Humidity & Ventilation in Tiny Houses: 18 Great Tips That Works

In Tiny Houses (on wheels)by Christopher Schopf

Many people do not realize that tiny homes have ventilation requirements that other homeowners don’t worry about.  These homes can get humid very quickly which can cause moisture buildup that can lead to all sorts of problems.

A lack of proper ventilation can cause problems for tiny homes:

  • Mold and mildew to build up.
  • A wet interior.
  • Electronics to be destroyed.
  • Health issues.

Why Is Humidity & Ventilation So Vital In Tiny Houses?

The interior of an improperly vented tiny home will get wet quick.  Water will first buildup on the windows, walls, and ceilings, and will end up dripping onto everything else.  Left unchecked, this water will cause mold and mildew to build up inside the tiny home.

Electronic devices can eventually be destroyed and they can even become dangerous.  Imagine turning on a portable heater that is filled with water.

Health issues can also become a problem in improperly vented tiny homes.  Humidity levels above 70% can lead to increased sweating, increased respiration, and altered blood circulation.

This can make you light headed and can even cause heat exhaustion or heat stroke.

High humidity levels can increase the chances that you get a virus as well.  Allergens become more dangerous in humid environments and people with asthma are more likely to have an asthma attack.

There are a few reasons why a tiny home can become more humid than it should be.

The one we’ll talk about first is improper ventilation.

Improper ventilation is the leading cause of excess humidity in a tiny home and in the next section, we’ll tell you how to deal with this problem.

1.  Create an Environment with Proper Ventilation

The first step to getting rid of humidity is to not fall victim to it in the first place.  This can be done by creating a tiny house that is designed in a way that prevents humidity from forming.

The windows, air vents, and even the construction of a tiny house can all lead to more or less humidity within the tiny home. 

If you’re in the process of building or buying a tiny home, you can use these tips to help keep your tiny home from ever becoming humid.

If you’ve already built your tiny home, think about making some modifications to it so that you can naturally reduce the amount of moisture that enters your home.

2.  Use Weather Barriers

A weather barrier goes overtop of the exterior sheathing and underneath the exterior siding.  Have you ever seen a house wrapped in paper with the words Tyvek on it?

If you have, you’ve seen a weather barrier.

These barriers help to prevent water from getting into the house while simultaneously allowing water inside to escape from the house.  In addition to moisture reduction, weather barriers also help slow the flow of air so they’ll actually add a bit of insulation to your build as well.

When applying a water barrier, be sure to overlap each sheet.  This ensures that there aren’t any gaps and increases the effectiveness of the weather barrier.

3.  Use Vapor Barriers

Vapor barriers are usually just plastic sheets that are applied to the interior wall of the tiny house.  It should be placed in between the insulation and the interior wall of the tiny home.

This plastic sheeting works to stop moisture from getting into the insulation.

If the insulation does get wet, it will dry out towards the outside through the weather barrier.

A vapor barrier is an interesting tool for controlling moisture because it can decrease moisture in certain climates and increase it in others.  For this reason, it is important to think about when you’ll be using your tiny home as well as where you’ll be using it before deciding on whether or not to install one.

Vapor barriers should be used in cold climates when heat is often being used inside of the tiny house.  In hot and humid climates it should not be used as it can actually cause more moisture to accumulate inside the tiny home.

If you’re living in a place with hot and humid summers and cold winters, your best bet is to put a vapor barrier in.  This rule also applies to areas where it is hot but not humid.  In fact, the only time you won’t use a vapor barrier is if you’re living somewhere that is always hot and humid.

4.  Install and Use Your Windows

Condensation can form on windows but it can also be reduced by opening windows.  In this case, I’d say more is usually better.  The more windows you have, the more opportunities you have for venting the air in your tiny home.

Kitchen windows, bathroom windows, and even bedroom windows can all help to vent the condensation that typically builds up in these areas.

Double-pane windows will have less condensation form on them so try to stick with double-pane windows whenever possible.  If this isn’t possible, you can add plastic sheeting on the inside of the window to create an additional barrier.

This will help to reduce condensation and will act as a barrier that helps to insulate your home.

It can be difficult to place windows in tiny homes as it does reduce the amount of wall storage you can put into the tiny home.  One way many people get around this is to put their windows up high.

Clerestory windows can be placed in areas that you wouldn’t normally store heavy items so they won’t hurt your storage quite as much.  These windows are great because they provide additional light, beauty, and ventilation.

5.  Use Air Vents

Ventilation is a crucial key to reducing moisture.  RV manufacturers know this but unfortunately, many tiny home builders overlook this.

You’ll notice that RVs tend to have ceiling vents in the bathroom, the kitchen, the living area, and the bedroom.

This large number of vents helps to keep airflow moving throughout the home and can help to cool the tiny home in the winter.  All of the vents do not have to be open at once but at least one of them should always be in use.

If you’re in the bathroom, run the bathroom fan.  If you’re cooking, turn on the kitchen fan.  Just by doing this, you’ll dramatically reduce the amount of moisture that you create through daily living.

Also, be sure to have air vents that run on 12-volt DC power.  This way, you’ll be able to keep the fans running even when you’re off the grid.

6.  Use the Right Air Conditioning Systems

An air conditioning system that is too large will actually end up creating excess moisture.  Swamp coolers will also create moisture.

On the other hand, a properly sized AC system will draw moisture out of the air so it is good to have an air conditioner running on hot and humid summer days.

Some tiny homes are large enough to warrant large window units or mini-splits but many are not.  If you have a small tiny home, you may have to go with a small RV AC ceiling unit.  This type of air conditioner will be the appropriate size for your small tiny home.

7.  Use The Right Heaters

Some propane heaters will add moisture to the air.  An example of this is the Mr. Buddy ventless propane heater.  If you run this type of heater in the winter, you’ll need to open a window.  Even so, you’ll end up with more moisture than you would have if you would have used a different type of heater.

Electric heaters, on the other hand, work to dry the air out.  Electric heaters are great for reducing moisture and can sometimes do too good of a job at it.  This is why many homeowners end up having to run humidifiers in the winter.

If you’re finding your tiny home is too humid in the winter, it might be a good idea to buy a portable electric heater.

You can always continue to use your built-in system while supplementing with the electric one to reduce moisture and add additional heat.

Tip
Here’s a GREAT guide with recommendations for how to heat up your tiny house.

8.  Use Dehumidifiers

A standard dehumidifier will work to suck moisture out of the air.  These work very well but they can take up quite a bit of space.  Also, they require power to run so you’ll want to be hooked up to a power source when running a dehumidifier.

One other problem that many people don’t talk about with dehumidifiers is that they put off a lot of heat.

This might be fine in the winter but it is inconvenient in the summer months.

Tip
Here’s an extensive guide as well with our recommendations for dehumidifiers for tiny houses.

9.  Be Careful When Cooking

When you boil water or brew coffee inside of your tiny home, you create a lot of moisture.

If possible, cook outside so you don’t have to worry about this issue.

Many tiny homes have great outdoor kitchens but even if you don’t you can easily bring a grill outside to boil water on.

When you can’t cook outside, make sure you have your vent on in the kitchen.  For those of you without vents, open up as many windows as possible.  This will help the humid air escape from your tiny house quicker.

10.  Be Mindful When Showering

In an ideal world, you’d be able to shower outside of your tiny home on a regular basis.

However, this isn’t always possible and sometimes you just want to shower inside the comfort of your own home.

When you do shower, however, make sure you turn on the vent inside your bathroom.  If you don’t have a vent, open the window up as much as possible.  This will help let out steam before it gets a chance to infiltrate the rest of your home.

Also, consider taking shorter showers.  Shorter showers create less steam which in turn reduces the chances that you’ll let moisture into the rest of your tiny home.

If you’re really worried about humidity, you could also consider taking cold showers.  cold showers do not create as much steam and thus do not let as much moisture out into the air.

One last tip for showering is it make sure the shower area is completely blocked off.  A shower curtain will stop water from spilling out but it will not stop steam.

Try installing a full glass door in the bathroom so that you can completely block the steam from escaping.  With the room blocked off and the fan turned on, you’ll release a lot less steam into the rest of the house.

11.  Keep Your Vents Clean

Clean vents will work better than dirty ones.  These vents should be cleaned every six months for maximum efficiency.

An easy way to clean the vents is to use a vacuum on them.

A shop vac usually works best as you get more suction power from one than you would a standard residential vacuum.

Cleaning your vents will also help them to last longer and will result in you having a cleaner tiny house.  You basically get three benefits all in one when you clean your vents.

12.  Keep Your Gutters Clean

If you have gutters on your tiny home, make sure to keep them clean.  Dirty gutters can cause windows to leak which will certainly cause the humidity levels to rise.

Not only this but a leaking window can cause a lot of damage in a very short period of time.

For those of you who don’t have gutters, make sure your roof design is not letting water into your home.  The quickest way to create a humid environment is to send a bunch of rainwater into your tiny house.

13.  Hang Wet Clothes Outside

When your clothes air dry inside your tiny home, the water is actually released into the air.

Remove these items and put them outside to dry so that this air will be released outside.

If it is raining outside, consider putting off doing laundry or consider getting a tent and a clothesline tree to put underneath it.  This way your clothes will be able to dry underneath the tent instead of inside your home.

14.  Use Fans Regularly

In addition to your ventilation fans, you might want to consider installing ceiling fans or placing oscillating fans inside of your home.

These fans will help to increase the air flow in your home and will quickly dry out any wet items inside of them.

For those of you with really small tiny homes, think about getting table top fans or tent fans.  These fans don’t take up much space and you can run them on batteries so you won’t even have to worry about being hooked up to the grid when you run them.

15.  Don’t Install a Dishwasher or Laundry Appliances

Dishwashers and laundry appliances are extremely convenient but they create an awful lot of humidity.  They also take up valuable space and add a lot of weight to a tiny home.

On top of all of this, these appliances are costly and they dramatically increase your tiny home’s energy needs. 

Consider getting manual washing machines that you can use outside and hang your laundry out to dry outside as well.  Do dishes by hand and use all the extra space you have to store other items that don’t add to your humidity levels.

16.  Check Your Plumbing

Sometimes a tiny house becomes humid because of a plumbing leak.  Small plumbing leaks can be hard to notice sometimes but they can cause a lot of damage in a very short period of time.

If you’ve been noticing that your tiny home is more humid than usual, do a thorough check of your plumbing as well as your water tanks.  Fix any leaks as soon as you find them and don’t use the plumbing again until you do.

17.  Use DampRid

DampRid is a moisture absorber that many homeowners place in their basements and in other areas that tend to get humid.  I’ve used this in basement apartments and even in a car that had a trunk that leaked.

These moisture absorbers work quickly but you will have to periodically replace them.

Luckily, these absorbers don’t cost much and you can pick them up in most big box stores for less than $10.00.

18.  Monitor the Humidity Levels

You won’t know how humid your tiny home is until you start monitoring the humidity levels.  The best way to do this is with a hydrometer.

Hydrometers come in many forms and you can spend hundreds of dollars on a fancy hydrometer or just a few dollars for a plastic one. 

I love the way the fancy hydrometers look but in the end, I bought a small plastic one from Wal-mart for just two dollars.

It is accurate, lightweight, and doesn’t take up much space.  One day, when I see something nice that fits on the wall I’ll probably get it but for now, this works just as well.

In Closing

Managing humidity levels in a tiny home can be challenging at times but it is worth it.  Follow the tips in this article and you’ll have a much safer and healthier tiny home.