Humidity on window.

High Humidity After Getting a New High Efficient Furnace

Excess Humidity after putting in a high efficiency furnace is not uncommon.

Frosted window in winter with humidity on it.High efficient furnaces do create condensation internally but not humidity in the home.  As your local furnace installation Winnipeg experts, we wanted to help clear up some details on this issue. This is a common misconception because these high efficient units are also dubbed, ‘condensing furnaces’ by some, because through the process of combustion and the removing of the heat from that combustion, the exhaust is brought to the point of condensation.

This condensation is drained away from inside the heat exchanger of the system to an appropriate drain at the residence.  This moisture should never be in contact with the air that gets tempered and delivered to each of the rooms in your home.  Therefore, this condensation which is created by a high efficient furnace should never increase the humidity in your home.

If the furnace you have replaced with the new High efficient furnace was a ‘standard’ or a ‘mid efficient’ it would have had a metal chimney.  In some cases, the replaced furnace would have plastic venting, however, usually only a one pipe system.   The key thing to note is the difference in what air your furnace uses in the process of combustion.

If your furnace uses air from your home to facilitate combustion you will be able to clearly see the flames when you take off the front panel of your furnace.  In some cases, you can see a plastic ‘intake’ pipe sucking in air, from your home, into the furnace to provide air for combustion to your furnace.  If a furnace uses air from the space it is heating, that means it is also removing the properties of that air; Its humidity, its heat etc.  It is also a less efficient way to heat your home.  It’s illogical when you think about it, using air that you already paid to heat to burn to heat your home.

The reason a home would get this ‘increased humidity’ is that the humidity is no longer being removed by their furnace.  So now any humidity that you and/or your family creates, whether that be through showers, baths, cooking, baking, plants or simply just an excess number of occupants (everybody gives off humidity just being), now stays in the home.  If there are no exhaust fans in the bathrooms or range hood exhaust fan above your stove, this can prove to be a problem.  Newer windows and doors installed or a tighter construction home, which does not allow much air exchange, would assist towards this high humidity condition in the home as well.

Newton’s third Law tells us that every action has an equal and opposite reaction.  So, if air is going out of your home through this process of combustion, air will come in to replace it.  In Winnipeg, in furnace season, that usually means cold, dry air.  Air that you will have to heat as well as humidify.   Enter the heat recovery ventilator or what most know as the HRV.  This contraption will take care of

  • removing the excess humidity from your home
  • introduce a measured amount of needed fresh air into your home and,
  • extract as much of the ‘heat’ quality of the exhausted high humidity air, and use it to heat up the new fresh air it is introducing to lower heating costs.

Looking outwide on cold winter day.HRV’s are standard in new building code here in Manitoba and very necessary to anyone wanting a healthy environment within their newly renovated older homes as well.  Install costs vary on difficulty of the job and size and type of the unit you go with.  You must ensure it is installed by a professional as it is extremely important it is sized, installed, and ‘balanced!’ The method of putting the system in is so important with any HVAC equipment and that rule is definitely true when it comes to HRV’s.

If not, you will have created for yourself more problems.  Not a time to get a friend of a buddy to do it for you.  If you need to save money, you would be better off to just open a window for some dry fresh air. Or, if you want, you can also get a ‘fresh air intake’ vent added into your heating system.  It is much cheaper, less measured and most definitely less efficient, but will assist in introducing fresh air into the home.

HRV’s are not all equal.  The conductivity of the heat exchanger in your HRV is important when deciding on a model.  Metal is much better at plastic when transferring heat so I suggest knowing what the heat exchanger is made out of prior to purchasing one.  If you read the above-mentioned issues the HRV will address, you may notice it does not include adding humidity to a home.

If you find that your household does not produce enough humidity to keep up with a properly fresh air ventilated HVAC system, you may want to add a humidifier to your system.  This is easily accomplished however, is a separate component. We highly recommend a non-standing water humidifier such as a ‘flow-thru’ or a ‘steam’ humidifier.  The flow thru’s are more popular based on the fact that they are substantially cheaper than the steam humidifiers.  That being said, if you have musical instruments, hard wood floors, antique furniture in the home or any respiratory issues, keeping accurate humidity levels may be pretty important to you, and well worth the cost of a steam humidifier.

At this time, I know what a lot of you are thinking,  ‘I just got a new furnace to put an end to my heating problem, and now I have a new problem to deal with!’

It’s true, ignorance is bliss.  Having that old furnace downstairs removing excess humidity, a big eight-inch hole chimney letting ice cold winter air infiltrate your home whenever it wants older windows and doors and poor insulation providing that healthy fresh air in may have been acceptable when mom and dad were paying the bills, but the price of utilities are going up all the time and like old Newtons 3rd law says, our HVAC systems have to react by evolving into lean mean heating machines. But take heart, you are on the right path to a more comfortable, more efficient and healthier HVAC system for you and your home!

And so I got one question for you… “How’s the WEATHER in YOUR Home?”

…and that’s what the Weatherman has to say about that.

For more product information feel free to visit our site www.weather-tech.net or,

If your question hasn’t been answered here, please call us at 204-799-4926 and we’ll be happy to serve you Winnipeg!

Steve De Vries is a “Red Seal” refrigeration technician with over 20 years of experience in the HVAC industry. He has been a certified Lennox Premier technician since 2006. Steve is also a Master gas-fitter licensed by the province of Manitoba. Along with his Red Seal Provincial accreditation he also holds an electrical license. Born and raised in Winnipeg Manitoba, Steve has a very good understanding of a diverse climate and the affects it has on our construction. Well versed in duct design, fabrication, ventilation, and air quality, Steve understands all the variables to take into consideration for our region as well as the science to achieve desired comfort, which is so much more than just temperature.