How to seal your ducts

Your duct leakage can account for up to 20% of your leakage in your home. This is considerable amount in itself but is even more of a concern when you consider that in most homes the majority of the ducts are located outside of the conditioned space in the attic or crawlspace. The leakage into these spaces is costly and can create unwanted pressure differences in the home.

Locating the Leaks

The first step in eliminating the leaks in your duct work is to find them. This can be done in several ways but some are easier than others.

1. Visual inspection: All steps in finding the leaks will involve this process. You need to visually inspect the ducts to find any visible separations, penetrations or dislocations in the ducts. Some may be obvious while others may be hidden. Look for areas where duck tape may be failing (yes is it duck and no it should not be used to seal duct joints.), at locations where two ducts meet, around the boots in the floor or ceiling and at the trunk line.

2. Duct blaster: You can have a professional perform a duct blaster test on your duct work. This will let you know how much leakage is in the duct work but by itself it does not tell you where the leaks are. You can however have the professional use theatrical smoke to fog your duct work. This will allow you to see where the leaks are as the smoke will exit at the leaks.

3. Panning: Again a professional is needed for this. A professional will use a blower door and a pan to test your ducts to see which ones are leakier. This method can help isolate problem ducts but it does not have the ability to locate the leak itself.

Fixing the leaks

Once you have located the leaks you need to fix them. First you need a few supplies. These are:

1. Mastic- a material used to seal the ducts
2. Cheep paint brush-used to apply the mastic
3. Fiberglass tape-used with the mastic to seal the joints
4. Large zip ties- used to secure the inner and outer layers of the duct work
5. Duct-you may need to replace torn sections.

Duct Joints:

If you have leaks at the joints of the duct work you will need to seal these joints with mastic. This will be where the majority of your leaks are so this is the most common fix. First remove any old tape form the joint and then remove the outer layer of the duct. This is if you have a flex duct. If the inner plastic layer of your ducts is not secure you can use a zip tie to secure the inner duct. Next apply a large helping of mastic to the inner layer of the duct. You can then slip the outer layer back over the duct. Some individuals like to also secure the outer layer as well using the zip ties. You will then mastic the outer layer as well using the same technique you used on the inner layer. Make sure you pull the insulation (outer layer) over any boots or collars.

Disconnected Ducts:

If you have any fallen or disconnected duct work you will reconnect the duct work in the same manner as described in the above step.

Metal ducts:

This covers both the metal supply ducts and trunk lines. You will follow similar steps as in the duct joints section however you will use metal sheet screws to secure the duct if needed. Also you may have some gaps larger than ¼” and will need to use the fiberglass tape along with the mastic.

Torn ducts:

Unfortunately flexible duct work will tear. If this happens you may not be able to repair the duct and will need to replace the whole run or just a section. If you are repairing just a section make sure you use metal joints at both ends of the patch and use the same techniques as in the duct joint section.

Alternative methods:

There are alternative products and methods to sealing your duct work. These include mastic tape and foil tape. Mastic and mastic tape is best used on duct work but foil tape can be used to seal items that need to be routinely opened like your air handler.

There is also an alternative method of sealing that a professional can do. This involves spraying an adhesive/sealant through the duct work. The sealant finds its way into the leaks and seals anything up to a ¼”. This can be a cost effective way to seal the duct work if you have several small holes.

Don’t “crank” your dial on your thermostat.

Moving the temperature setting higher up on your thermostat does not make you home heat up any quicker. If you have a heat pump move your thermostat 2 degrees at a time to help conserve energy. If the thermostat setting is raised greatly the heat pump will use your heating strips to heat the home costing you a lot of money.

How to seal plumbing and electrical penetrations

If you have been following along for the last few weeks chances are you may have already addressed the penetrations that we will talk about this week. Plumbing penetrations, vent fans, chimneys and other major penetrations may be obvious leaks or they may create leaks in other parts of the home and you don’t realize where the source is.

There are two types of leaks direct and indirect.

Direct leaks are leaks that occur directly at the wall penetration. An example of this may be a dryer vent or door.

An Indirect Leak is one in which the leak occurs at one location and the air exits at another. In this situation the air flows through holes and spaces in the wall cavity. An example would be a leak that occurs where a plumbing drain line enters the home but exits at an outlet.

Indirect leaks are one of the most common and problematic because you don’t know where the entry point is. To eliminate this you must seal all openings to the home.

Plumbing and Electrical:

In newer homes most of these penetrations will already be sealed due to code. However some may have been missed and there are a lot of older homes so we will visit how to correct them.

Electrical are the easiest. Using some fire caulk or silicone caulk depending on the situation you just have to locate the holes and put in some caulk. Fire caulk is required by code in new construction where wires or pipes penetrate floors and ceilings. If you have a larger hole you can use foam to seal it but in most cases electrical holes will not be much larger than 3/4”. Most of your penetrations are going to be in the crawlspace, basement or ceiling. Very few will be on exterior walls.

Plumbing penetrations may require a variety of fixes. If the hole is small, like with supply lines, you can caulk but if they are larger will need to use foam or rigid foam board to cover the gap. Foam will usually be fine around drain lines and vent pipes. You may find a large hole under your tub though. In this case you can use rigid foam board to cover the hole and use an adhesive or spray foam to affix it.

Vents and Fans:

If you have vent fans in your bathroom you are likely to have a large leak at this point. Often times the drywall will be cut larger than the fan box. This can be sealed using either spray foam or caulk depending on the size. Hopefully most will only need caulk but if yours needs spray foam (larger than ½”) then be careful because the spray foam may bend the fan housing if the metal is then.

Once you have the ceiling sealed you may need to look at the vent. Newer models will have a damper at the unit so that it closes and creates a seal from the outside when not in use. If yours doesn’t have this or if you still feel a leak you can install a damper in the vent at the end. This is rather easy if you can access the line as it exits the home. The dampers are rather inexpensive but they can help with this pesky leak.

Dryer vents and most other exhaust fans can also have the same problem and you can typically install a damper in them also to help out. If you do this make sure that it is not against building code or manufacturer recommendations.

Seal up your fireplace

Chimneys can be a major point of leakage in a home when the fireplace is not in use. In these situations you can do two things to help reduce this costly necessity. You can install air tight doors to prevent the chimney from drawing air out of the home or you can use a chimney pillow. The pillow is the less expensive fix and relatively easy to install. The pillow is inserted into your chimney and is inflated to seal up the opening. This prevents air from moving through the chimney when not in use. When you want to use the fireplace just pull the cord and remove the pillow.

Sealing leaky doors and windows

Doors and windows make up about 20% of your home leakage. They are also some of the easiest leaks to find and most of the time the easiest to fix. There are however a few misconceptions when dealing with them though.

First let’s take on two misconceptions with the windows and then we will look at how to fix the leaks.

1. Not all that feels like a leak is a leak.

This is especially true with windows in the winter. Because of the properties of the windows what we truly fell is the heat radiating from our bodies and the convective flow created around the window due to heating and cooling of the air. The leaks are often time minimum around the window, usually around the joints between the jamb and sash. The largest “draft” or “leak” is created again from the thermal transfer occurring between the room, windows and our bodies. This leads us to “feel” a leak when one is not there. HVAC ducts are often times placed in front of windows to stop this from occurring but we often times place furniture over the ducts and prevent this effect. Below is a drawing showing the transfers.

2. It is not always better to replace than to repair a window.

I have discussed this many times before but to once again address this, payback on replacement windows can be anywhere from 15 to 30 years. This means it takes that long to get your investment back from the savings the windows create. A good pack is 0 to 5 years and acceptable 5 to 10. Also if replacement windows are not installed correctly you may end up with windows leaker than the ones you started with. If your windows are not in that bad of shape a little caulk, glazing and weather-stripping can get them back to new.

With that taken care of let’s move on to how to correct the leaks you feel. Most of the leaks you find are going to be around the joints in the doors and windows, this being the areas where the slabs or sashes join the jambs. This can typically be fixed with a little weather-stripping. Below is a diagram showing different types.

Doors:

Most new doors have weather-stripping already installed but it can wear out sometimes. The best thing to do in this case is to remove and replace the weather-stripping. This is an easy task and material is inexpensive.

Sometimes the door does not have weather-stripping. If this is the case you can replace it with a metal tubular strip. This strip installs on the door stop/jamb and allows you to adjust the strip a small amount to the door to get a good fit.

Sometimes the door will not have a good fit in the jamb or against the weather stripping. This can be corrected in most cases by adjusting the striker plate to allow the door to close further in the jamb.

When repairing the door don’t forget the sweep. Some doors have them and these can easily be replaced if needed. Others will need on installed. This is a simple process and there are a wide variety of them. The most common can be seen above in the diagram. One of the most efficient but difficult to install is the spring loaded. These are hard to locate and require some expertise to install.

Windows:

Like doors windows tend to leak at the joints. If you have old single pain windows with individual lites you will probably want to consider having them re-glazed and a storm window if they are leaky. The storm window will also help with the energy efficiency of the window and they typically have a better payback than replacement.

The first step with windows is to ensure that you have a tight fit against the top and bottom jambs. Weather-stripping is easily installed and there is a variety of types. You can use a peal and stick foam or a tack on metal strip. If you are using the peal and stick make sure you have a clean surface before applying.

If you have a leak in the middle between the two windows you can again use a peal and stick or tack on depending on the window. Your clearance will be less than the top and bottom so the weather-stripping cannot be as thick.

Finally for the sides, your fix for this will depend on the manufacture. For older windows you may have to use a spring metal. If you have older style windows that still have weights you can get covers for the holes where the ropes go through. For newer windows it may simply be a leak in the track and manufacturers have caps that can stop these leaks.

Also don’t forget to make sure your lock is in good shape and closing tight on your window. Your lock can help keep the window sealed at the top and bottom.

Use Solar Powered Lights

Most of your landscape lighting is used for accent lighting or safety. You can commonly find these lights powered by photovoltaics in your local home stores. The lights work well in areas that receive sunlight and can cut your electrical cost. They also are easy to install and don’t require any wiring.

How to Seal the Home Envelope

After you've taken the time to find all the leaks in your home you have to get rid of the leaks to make a difference. In most cases this is as simple as sealing the leaks using caulking, weather stripping or spray foam insulation. I typically recommend starting with your ceiling and then working your way down.

To help you with this process, here are some typical leaks sites, based on location, and how to correct them:

Ceiling:

1. Recessed lights: In most newer construction homes, recessed lights will be at least insulation-contact approved, but some may be ICAT- or insulation-contact air tight. This means that they don’t allow air to leak. One of the problems with recessed lights is that they may be ICAT rated, but the wrong trim kit installed. Most of the time, if your light is leaking, you can replace the $5 trim kit with an airtight one, and it makes a huge difference. If this is not the case, you can either replace the light with an ICAT or install a preformed cover that creates an airtight seal around the light. These covers can be ordered typically from the same Websites that sell battic covers.

2. Attic Stairs: Like recessed lights, your attic stairs are a large leak site. To seal these, and insulate, you can install a battic cover. These covers can be bought or built. If your stairs are old and don’t fit tight you may also want to consider replacing the stairs to help get a better seal

3. Bathroom Vents and Lights: The leaks at these typically occur due to a gap between the boxes and the drywall. You can simply caulk or foam the gap. Bathroom vents can leak at the duct. In newer models, this is reduced with a damper that opens and closes with operation. This damper can get stuck or may not seal completely. If you don’t have the damper, you can replace the fan with a newer model, or you can install a damper at the end of the duct where it exits the home.

4. Chimney Chases: Chimney chases often go from the first floor all the way to the attic without being sealed. While it is not advisable to insulate around the chimney due to fire hazards you can seal off the top of the chase using metal and fire caulk.

Interior/Floor:

1. Doors and Windows: Most of the leaks in the walls will occur at either the doors or windows. This can be corrected with weatherstripping and a few other techniques. Due to the various ways to correct, I will address how to correct these leaks in a separate article.

2. Plumbing: These leaks are simple to correct. They will typically occur at gaps between the pipes and drywall. You can correct this by caulking or foaming the gap depending on the size.

3. Electrical Outlets: These only account for 2% for your total leakage, so I typically say not to worry about them at first, but they are an easy to fix. Special gaskets can be installed behind the cover. To get a full seal, you have to use safety covers to seal the outlet holes.

4. Duct boots: Ducts will get their own article, but the boots fall under the envelope. The boots are the metal items that you see coming through the floor or ceiling (yes, these can also fall under the ceiling section). Since the leak is occurring due to the gap between the boot and the floor/ceiling, these leaks are not really in the ducts themselves. To fix this leak, you can either caulk, use foil tape, or mastic the gap.

Unfinished Basement/Crawlspace:

The basement will have a lot of the same leaks as the home, so you can follow a lot of the same steps as above. Also, if the insulation is on the basement ceiling, you may want to treat it more like a crawlspace. My advice is to seal the basement as if you were going to finish it, but time and money may dictate otherwise.

1. Rim Joists: If your rim joists are not insulated, you can seal and insulate them using spray foam. The amount of foam required is more than the standard can foam is capable of handling, but canister kits are available for large jobs. Rim joists in the crawlspace are typically going to have insulation in contact with them, and you can sill penetrations in the floor so sealing these may not be as high a priority in that situation.

2. Foundation Penetrations: These are easy to see and can be corrected by filling the gaps with spray foam. Again, depending on the construction, these may not be as important for air sealing when in the crawlspace. However, they should be sealed to help prevent pests from entering the crawlspace.

3. Floor penetrations: In the crawlspace, these may be a little harder to find (due to the insulation), but all electrical, plumbing, and HVAC penetrations should be sealed using fire caulk or spray foam, depending on the size of the gap. You may have already sealed a few of the gaps from the inside, but it still helps to seal from this side, also. Most of these gaps are going into wall cavities. The air in the cavities can find more than one exit, so stopping the source of the air helps tremendously.

Use a rain barrel.

While this energy tip may not relate to electricity or gas, it relates to another resource that can be overlooked. It can also save you money if you pay for your water! Use rain barrels to collect water from your roof or other collection systems, and use this water to water you plants and yard. Barrels can be purchased or constructed.

How to Find Air Leaks in Your Home

You will most often notice leaks in your home in the wintertime, as most of us are more sensitive to the cold. These leaks are typically noticed in the form of drafts around doors and windows, but can also show up around plumbing and HVAC ducts to the most sensitive homeowners. There are several sites in the home in which air can enter, and it doesn’t just enter the home in the winter! So how does a homeowner go about finding these leaks?

First, you need a way of finding them, and I have heard several different methods. Here are just a few:

1. Feel for the leaks.
You can simply feel for the leaks. This may not always be the most efficient method for finding the small leaks, but larger leaks can be found by doing nothing more than running your hand around the area that you suspect to be leaking. This is especially true on days when the temperature outside is drastically different than the inside.


2. Use a wet rags to wet your hand and then feel for the leaks around known locations.
I have never personally performed this method and don’t know how useful it actually is, but supposedly the water will help you feel for the temperature changes. Just don’t be fooled by the temperature of the water.

3. Use a candle or other smoke emitting device.
This is very similar to what the professionals do. I have seen several items used, including candles, cigarettes, cigars, and incense. With all of these, you must be careful of the burning end of the item - and this may not be the best for indoor air quality. Professionals will often use smoke-emitting devices that are made specifically for this and do not burn.

4. Have a professional find the leaks for you.
This may defeat the whole purpose of saving money by performing the task yourself, but you may find it beneficial to have a professional use their blower door to depressurize the home and help you find the leaks. Often, I can find leaks without the use of smoke by just feeling for them. You will find more leaks this way, but again, you must consider the cost. Some professionals will perform just a blower door test  without an energy audit for a reduced price.

Now that you know how to find the leaks, it helps to know where to start looking. Below is an image of where some common leaks are found in the home:

As you can see, most of the most of the leaks come from the basement and attic. These are two great locations to start! Here are some other areas to scan when you are looking for leaks in the home.

- Behind kneewalls (walls that separate the attic and living space like in a bonus room)
- Attic hatch
- Wiring holes
- Plumbing under sinks
- Bathroom fan vent
- Recessed lights
- Furnace flue or duct chaseway (the hollow box or wall feature that hides ducts)
- Basement rim joists (where the foundation meets the wood framing)
- Windows and doors

These are just a few sites, so take a look around and see what you may find. Next week, we'll begin covering how to seal these leak spots.

Use timers or motion sensors to turn off lights when not needed.

Motion sensors have become a common item on exterior flood lights, but they aren't often used in the home. People tend to leave lights on when they are not in the room; by installing motion sensors or timers in rooms such as the bathroom, storage rooms, garages and closets, you can save money and worry.

Sealing Up Your Home

Sealing air leaks in your home can have the quickest payback of all the energy saving repairs that you do! According to the EPA, you can save up to 20% on your heating and cooling bill (10% of your annual utility bills) by sealing and insulating. Most of the work can be performed by a handy homeowner on a Saturday with some caulk, foam, weather stripping, and sweat.

When you look at the air leaks in your home, they break down something like this:

As you can see, the perimeters of your home have the most leaks, and the outlets have the least. To group all these items into a short article would not do them justice, so over the next few weeks I will go over how a homeowner can locate these leaks and correct them.

This week, we will go over some of the basic items that you will need to correct these items; in the energy tip of the week, I'll quickly cover what is, in my opinion, the least important but sometimes the easiest to fix: electrical outlets.

Supplies:

1. Spray foam: This comes in convenient cans that make application, while somewhat messy, rather easy. Dow is the manufacturer of the most commonly seen cans. They make three basic types: big gap, regular, and low expansion. Each of these has its application; the directions on the cans are rather self explanatory, but for sake of being thorough in explaining the uses, I will give a brief synopsis.
Big Gap: This is used to fill large gaps typically over 1 inch.

Regular: This is the basic foam type and will typically be used more than the others. It can be used in most all applications; however, there may be other types better-suited, depending on the use, such as the big gap or low expansion.

Low Expansion: This foam does not expand as much as the others and will typically be used in small gaps, especially around windows and doors. Doors and windows are susceptible to sticking as the foam expands and deforms the frame. It helps to prevent this from happening.

2. Caulk: There are 3 basic kinds of caulk, ranging from silicone, a silicone polymer mix, and latex. I recommend silicone, as it lasts longer and is flexible.

3. Backer Rod: This is an item that is used to fill large gaps for caulking when spray foam will not work. Simply insert and caulk over.

4. Weather Stripping: This will vary by application, with there being several different types. As I'll be going into doors and windows more in-depthm I'll keep this short. Below is a picture of a couple of types:

5. Foam gaskets: There are several gaskets that can help seal around objects in the home. The majority of them come on trim kits, such as fan covers and recessed light trim kits, but you also have items such as the outlet cover gaskets. These do pay a crucial role; other than using this as a lead-in to sealing outlets, it is worth mentioning because many individuals will forget to install the gasket or will tear it in the installation.

Seal your electrical outlets.

As you see the outlets only make up 2% of your total leakage in the home. While this is very small (and I typically recommend these as a last step), they are rather easy to fix - especially if you are building a home.

To stop this leak during construction, there are two steps. One is to seal the penetrations in the walls (which I'll cover later), and the other is to seal the penetrations of the wires into the outlet box. You can also use air-tight gaskets around the box.

If you have an existing home, you can seal the outlets using the gaskets many are familiar with. However, these will only seal around the outlet and not the outlet holes. You will typically need to use the child proof covers to totally prevent air leakage into the home through the outlets.