Today’s Power Trip – Cats in Attic Destroy Insulation

I have been looking forward to this home audit every since I put it on my schedule. You see, this house and I have a history. This will be the third go round with this house and so far I am batting 500. The first visited was to replace the rather large back deck and get it replaced before one of the kids fell threw the rotten boards. I figure the deck was a win.

The second go round was the first home audit that left me scratching my head wondering how the heating duct system could leak so bad without being able to find where all the air was going. I figure that was a defeat. Now, here I am heading out for the third go round. I feel like an old Mohammad Ali fight. I have tried to stack the deck in my favor.

I don’t like losing. On this trip, I have invited another Energy Spy Detective named Jay and I have an apprentice Energy Spy Detective named Nathan joining me on the hunt.

The day is beautiful and inspiring. Unusual to see the sky so blue and feel the weather so warm where the surf meets the sand. The highlight of the day will be lunch time when I plan to celebrate a home energy victory with a real, award winning bowl of clam chowder and some fresh buttered garlic bread. It will be worth the wait. Jay, Nathan, and I discuss the up coming challenge during the hour ride. We set forth a plan of attack and get our sleeves rolled up. I am not sure what Nathan is thinking, but he does mention food every once in a while.

The homeowner called me a few days after she had a visit from a gentleman from the power company. Like most of us, she had some concerns about the high electric bills. The power company guy did a duct blaster test and found that the ducts leaked so bad that he would not be able to provide any hands-on work to help out. The company auditor felt that all the duct leakage was to the inside of the house and, therefore, not really a concern.

The news that a power company auditor had evaluated the home and left with his hands in the air had sparked my competitive nature. Yes, it’s true, in the world of heating duct pressure testing, ducts are evaluated on their measured air leakage both to the outside of the house and to the inside of the house. If the ducts are leaking to the inside of the house, oh well, that is where you want the air anyway. If the ducts are leaking to the outside of the house, oh my goodness, now we are trying to heat or cool the great outdoors and that is very of hard on the pocketbook.

On arriving at the house, the first thing I did was ask to see the offending electric bill. I wanted to see what the total monthly killowatt hour usage was along with the daily average and I wanted to compare the current monthly usage with the usage a year earlier. The next thing I heard is something I simply do not understand.

The owner said,”I don’t have a bill, I throw them all away.” Ouch! Folks, we need to make friends with our power bills and learn how to gather valuable, energy saving information from them. Read them like a good book. Instead of throwing them away, keep the old friends around a few years. Better yet, get the bills electronically and let the computer save them for you.

The three Energy Spy amigos take a quick tour of the home. It is a two story home with the front entrance halfway between the upstairs and the downstairs. Step in the front door and you have your choice – take the stairs down to the lower level - two bedrooms, bath, office and laundry. Take the stairs up to the main floor - two bedrooms, bath, kitchen, and living room. The home has a two car garage on the lower level. The office and one bedroom have been added by stealing room from the garage. The electric furnace is in a closet in the downstairs office. There is a return air register in the upstairs hallway ceiling and there is a smaller one at the bottom of the stairs in the downstairs hallway ceiling.

One thing that is unusual about the heating ducts in this home, along with the toys and cheerios, there are damper valves in the round metal heating ducts just inside the upstairs floor registers. Usually I only see damper valves in a commercial system. During my second and unsuccessful visit, one thing I did was open the damper valves by placing my hand down the heating ducts. The homeowner did not know the dampers were there. Opening the damper valve on one of the living room ducts increased the air flow from 625 cfm to 1200 cfm. ( I have a box with a flow meter attached, one of my energy spy gadgets)

Access to the attic is in the master bedroom closet. Nathan unloads the equipment and starts setting up the blower door. Jay grabs a screw driver and works his way into the furnace inclosure and I set up a ladder below the attic access. With the ladder in place, I invite Jay and Nathan to join me in the attic, I have a surprise for them that involves the attic insulation. Boy does that sound exciting or what! In this attic you will find the best case of trailblazing and fort construction that I have ever seen.

The insulation is packed down in a system of little trails that look like the march of the penguins took place right here. Noticeable larger round depressions appear to be resting or sleeping areas. I can remember going snow skiing and traveling a road that had 6 feet of snow stacked on both sides of the roadway. I felt like I was traveling through a tunnel without a roof. Thats what the attic insulation looked like. Little tunnel roadways without a roof.

Investigation on the outside of the house, under the eves, reveals an area over the deck, next to a  deck post, that has missing bird blocks. The family cat ( or cats ) had no problem climbing the post and entering the attic space. Let the trailblazing begin. We will see, later on, how this attic even provided a warm place for fort construction.

Nathan fires up the blower door and the monometer indicates an air infiltration measure of 2,800 cubic feet per minute. This is way too much. I would like to see a reading between 1000 and 1,400 cfm. Remember, too much air infiltration and we are heating or cooling the great outdoors. Too little air infiltration and the house might feel stale or muggy.

We walk around the house while the blower door fan is on and look and feel for areas where air is entering the house. Back door and garage door need new weatherstripping – storage area under the stairs needs sealing off – attic access lid needs weatherstripping, etc. What is of particular interest to me is the amount of cool air coming down on my bald head from the return air register in the hallway ceiling. This is a very good indication that the duct system has a leak to the outside of the home. I think the Energy Spy Pros are on to something.

We get busy setting up for the duct blaster test. For this, all the heating registers are taped off and a fan is connected to the return air register in the ceiling of the hallway. We are going to blow air into the duct system, both supply and return ducts are included in this test. The fan is turned on and increased slowly to eventually reach top speed. Well, thats a fine howdy do. Seems the ducts are so leaky that the monometer will not even begin to provide a reading. This means that total duct leakage, both to the inside and to the outside, is off the charts. I see energy savings in this homes future.

By combining the blower door with the duct blaster, we can run a test that will separate out duct leakage to the inside from duct leakage to the outside. Just because we did not get a reading on total duct leakage does not mean we can not get a reading on duct leakage to the outside. The blower door fan is set on reverse so we can blow air into the house. The duct blaster is readjusted and bingo, a measure of duct leakage to the outside of the house measures 880 cfm. I can taste that clam chowder now. Nathan does away with his levis and sports a nifty pair of basketball shorts.

To continue our quest to locate the leak, we head down to the furnace and tape off the furnace filter and stick it back in the furnace. Now we can perform the duct blaster test again and test just the return air ducts for the leak. By taping off the furnace filter, we separated the return air ducts from the supply air ducts. We can now test them separately for leakage. Testing just the return duct, the duct blaster, once again indicated a leak so large that a measurement figure was not given.

We left the duct blaster fan running and headed out to inspect the return air duct system with a fine tooth comb. It was not long before Jay, who had gone back into the attic, was setting off leftover fireworks. He knew how much I was looking forward to that clam chowder.

The return air duct went from the ceiling register to a metal box that sat over an open chase that went from the attic downward, behind the bathtub wall, to the basement, where it connected back up with the furnace. Most of the air from the duct blaster was coming back up into the attic from that open vertical wall space. The heating contactor, when the house was built, used the framing space behind the bathtub wall as a return air duct. He did this without sealing the top of the wall cavity or the plumbing access holes. So for years, the homeowners have been heating the attic and providing a warm place for a cat or two to build an ever expanding trail system. Bring on the Clams.

When we have a contractor seal the top of the chase around the metal return air box and stop the air from escaping to the attic, we will see the reward of a lower electric bill and a more efficient, comfortable home. Sealing a homes heating ducts is recognized as one of the most cost effective measures to a lower power bill. With the heating ducts performing like they should, I will recommend the addition of an efficient heat pump for this home. There is no use adding a heat pump and then just blowing your savings into the attic. Additional insulation will be recommended for the cat trails in the attic as well.

Ok, before I can wrap up Todays Power Trip and look a clam in the eye, let’s take a look at this leaking return air duct and consider what is happening when the furnace is off. When the furnace is off, the duct acts like an open fireplace chimney. Warm air rises, so the warmer air in the house slowly rises up and finds its way into the return air duct and flows through the hole in the duct and into the attic. Warm attic means warm cat.

When the furnace is on and the furnace fan is trying to bring air from the house back to the furnace so it can be reheated and returned to the house - what is actually happening is the furnace is bringing cold, moist, dirty cat hair from the attic, reheating it the best it can, and blowing it back into the house. The whole senareo points to one conclusion. Seal the duct.

It’s time to head for some clam chowder – I feel like I have really earned it. The score is now one loss and two wins.