Healthy Log Home: Controlling humidity

Take the humidity test:
  • Do you wake up parched, dry nose or itchy eyes?
  • Are the hardwood floors in your new log home creaking like an old ship?
  • Does static electricity make loved ones and pets cringe at the touch?
If your answer is “YES” to any or all of the above you and your home could be suffering from lack of moisture in the air.  The measurement is called “Relative Humidity” which is defined as the ratio of the water vapor density (mass per unit volume) to the saturation water vapor density, usually expressed in percent.  

Too much can encourage mold growth, dust mites and place condensation on cold windows. And too little can create potential respiratory problems, damage to the home (remember you log home is made mostly of wood!) and furniture, plus the annoying items listed above.  Both extremes can be potentially bad for humans and your log homes performance.  I bet you didn't know that dry air can also be expensive…by adding water vapor to your home you can also reduce your heating bills.  Increasing the relative humidity by 10% is roughly the equivalent of raising the room temperature by one degree.   

Years ago folks would boil a kettle of water on the wood stove, which was not very effective.  Today’s log home is typically much larger and using the kettle method is just totally inadequate.   The Environmental Protection Agency recommends keeping indoor relative humidity between 35 to 50 percent.  The good news is there are several options to create and maintain the appropriate relative humidity in your log home. 

Here are some suggested guidelines to help you decide what’s best for you:

Increasing humidity: 

Portable humidifiers:  Simple to operate, easy to install, counter top size or free standing.  Prices range from $25-$150.  The main disadvantages are the small area they cover (you may have to purchase more than one), they can be noisy and a hassle to refill with water.  Select an evaporative unit, one that creates water droplets can emit bacteria or aid in mold growth.  Make sure you check the humidifier output to insure its sized right for your home.

Whole house systems:  By far the best way to go is to have it installed by your HVAC contractor at the time of construction (you can also add it later).    Costs can range from $400-$1000.  The main advantage is they connect to your central water supply and you can control the level or percent of humidity.  They still require maintenance and should be checked periodically like other appliances in your home. 

Reducing humidity: 

Portable dehumidifiers:  Inexpensive and simple to operate, but noisy, only affect a small area and a hassle to empty the water.  Prices range from $100 to $400.  A portable dehumidifier is best used in conjunction with your air conditioning system.

Air conditioning:  Many folks think that by installing a whole house air conditioning system will control the level of humidity in the home.  By lowering the actual air temperature in your home can actually increase relative humidity and reduces the temperature of the materials in the structure which increases the risk for condensation.  If you attempt to control humidity by reducing the temperature you’ll accomplish only having a very cold living space, jack-up your energy costs and put excessive wear on your cooling system. 

Whole house dehumidifier system:  These systems are designed to remove moisture from your home.  Depending where you live, this may be a sound choice.  A whole house dehumidifier senses the level of humidity in your home and maintains that ideal level.  Better systems work in conjunction with your air conditioning system.  Check with your HVAC contractor for prices.  By maintaining the right level of humidity in your home using these systems you’ll be able to increase the temperature without sacrificing comfort, ease the wear on your cooling system and save energy costs       

Which ever systems you choose, always consult a HVAC professional for advice and costs. 
Think of controlling humidity as an investment in your home and your health.

By The Leelanau Log Home Company LLC 

Copyright 2011 Under the Influence of Wood Blog