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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.
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Home Comfort Issues - Reasons Why

Bel Air, MD
Southampton Community
Harford County, Maryland
 

Why is it so hot or cold upstairs?

There are several articles I could write about why it is so hot or cold upstairs in your house, but this one will focus on an issue that I have seen in several communities around Maryland.  This particular community is the Southampton Community of townhomes in Bel Air, Maryland. 

The reason I particularly like this story is because it can really illustrate to the homeowner what the envelope of the house is and how the thermal boundary around the envelope is so critical to comfort and efficiency.

Building Envelope

The best way to describe the building envelope is to say that it is the separation point between the inside of the home where you live, sleep and pay for air to be conditioned and the outside which can be described in several terms.  One obvious choice is the area outside the door or window. 

The "outside" can also be the space beneath your feet if you live over a crawl space or above a garage.  The area above the ceiling on any floor that has a roof overhead would be considered the attic and the attic is considered the "outside", despite being covered.  It it still exposed to the outside temps through openings that are in place to maximize ventilation.

Learning the proper way to seal and insulate your attic, crawl space and basement and where exactly to treat can go a long way towards home comfort and energy efficiency.

How to Fix

In identifying your home's envelope, you must also understand and come to grips with any limitations you might have as a result of the construction style of your building.  Some of the areas that need treatment might not be readily accessible (behind drywall) therefore might not be worth the money to remove/re-do. 

One way to improve comfort in Bel Air homes is to go for the low hanging fruit, or the things that will cost the least to treat and get you the most return for the investment and that includes reduced usage as well as comfort.

Once you can clearly establish the envelope of your home, you are ready to understand the fundamentals of making the inside more comfortable/evenly conditioned and use less energy to do so.  This example of an incorrectly insulated attic will illustrate these fundamental concepts on how to identify some aspects of an attic and what treatment to use to improve any deficiencies.

If you need help to determine the envelope of your home, consider a BGE Home Energy Audit with Hometrust, an approved BGE contractor.

The Situation

In this case in Bel Air, Maryland the homeowner is fed up with high energy bills, particularly in the winter months.  They have been in the home for 10 years.  They had solar panels installed to help with the energy bill.  Unfortunatley, the bill is still too high and they are freezing in the winter, especially upstairs.  

The 2nd floor back bedroom wall according to the homeowner "must not have any insulation".  It is drafty and the heat pump (all electric home) cannot keep up with the demand.  A friend mentioned that they should get a BGE energy audit just to see what recommendations can be made.

When you first start as an energy auditor this scenario can be kinda scary, especially when you see the solar panels.  You always want to be able to help and if you can't find anything then you won't get the satisfaction of making a difference and the homeowner will be disappointed. 

At around audit #100, you begin to realize that, much like a doctor knows when you are truly sick, the symptoms being described are pointing to some likely serious deficiencies in the thermal boundary around the envelope of the home (insulation).

Investigation Time

We took a tour of the house after speaking about the concerns and immediately I noticed the cathedral ceiling style with the drop down 8' ceilings in the bathrooms and closets.

This photo was taken from the center of the home in the 2nd floor hallway.  The rooms on the front and rear (right & left) have sloped ceilings.  The orange vertical line and the burgundy horizontal line show how the attic drops down behind to the lower ceiling in the bathroom.

 

8" Ceilings in the bathrooms and closets on the second floor of the townhouse create kneewalls through the upstairs and attic.

On this particular November morning it was somewhat chilly and I know that it will warm up considerably over the next few hours with it being a somewhat sunny day.  So, I decided to take a few thermal images prior to seeing the attic. 

I was hoping for a few good ones from what I presumed to be the situation in the attic with regard to how the insulation was installed.  The house floor/ceiling plan was setting up for a classic mistake I see from time to time with the insulation placement.  And, I don't think that the issue was because the builder's insulation contractor was taking any short-cuts.  They took great care to do the work they did in the attic.

The thermal image was taken on a cold day so the blues/purples are the cold areas and the yellows/oranges show warm areas of the surface.

 

Through the doorway below the kneewall on the left of the photo is the master bathroom which also has an 8' ceiling.  The closet below the kneewall on the right also has an 8' ceiling.

KNEE WALL DEFINITION: A kneewall is a vertical portion of a wall that touches living space on one side and the attic or outside on the other.   

Master bathroom ceiling is 8'

Additional thermal imaging taken upstairs before visiting the attic showed a lot more missing insulation. 
Here is what the thermal (infrared) images showed.

The image above shows the hallway bathroom ceiling including a portion of the push up attic access hatch.  The stark purples are detailing a story that I think I know is about to play out and it is how the insulation in this home is incorrect and is following the incorrect boundary line.

 

More signs that the insulation looks to be working at the surface of the sloped ceiling, but at the knee wall, insulation appears to be not working.

 

As seen in the hallway bathroom 8' flat ceiling, the ceiling appears cold in the master bathroom 8' ceiling establishing another trend at the lower ceilings of the 2nd floor.  The sloped ceilings appear to be insulated, but the walls the drop down and the lower ceilings do not seem to be as "buttoned up".

Time to Take a Look in the Attic

If you have ceiling configurations that resemble what you have seen above then you should take a look to see what is going on in the attic, especially if you feel drafts and you feel like your energy bill is high.  You should look in your attic regardless and please get an energy audit done if you have not because there are important concepts that need to be understood for the money spent on insulation to pay you back in comfort and energy savings.

If things have not started to get a little clearer for you on what might be going on with the insulation in this home then the next series of photos will hopefully help you piece it all together.

Attic access hatch in the 8' hallway bathroom ceiling.

 

I'm in and I always take a photo of the access hatch for future treatment specs.

 

 

A glance up and what do we see?  Insulation suspended above our head.

Let's take a moment to pause here.  If you see insulation above your head and nothing below or around you, then there is a good chance that something is out of sync.

Here is what it looks like from above:

 

To fully understand why this is wrong, the following concept has to be grasped:

An air barrier is any material that restricts/stops the flow of air through a walls, ceilings and floors.  A thermal barrier gets in the way and slows down the transfer of heat. This can be accomplished through different insulation materials (e.g., fiberglass, rock wool, cellulose, polystyrene, polyurethane) and applications (batts, blown-in, spray foam, rigid board, and granules).

Regardless of which material and application is used, insulation is not fully effective unless it is installed properly which means to be fully aligned with a contiguous air barrier. Insulation works because it incorporates air pockets that resist the flow of heat. This resistance to heat flow is measured by the R-value of the material.  However, most insulation (with the exception of spray foam and rigid foam board) does not stop air flow.

Thus, for most practical insulation solutions to be effective, a separate air barrier or pressure boundary is needed to stop the flow of air. Aligning the air barrier with the insulation will improve insulation performance, reduce drafts and improve comfort, save energy and improve indoor air quality.

In this case, as with most homes in Maryland, there is no air barrier. The suspended insulation is not in contact with the two surfaces that is is supposed to "protect" An attic gets hot and cold. It is considered the outside of the house despite being covered. The thermal images above (taken on a cold day) show that the cold air is flowing through the suspended insulation and is interacting with the "naked" drywall. In other words, the suspended insulation is doing very little to insulate the walls and ceiling that are not insulated.

A birds eye view shows that at the flat ceiling over the hallway bathroom and the master bathroom (bottom of photo covered in some type of black sheathing with no insulation beneath).  The kneewalls are to the right and left and are not insulated and the insulation is suspended at the joists that make the sloped ceiling.

Insulation Recommendations for this Problem

First, while the attic floor (above the bathrooms and closets) are clear, it is time to perform air sealing with one part spray foam that you can purchase at your local hardware store.  Take your time on this measure.  Seal all of the cracks and crevices around penetrations where air can flow through.  Here is an example of an attic that is in the process of being air sealed prior to adding insulation.

Air can travel down into the wall cavity with no barrier in place creating drafts, inefficiencies, and high bills.

 

Around the perimeter of the area, the wall cavity should be blocked and sealed.  Any rigid insulation board can be easily cut to size and inserted to divide the cavity from the attic.  Once in place, air seal additionally with spray foam to create an air barrier.  

This is a kneewall in the process of being sheathed with skyflex, a type of insulating sheathing.

An example of a well insulated attic flat and kneewall