Making Our Home Efficient is Turning into a Nightmare!

So in order to be more energy efficient last year we re-insulated the entire house inside and out, dug down 6 feet and insulated the outside of the basement, installed all brand new low-e argon gas windows and just had our heating ducts re-done.  It has officially bitten us in the rear. 

The house is now too sealed for moisture to escape so we have to run a de-humidifier night and day (doesn't help conserve energy even though it is an efficient model) we also cannot have the heat lower than 70 degrees at all times (when before we would have it at 68-69 degrees during the day and 65-67 while sleeping or away).  If we do not do these things our humidity level can get up to 70% which is VERY unhealthy!  Also our windows collect the moisture and cause mold.  Even doing these things we still have 50% humidity which is still relatively high.  We talked to the window guy and he said he sees this all the time now, houses are too energy efficient and it is causing high levels of indoor air pollution as well as moisture issues like mold or bacteria.

Anyone else experienced this?  Have any suggestions or know of a solution?

It's quite simple, really: you need an air exchanger, which will bring fresh air in and get rid of that toxic air.

There's some basic information at http://www.airexchangers.info/air_exchanger_basics.html

(In case this site doesn't allow URLs, the address is: airexchangers(dot)info, then click on Air Exchanger Basics.)

Gina B.

my-green-home-project(dot)com

Ok sweet...thanks!  I just checked them out though and they are almost $1000 here and they sound like a pain in the you know what to install.  We may have to suffer a little longer as we just spent over $20000 making our home efficient and now it is killing us....how's that for a catch 22?

The other point that is worth noting is that of how moisture is flowing in and out of the structure.  In the above example, now that doors, windows, and structure are well sealed there is much less fresh air moving through the space. 

Depending on the type and of construction, moisture (water vapor) can penetrate walls and ceilings.  This is really based on how the building "envelope" was designed.  In certain regions of the country, moisture moving through the building envelope is less OR more of a problem.  In this case, it is a problem that was previously mitigated with leaky windows and/or doors (extra fresh air).  Additionally the occupants of the house can create a great deal of moisture (bathing, cooking, heat etc.) that must be ventilated at some point.   

Before the age of extra insulation and tight doors and windows, it never really mattered, however now it can have a negative effect.  There are plenty of tightly sealed and well insulated houses that still have healthy indoor air quality.  This is accomplished with proper kitchen and bathroom ventilation.  The "make up" air that is used to replace what is being ventilated can be a very simple system such as a small intake vent integral to the HVAC system, or something more complex which is described above; which also helps in heat recovery - thus increasing efficiency. 

A air exchange system isn't required, although it is the best energy efficient option out there to maintain healthy indoor air quality.  The final point to consider is that any time air is exchanged there are some efficiency losses; the goal is to balance indoor air quality with efficiency.     

I would also suggest a solar attic fan as a solution to remove moisture from your attic space during the winter, and heat during the summer. If you have a gable vent, a solar gable fan may be more appropriate. They are relatively cheap to buy and fairly easy to install. The 10 watt fan can move up to 1200 sq/ft of air (850cfms) and the 20 watt moves up to 1850 sq/ft (1200 cfms).

Brian

Tierrapath.com

That is a good point, as moisture will build up in the attic spaces during cold months.  If there is limited vapor retarders in the attic space below the insulation, water vapor will penetrate the ceiling, thus entering the home. 

The attic fans Brian is referencing have automatic humidity controls, so they can be set to ventilate whenever the air reaches the maximum preferred level (say 50% relative humidity) or anywhere in between.  

An ERV is the answer. In the mean time a four inch drier hose with bug screen on the outside and starting collar on the return air duct of your furnace.

Attic fans have been out of vogue for some time now.

Thanks for all your postings.  We have had someone come in and test the air.  We were able to get the humidity level down below 50% and the condensation on the windows seems to be going down.  The inspector suspects that it is because the weather here has been consistently below -40 C for over a week so the indoor air temperature cannot compete with the outside temperature of the windows.  Hopefully it will resolve now as we have done everything minor we can do (proper ventillation of bathroom/kitchen) dehumidifier etc.  If not all they can recommend is installing a home ventilation system with heat recovery and automatic humidity control.  Let's hope we don't have to go there!

If all goes according to plan, my own home is going to be tight enough to require ventilation, but I've decided to wait out a whole yearly cycle and observe what happens.

It's possible that the kitchen and bathroom fans will be sufficient, but if they are, it means air is leaking in from the outside, and that means -40 air when it's -40 outside!

There are other ways of introducing fresh air. One of them involves burying a long pipe under the frostline, where the temperature is always 10 degrees. I'll be putting the info on my website shortly.

Good luck!

Gina

OOPS! That was 10 degrees CELSIUS, by the way, or 50 degrees Fahrenheit.

Gina