have no read on air humidity so I don't know the actual levels before and after. So the question: Would it be totally silly idea to run AC unit and humidifier in a room? Effectivelly fighting each other in glorious energy inefficient battle? Or does some smart AC systems allow to turn off dehumidifying completely?

Radek Věchet

Thought of the day. AirCon units will reduce humidity as standard and drain the water away outside. But are there any units that will ADD humidity to the air to truly CONDITION the air to perfect levels ?

Colin Grimshaw

I've seen Stadler Form had these types of humidifiers named "air washer", as they claim it also doubles as an air purifier.

Speaks of sealed homes without air exchange, here's a new topic suggestion: HRVs and central exhaust systems. This will conclude your furnace trilogy: furnace, AC and HRV.

You didn't talk about these, no idea how they're called: https://i.imgur.com/96MQcdN.jpg It's basically the same as the evaporators except that it's using those rigid discs with a rough surface to provide evaporation area, the fan motor has a geared output that rotates them slowly into the tank, water clings to the rough discs and gets into the airstream. That's a pretty small unit and evaporates about 6L/day, and that style does away with the issues of impregnated felt getting gross or needing replacement. Had it for 3 years or so and never got gross unless I forgot it for an extended time with the little leftover pool that can't touch the discs (bottom is curved too, so it's minimal) and it's easy to clean as everything's rigid. Water is hard here but it isn't even much of a problem, scale is still rough so water still clings to the discs even if there's scale on them, and it's pretty easy to break off by flapping the discs a bit. Prior to that I bought an ultrasonic one and it was terrible, it had a built-in descaler like you mentioned but even with that, plus filling it up with water that had already gone through another descaler first the scale dust was unbearable - not only making things dirty but most importantly when you run a humidifier to avoid sore throat getting an ultrafine mist of rock powder in there in return is 10 times worse...

Kilrah

Fun fact about humidity. There are very few standards, and a surprising lack of studies regarding human habitation humidity levels, but what little is out there usually says that a "good" humidity level is ~50%. This, however, is not a result of those levels having been in some way scientifically proven to be best, but because it's simply too expensive to go any *lower* than that. That's right. All those guidelines are written from the standpoint of de-humidification, and cost analysis. Meanwhile, 50% humidity is considered the low end of the "it's dangerous to humans" zone, because of all the bacteria, legionella and mildew issues. ¯\_(ツ)_/¯

Arni Bjorgvinsson

I know the problem of moisture forming on the windows, my place (a stone house built around 1930) was renovated in a time that people thought that everything should be airtight, it's not so nice, I discussed with my landlord to drill some holes... They also did not think about small openings and stuff to let fresh air in, maybe extremely energy-efficient, but not the best way. Looking forward to your set description, I just noticed a bare CRT that I can't remember from the move to HQ?!?

MrHammond

Related anecdote: the other day my cat knocked the dryer exhaust duct off the back of the dryer while I was running a load of towels. It’s amazing how many pounds of water a dryer is capable of pumping into the air in a short time. Everything in the room was soaked. So point being, yes, too much humidity inside can be a problem.

alphawhiskey

Same here in Ireland. The one I have (Meaco 20L) can collect to 2 to 3 litres a day during wet / misty weather just to keep under 60% RH.

Seán Byrne

My fiance has a piezo style humidifier we keep in the bedroom. I just noticed last week it is causing the hardwood floor to warp. So now it sits on top of her dresser instead of the floor. We added a glass top to the dresser to keep from damaging it. And now I'm very interested in a evaporative humidifier to replace it. Thanks!

Nathan Musick

CPUs (and other processors) are space heaters and software radios that can kinda track time and barely do math. Waste heat FTW! (In my 20s I would use my gaming PC as my only heater in the winter.)

Stephen Gillie

I usually try to keep the %RH at around 50. At the moment, my house is rocking around 66%, so I'm not actually actively humidifying ATM.

Brendan Meteer

Doh! Should have given you that link to look at: https://www.ebac.com/dehumidifiers/

Colin Grimshaw

Alec. Here in the UK we have the opposite problem with, at times, humidity that's too high. In my case I was getting indications of 62-64% in various rooms. I investigated this and decided to buy a DE-humidifier. Having looked at all the potential options I got one that will look like a portable air-con unit to you! And that;s what it more or less is. Have a look at the web link and you'll see what I mean. Mine condenses moisture on the fins and it collects into a 2.5L tank. When I first got this and ran it, a full tank was collected in a full day and I was shocked as to how good it was!

Colin Grimshaw

I replaced a 9'x4' picture window from 1966 a couple years ago. Though it still had its seal, it was always the indicator when humidity was getting too high. Christmas dinner was always a good source of far too much humidity!

Michael Steeves

We had an impeller humidifier when I grew up in the 90s. The impeller is like a squirrel cage/centrifugal fan, but instead of having a large opening in the side to let air in it has a straw to pull up water. There were probably air inlet holes too, but I don't remember. Eventually the motor bearings failed and we got an ultrasonic replacement that seemed more effective. I found the exact model we had on ebay: https://www.ebay.com/itm/DeVilbiss-Vintage-Cool-Mist-1-1-2-Gal-Humidifier-Model-250-Original-Box-Manual/254832560409

John Hiesey

Yes to the background scenery explainer; we’ve had some of it in pieces as Patreons, but I don’t think everything. Ewen

Ewen McNeill

Thank you for inspiring me to get a wood stove humidifier.

Brett Walton

I use a traditional wood stove to heat the house. A simple tea kettle is used to keep the humidity in the room.

Brett Walton