The Best Winter Humidity and How to Increase It

Is High Humidity in Winter Better?

During summer, coastal areas struggle with high humidity while arid states have an almost perfect humidity level. Things are however quite different when winter kicks in.

Relative humidity is the amount of water vapor in the air expressed as a percentage of the total amount that the air can hold at that temperature. It is therefore correct to stay that relative humidity is a function of temperature.

temperature and humidity readings

Hot air holds more water than cold air. And that is the reason why relative humidity is high during the summer than in winter. Also, you will notice that when warm and humid air is cooled, the air’s potential to hold water reduces and hence the water vapor condenses.

Low relative humidity is just as bad as high humidity. When it is too high mold grow in the house, musty odors develop, asthma and allergies worsen and you feel uncomfortable. Low humidity causes your skin and eyes to dry and itch, you suffer respiratory infections, and wood and furniture cracks.

You are likely to struggle with low humidity during winter than during the summer.

So, what is the best/ideal relative humidity in winter? And how can you increase the relative humidity in your house?

The best humidity level in winter is 30-40%. That range of humidity prevents your skin and eyes from drying, respiratory infections, static electricity, dehydration and itchy skin. It also prevents your furniture from shrinking and cracking.

20% relative humidity in winter will be low but not too low especially if the outside temperature is really low as well. Actually 20% relative humidity would be recommended if the outside temperature is between -20 and -10 degrees Fahrenheit.

55% relative humidity during winter would be considered high but ok during the summer. When outside temperature is 50 degrees Fahrenheit or higher, the maximum relative humidity in the house should be 50%.

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Understanding Relative Humidity vs Temperature

A lot of people struggle with the concept of relative humidity. As I mentioned, relative humidity refers to the amount of water vapor in the air as a percentage of the total amount that the air can hold at that temperature.

Increasing the temperature of the air increases its potential to hold more water and hence hot air has a high relative humidity. Also, lowering the temperature of the air causes its moisture-holding potential to reduce and that is why when you cool air it sheds of water in the form of condensation.

When warm air comes into contact with glass, its temperature drops hence condensation occurs

However, increasing the temperature of air does not necessarily mean that its relative humidity will automatically increase. There needs to be a source of water for the hot air to take up.

And that is exactly why the average relative humidity in Florida is 74% percent while that of Arizona is 38.5% despite Arizona being a hot and dry state. In Florida, evaporation from the sea means that the air around will be saturated with moisture.

In Arizona however, water bodies are so far away and hence the air remains dry.

Apart from that, it is important to mention that relative humidity affects how hot or cold the air feels. High relative humidity makes air feel hotter than it is and vice versa, as shown in this relative humidity chart.

For example, when the air temperature is 85 degrees in Florida and with a relative humidity of 75%, it actually feels like it is 95 degrees. However, at the same temperature (85 degrees) and relative humidity of 40% in Arizona, the temperature feels like it is 86 degrees.

Low relative humidity also makes the air feel colder than it actually is. That is why winter in Florida may not be as bad as in other arid states.

All this is to stay that relative humidity is not the same across the US and the entire globe. Some places will have moist air and some (especially arid states) will have dry air.

It is for that reason that the ideal humidity is expressed as a range. Also, just like temperature settings, people have different comfort levels.

How to Increase Humidity in Winter

As I mentioned earlier, the signs of low humidity during winter are:

  • Dry itchy skin
  • Dry eyes
  • Respiratory infections
  • Cracking wood and furniture
  • Peeling off paint and artwork
  • Dehydration
  • Nose bleeds
  • Static electricity

By increasing the relative humidity in the house, you will stop all the above from happening. The following are some of the ways to increase the relative humidity in your house.

1. Install a Humidifier

whole-house humidifier
Whole-house humidifier

A humidifier is an appliance which automatically adds water vapor into the indoor air thereby increasing the relative humidity of the house. There are portable humidifiers and whole-house humidifiers.

Portable humidifiers are stand-alone units which can be moved from one room to another and all you have to do is plug them to a power outlet. They are only used to humidify a specific area of the house.

On the other hand, a whole-house humidifier is added to your HVAC system where it humidifiers the air in the ductwork thereby increasing the relative humidity of the whole house.

Portable humidifiers are cheaper than whole-house units and don’t need any installation. They are however limited in their output.

Whole-house humidifiers are not cheap but will regulate the relative humidity in the entire house. They also cost a lot in installation since they need to be installed by a professional HVAC contractor.

If you live in any of the arid states, the air there will be quite dry during winter and you should have whole-house humidifier installed. Luckily for you, you will most likely not need a dehumidifier which folks living in humid states will need during the summer when relative humidity is too high.

2. Boil Water in a Stove

Any form of cooking adds water vapor in the air but boiling water in the stove is the easiest and quickest way of increasing the humidity in the house. The dry indoor air will readily take in the vapor coming from the boiling water.

3. Have Pots of Water in the House

Another way of naturally increasing the relative humidity in the house is by placing pots of water throughout the house. The dry and warm air from the furnace will absorb the water and improve the overall humidity in the house.

Placing a bucket of water near the furnace is also a good way of ensuring that the air being supplied in the house is moist. The hot air inside the furnace will pull up moisture from the bucket and supply it to the various living spaces in the house.

4. Shower with the Door Open

Showering produces a lot of vapor and that is why condensation happens on bathroom windows during the summer. However, you can turn that to your advantage during winter.

If possible, take a long hot shower with the bathroom door open to allow the water vapor to spread throughout the house.

5. Don’t Drain the Bathtub Immediately

After soaking in the tub, I would recommend that you let the water sit in the tub for a while instead of draining it immediately. As long as the water stays hot, it will keep on producing water vapor which will help increase the indoor relative humidity.

6. Have Some House Plants

House plants do not only improve the overall décor of the house but they can also be used to increase the relative humidity. Their leaves have small openings which open to release water vapor in the atmosphere while they take in air.

If you keep watering your house plants they will also keep on releasing moisture in your indoors which will improve the air quality in the house.

7. Dry You Laundry Indoors

Drying your laundry indoors or venting the dryer inside the house can naturally increase the humidity in the house. While it is not advisable during summer, it is perfect for winter.

Also, if you have a dehumidifier in your laundry room, do not run it during winter. It will remove moisture from the air thereby lowering the humidity when in actual sense you need to increase it.

Wrap Up

And basically that is a brief guide on the ideal relative humidity in winter as well as how to increase it. I hope you enjoyed reading this post.