Do Electric Heaters DRY AIR?!

Ventless gas heaters place an additional dose of water vapor into the space as a result of water vapor being a direct byproduct of natural gas combustion. I agree with the rest of the assessments you made in the video. (I am an HVAC contractor)

Dave Bradshaw

🔥🔥🔥

Ronnie5545

Fossil fuels like natural gas release as well as wood water vapor so a gas fire may add some water vapor although most of it should be going out the chimney. I think this is more about perceptions-the electric heater neither adds nor takes water away and also does not require an air draft (which tends to suck moist air from outside in) so relative humidity will drop as air is heated.

Alistair Salisbury

Here is a speculation: So maybe the misconception is not about electric heat drying the air more than other than types of heat, but that other types of heat moisturize the air more. When we burn things, we release water into the atmosphere. Some CH chain + O2 -> Fire -> CO2 + H20 + some nasty pollutants like CO and soot. This is a red herring for most modern houses using furnaces as the burn chamber is pretty isolated from the house and all the gases are vented to the outside so we don't die in our sleep so probably not much water if any from them. But a fireplace with its somewhat inefficient venting system may release some H20 into our home, both from the combustion reaction and from water trapped in the wood. The fact we can smell smoke in the room seems to indicate at least some water is probably escaping as well. Then again, the chimney might be creating such a draft that it is sucking more moisture from the air than it is producing, especially when the fire is really going. And you can throw in the fact that old timers with wood/coal stoves often put a pan of water on their stove, so they had a primitive humidifier.

That's an excellent move. Last I checked, because I don't have natural gas, and because of the wattage my electrical is rated for, just-in-time heating is not sensible for my home as it is. That makes me sad. I might get a reevaluation, or upgrade my power hookup, or buy a new house, because hot water on demand, and not countering my AC in the summer sounds like a pretty great situation.

Paul Grodt

This is much more important for baking with natural gas. The combustion is direct, so the heat is moist, and it changes how you bake. You properly suppose natural gas heat, because it must be indirect, sends all of the generated water-vapor right up the chimney. The indirect heated air still needs a humidifier for proper comfort.

Paul Grodt

HOLD UP. High efficiency wood-burning heaters are pretty darned high-efficiency. It's just critical that they are properly designed with things like quality heat-exchangers, sources of outside air as an oxygen source, and a catalytic converter to fully combust the components. I urge you to do your research on this. But yeah, if you want to dry air, you should cool it to condense the humidity into water. We've known this since the invention of air-conditioning for paper mills. Lowering the temperature was a side effect to the original goal. I'm glad I was raised by my engineer dad. I would constantly ask him energy questions, and he would force me to mold my thinking into an understanding of thermodynamics.

Paul Grodt

ooh yeah, I also have heard it many times before... widely spread misconception

Mladen Trišić

I haven't been told about electricity drying myself. But what frosts me is when people actually believe the mendacious ads by heater manufacturers that their product is "more efficient". You'll see this all the time. I have to sadden them by letting them know that all electric heaters are the same efficiency - 100%. They may distribute the heat differently (radiation versus convection) but there is only one possible efficiency - conversion of incoming energy into room heat.

Back when portable flueless gas heaters were widely used here, the main drawback people mentioned about these heaters was that they dried the air. Unsurprisingly, most placed a bowl of water on top while in use.. Ironically, flueless gas heaters humidify the air as water vapour is a by-product of burning butane (or propane) gas, besides carbon dioxide. If you have a gas cooker, an easy way to demonstrate this is to place a large pot filled with cold water and ice cubes on a high flame hob and water droplets will form around the bottom of the pot.

Seán Byrne

Thank you for discussing relative humidity in the video. I used to work in the hard disk drive industry in Colorado. We ran into an issue that threw us for a loop for awhile one very cold January. When the temperature drops below zero F, all the moisture in the air precipitates out, and the result is outside air that’s absurdly cold and very dry. Inside the lab, we were testing drives in a chamber that was running at about 50C. The “electrically heated air” ended up being ultra-dry, if you will and this effected the flow properties of the very thin layer of lubricant on the disk drive media. The result was that the drives would crash heads if they idled on one track too long. The solution was to add a random track seek routine into the idle loop, so staying one one track too long could be avoided. NOTE: To reiterate, the problem with the hot dry air was a relative humidity problem, not a moisture removal problem.

Oh, fun - I get to be the first person to point out that human comfort has little to do with relative humidity and much more to do with dew point! The relative humidity outdoors at my location yesterday evening was 94%, but it didn't feel humid because the temperature was 34°F, and the dew point was probably about 34. Most people won't start feeling like it's too humid until the dew point is around 60°F, minimum. https://en.wikipedia.org/wiki/Dew_point#Relationship_to_human_comfort

Circuitmike

double negative?!! :D eh... I need to improve my english!!!

ElectroBOOM [Mehdi Sadaghdar]

Wouldn't a natural gas furnace technically form H2O when it burns? I'm sure most if not all of that goes up the chimney, but there's an argument for why the humidity could be lower for electric heaters. 😉

Re: lying to kids Me: if you don’t eat, you will feel grumpy and you won’t grow big and strong. 5-year old: Me: if you don’t eat, bears will come in to find your food 5-year old: Me: if you break your Nintendo, you can’t play it anymore 5yo: you a meenie daddy Me: if you break your Nintendo, it will hurt the game characters 5yo: ok. Sorry I always try the truth first. But then… I try things that work. 😬

Brian Boccia

We replaced our hot water heater with a just-in-time heater, we got one that was twice as big as we needed so we could also replace our furnace with a heat exchanger. The installer claimed it would provide a "softer heat"... It works really well, and the system has cut our heating bill in half. But, I don't really know what "softer heat" is.

you have to figure out where the humidity is coming from it can be a crawl or basement that is allowing moister from the earth in

My house 70-75 gets too humid and breathing is so difficult I keep my apartment at 62-65 and the air is super clean feeling to me and I can breathe. But I am cold. So I wear a jacket or use little baby heater.

"False misconception"?

Bruce Davis

steam boilers are one of the very few heaters that can add humidity but even they only do so if the vents are going bad

a lot of HVAC contractors do not understand relative humidity

In my area we still have some buildings with steam boilers. Those type of radiators typically disperse / off-vent steam at each location. That would be a good way to add moisture more relative humidity if desired.