Residential Comfort & Energy Efficiency

Get to the Root of the Problem

A doctor always wants to get the the source of the issue. Let's consider a lower back ache as an example. If you hurt your lower back chances are the doctor will give you a muscle relaxer for the symptoms. A good doctor will likely give you a pamphlet on core strengthening exercises to get to the root of the problem.

Specialized Contractor Needed for Damp Basements

Some issues inside the home can be confusing and confounding for many contractors. A damp basement and high humidity are hard to solve.  As a homeowner, knowing where to turn for help might be difficult to figure out. Making matter worse, getting the wrong contractor can waste time or cost extra money.

Indoor Humidity and Seasonality

The recommended indoor humidity level - year round - is between 40-60%.

To get a handle on indoor humidity, the first thing to understand is the seasonality of indoor humidity.

In the summer the air outside is hot, humid and sticky in Maryland. We run our dehumidifiers in the basement. If you have not gotten around to attaching the hose most likely you are dumping water on the regular.  This effort pulls extra moisture from the air.

In the winter everyone talks about the Polar Vortex. Aside from being very cold, the Polar Vortex is also very dry! In winter our hands are cracking, lips get chapped and we need to introduce moisture into the inside air.  In this case a humidifier is used.

So, I will be clear. High indoor humidity is more of a summer issue.

Home Energy Audit

The key to solving a high indoor humidity issue is to look at it like a doctor. We need to find the source of the humidity in the air. We need to attack the problem. Where is the humid air getting in?  Waterproofing will not completely solve the issue.  Industrial strength dehumidifers are the muscle relaxer and treat only the symptom.

Having your home evaluated by a certified Building Analyst (BA) is a great way to identify home air leakage. It is important to understand that air leakage works both ways. Not only does air leak out of a house (exfiltration) air also leaks in (infiltration).

A blower door test can uncover air leakage points around a house.

Working with a Building Analyst is a great place to start for a damp basement due to a high indoor humidity issue.

Did you know that at any given time there are around forty approved BGE contractors to do energy audits for Maryland homes?

Every once in a while I get a call from a Maryland homeowner that already had an audit performed and they want to get another quote.  It happens quite often and what I can report to you is that I am amazed at the lack of details in the audits that I get to review.

Once a homeowner gets an energy audit, their home's "scenario" is registered in the BGE database.  All approved contractors can request access to the file if the homeowner authorizes it.  So, I get to see my peers final product and I can say, I have been less than impressed.

Providing a comprehensive energy audit is a specialized service. It takes many hours of training, hands on experience and practice to give a great all around energy audit.

With so many houses in Maryland and so few BGE auditors how can you be sure to get a great auditor that hits on all points? After all, you only get the audit one time for the discounted price of $100.

Here are the questions you can ask the company (including us) you choose for your BGE energy audit:
 

1. How many BGE energy audits has the assigned auditor performed?

2. What is the auditors background before becoming an auditor?

3. What level of detail does the auditor plan to add to the energy audit report?

4. What is the physical condition of the energy auditor assigned to my house?

5. Is the auditor a good communicator and willing to engage?

Let's explore each of these questions a bit further.
 

1. How many audits have you completed?

Collecting the necessary data points during an energy audit is important. Having the repetition and experience allows a great auditor to assign time to the issues. If an auditor is new, taking accurate measurements may be a challenge. The auditor is learning on the job.

Everyone has to start somewhere, but do you want your one-time discounted audit to be the one? A great audit can unlock amazing concepts that will put you in control of comfort and energy usage.

2. What is the auditors background?

An energy audit looks at a house in a different way than a window consultation or roof estimate. An energy auditor is a three dimensional thinker whereas a window salesman has a one track mind. And, I am not even talking about making the sale.

An energy auditor needs to know a little bit about everything around a typical house. Having a background as a home contractor helps, but also being a homeowner is important. Experiencing and problem solving around your own home generates great learning experiences. These experiences along with learned concepts can go a long way towards helping you!
 

 

3. How is the final report going to look with a mediocre BGE energy auditor?

It is going to be a complete bore. The template for the BGE energy report is well designed and the information is good.

A great energy auditor will add details that pertain to discussions you had. Your BGE energy report final copy will be something you can keep for reference.

4. Should I really ask about my auditors physical condition?

Believe it or not, but doing a BGE energy audit the way it needs to is demanding work. An auditor must be able to get in small spaces, climb in attics and inspect crawl spaces. An auditor must be in good physical condition to perform a great audit.

5. Communication Pulls it All Together

An energy auditor needs to be so many unique things and on top of that if they are not personable, then it is a waste.

An energy auditor must be able to articulate key concepts in easy to understand ways. If the auditor cannot complete this task, the BGE energy audit could end up being useless.

 

Why does Mold Form on Plywood?

Typically, condensation in the attic starts due to a moisture issue created by introducing two completely different air masses.  Here are the two possible reasons this problem is happening in your attic.

1. No AIR SEALING at the attic floor to stop warm, conditioned air from escaping into the attic (warm air/ winter issue) coupled with a lack of adequate attic ventilation creating conditions that are right for condensation that adheres to the plywood and eventually forms mold.

2. In summer a leaking AC HVAC duct in an attic and other HVAC related inefficiency can allow air to seep out and interact with the hot humid attic air, particularly if the attic is not well vented.

 

If you find this helpful, check out more info on my YouTube Channel @homeairleakagetest

 

 

 

Warm Air Exfiltration - Winter Issue

Signs that you have an attic moisture issue problem during cold months can be seen on the plywood in some cases.

 

Winter Problems - What to Look out For

Frost and frozen droplets on the tips of nails and hurricane clips is a sign that warm, humid air is migrating from inside the home into the attic and settling in the wrong places.

Poor ventilation is trapping the air rather than allowing it to organically or mechanically be exhausted (through ridge vent or attic fan).

But, how is the warm, humid air getting into this attic?  The usual suspects...can lights and top plates!

Recessed light thermography taken at the attic floor reveals heat from the inside of the home escaping into the attic.

 

  
Close up of a recessed light from attic taken during winter conditions.

   
Thermal image of the recessed light taken from inside the attic.

 

Top plates are also leaky spots if not air sealed properly.  A top plate is basically the top of a wall/partition between the area below.  A top plate will exist in the hallway, between rooms and between other areas that are separated by a wall.

 

Close up of a top plate. 

Thermal image of top plate close up.

 

Summer Condensation - How it Formed in This Attic

This example is one I came across during the attic inspection at a home energy audit.

I have been in a lot of attics and seen a lot of plywood in attics (for which I am very proud!).  I was not exactly sure on this one at first. 

I have seen small patches of discoloration due to poor bath exhaust ventilation or a disconnected duct, but I have not had a mold case.  

At first when I got up in the attic I could see the stains.  It was apparent quickly that there was an issue beyond what I usually see.

At first, I considered the possible interaction of the conditioned air in the living space below and the warm humid attic air.  A large opening or bypass?  That seamed unlikely based on what I had seen up to this point.  Then I turned around.

The poor duct was lying completely undressed and quite dirty.
 

Summer Moisture - 4 Things to Lookout For

Here is the recipe for mildew and mold growth on the plywood in warmer months:

1. HVAC Ducts

*Second HVAC system located in the attic or crawl space. 
*The connected ductwork is also in the attic or crawl space. 
*The ducts are leaky and improperly insulated allowing cold air to escape.

2. HVAC System Size

*Second HVAC system improperly sized. 
*Too large for the space/square footage it is servicing. 
*The larger blower is pushing cooler air through leaky ducts and into the attic.

3. Poor thermostat location.

*The thermostat is located in an area that was reported to be a "hot spot" on the floor. 

4. Poor Ventilation

*Improper baffle placement.
*Blocked eaves (air intake).
*No ridgevent.
*Inoperable attic fan.

A baffle is supposed to act as a channel for the open soffit  intake below.

The soffit opening is covered with insulation not allowing good flow.
 

 

How to Remove Mold from Attic Plywood

Answer: Control the humidity and the mold growth disappears.

Here are the precise steps recommended to solve this issue for the long term.

1. Remove the insulation around the soffit/eave areas - full perimeter

2. Reinstall baffles at the eaves to promote the best possible organic attic ventilation. 

3. Re-position the insulation to not cover the openings.

4. Seal the duct seams and tightly insulate the supply plenum (main AC duct) to eliminate leakage (lost energy) into the attic.

 

________________

Written by Eric Gans
I have over 1000 energy audits under my belt in Maryland.  I like to take my personal experiences with each of my audit customers and try to get the things that concern them out into the world so others can make good home improvement decisions - in the right order - according to their needs.
 

Do you have something going on around the house? Maybe my YouTube Channel can help.
 
 

YouTube Channel @homeairleakagetest

 

I would like to hear your comments about this article.  Feel free to post something below...

It is surprising to learn that many BGE and Pepco customers are not aware of the rebates that are available for energy efficient projects around the home.  Maryland energy customers can unlock up to $7500.00 in rebates that can be used towards air sealing, insulation, duct insulation, windows, doors and heating and cooling systems.  The only stipulation: you must get a comprehensive home energy audit through the Home Performance with ENERGY STAR® program first to unlock these fantastic incentives!