I remember my old home quite well. It was a frame house built in the early 1900's. The windows were original wood double hungs with no weatherstripping. It had an uneven stone foundation with no sill sealer (Sill sealers are foam products used at the transition point between masonry foundations and wood framing systems. They stop air leaks.) In other words, there were massive air leaks into and out of my old home.

The funny thing about air leaks (really it's not so funny) is they are two way. If you feel a cold blast of air leaking around a window, door, baseboard, etc., there is an equal amount of heated air escaping to the outside. If this didn't happen, your house would blow up like a balloon.

Temperature is Everything

This exchange of air in the winter months can cause humidity problems inside houses. How, might you ask?

As air gets colder, it becomes denser. The molecules of oxygen, nitrogen and other gases get squeezed closer together. There is less room available for other things such as water vapor.

I know, I know what you're saying, "But Tim, the weatherperson says that the relative humidity is 60 percent or higher on an almost daily basis. In the summertime, this humidity level is very uncomfortable." Hey, you said the key word.......relative!

Weatherpeople measure humidity as it relates to temperature. For example, let's say it is 20 degrees F outside and the relative humidity is measured at 60 percent. If you were to "capture" say 10 cubic feet of this outside air, and then simply raise its temperature to 72 degrees F, the relative humidity of this same air would drop to around 8 percent! That is really dry.

Static Zots = Energy Loss

Normal daily activities release large volumes of water into the air inside our houses. If you shower, wash clothes or dishes, hang clothes in the basement (now that's a good idea!) to dry, etc., you release water into the air. In fact the air you exhale from your lungs humidifies the air (not to mention your perspiration.) Anyway, people who live in newer, well-built, air tight homes have noticed that they rarely, if ever, get zotted by static electricity. This is so even if they do not have humidifiers connected to their heating systems.

This lack of static electricity means that the humidity level inside their houses is higher, more comfortable. It also means that this humid air is not being diluted by drier, outside air. This means there are fewer air leaks. Want higher indoor humidity and lower fuel bills? Start by finding and fixing air leaks!

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Humidifier Manufacturers

The following manufacturers make humidifiers. Some of these companies have very unusual names. You would never think that they make humidifiers. I suggest that you call them and ask for free descriptive product literature. Not only will they oblige you, they will probably tell you the location of the nearest distributor. Be sure to ask tough questions about how easy it is to change the filter pads. My humidifiers are tough to work on. You have to take the whole thing apart to get to the filter pad. My manufacturer has since corrected this problem. However, I'm stuck with the older models.

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The following indoor relative humidity settings should provide you with a good comfort level. Almost all humidifiers come equipped with a humidistat. This device works just like your thermostat. You set the humidistat to a desired humidity level. When the humidity reaches that point, the humidifier stops working.

Suggested Indoor Humidity Settings

The following table gives you an idea of just how "dry" outside air is when it is brought indoors and then heated to room temperature. If you have low humidity in your home, you have air leaks. The dry outside air is mixing with your humid air and lowering the overall humidity. Plug your air leaks and you may not need a humidifier.

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Can you imagine the mess I once came upon when I entered a basement where the dryer had been venting inside for about eight years? There was lint everywhere! It was a huge mess, not to mention an incredible fire hazard. Cotton fibers were everywhere.

The vent had come unhooked from the bottom of the dryer and the homeowner didn't have a clue. They thought the stuff was cobwebs. It was believable as the accumulation was slow and they had grown accustomed to its presence. It freaked me out.

Basement Venting - Easy!

Getting dryer exhaust from a basement is a piece of cake. It usually involves two 90 degree bends and sometimes three. Often there is only 10 to 15 feet of pipe. Many people go the easy route and choose the plastic flexible variety. This tubing does not comply with current code standards. I have always been a smooth metal pipe man myself. It is easy to work with and fits together in a flash. Cutting it with tin snips is also a cinch.

I have found that it is often best to vent fans and dryers through the roof. I urge you to watch this video of mine to see how easy it is to install the correct vent-cap flashing on a roof. Have no fear - if done right you will have no leaks.

The Vent Cap

Many people are familiar with the wall vent terminal for dryer vents. The inexpensive ones only have an opening that is about 2.5 or 3 inches big at its widest point. These are loser dryer vents. Try to locate those that have a 4 inch opening or use the ones that have the mini-louver doors. These types offer the least air flow resistance.

The wall dryer vents can't be used on a roof location. You must get a roof vent cap that is designed to shed rain water. These vent caps also have great built-in flashings. The best part is that they are inexpensive.

Venting Through a Roof

I have installed quite a few dryers in second and third story rooms. The people always wanted me to vent the dryers through the roof once I gave them the option. It is a little more work but it is not terribly difficult. It is no more work than installing a plumbing vent pipe. The key is to locate it in such a way as it is least visible from the ground. You don't want lint fibers up on the roof to greet your visitors, do you?

Clamps and Tape, Not Screws

When installing pipe between the dryer and the vent cap, use the special large clamps that secure the pipe to the fittings. If you screw metal pipe together, the screws can catch lint over a period of time and actually cause problems.

The seam between metal pipe and fittings should be taped with the foil faced duct tape. This is REAL duct tape, not the imitation stuff you think is duct tape!

You buy foil faced duct tape at HVAC wholesale distributors or places where metal ductwork is sold. It really sticks to metal pipe and the tape is often reinforced. It is the most wonderful tape I have ever used for securing metal pipe. It makes off-the-shelf imitation duct tape look sick.

Insulate the Pipe

If you decide to vent your dryer through the roof, you absolutely must insulate the section of metal pipe that is in a hidden spot where cold temperatures can surround it. Failure to do this will lead to massive condensation and leak problems. If you live in a warm climate, you don't have to insulate the pipe at all.

Be sure to wrap the pipe with at least three inches of fiberglass insulation from where it penetrates the ceiling below all the way up to the underside of the roof. Use the wonderful foil duct tape to secure the insulation and tape the seams completely.

Hanging Pipe

The best way to hang horizontal runs of dryer vent pipe is to use the plastic J hooks designed for four inch smooth, rigid metal pipe. These heavy duty hooks have prepunched holes that allow you to quickly attach them to wood floor joists or any surface that will accept a nail or screw. They are simply the best!

Different Pipes

I have had to use four inch rigid metal pipe on occasion to vent dryers through roofs. I chose this pipe because I could get it in long lengths without a seam. I was able to insert it through a roof hole all the way down to the second floor dryer location.

This type of pipe has a very smooth interior surface that offers minimal resistance to air flow. It is also corrosion resistant.

Current code calls for a smooth, rigid metal dryer duct of at least 4 inches and no longer than 25 feet. Be sure to check your local codes for any additional requirements or restrictions.

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Clothes Dryer Vent Tables

Properly connecting a dryer to an outside vent terminal is not as simple as it might seem. You need to be concerned with the total length of run of the pipe, the type of pipe you use, how many bends are in the pipe, and the design/shape of vent terminal at the end of the pipe.

The dryer blower only produces so much energy. This energy is offset by friction within the vent pipe. This is why you must be concerned with the total length of the pipe. Ninety degree angles also create friction. Each bend equals the friction the air would encounter if it ran through an additional 10 feet of straight pipe. Smooth metal pipe offers less friction than flexible pipe with lots of little ridges within the pipe. The vent cover shape and design is important as it also acts as a partial dam or blockage to the exiting air. A vent with a wide mouth opening say four inches or so or one with the little louver doors that swing wide open offer the least resistance. The smaller the vent opening the greater the amount of final resistance.

Use the tables below to calculate how far your vent can be from the dryer. Pay attention to the type of pipe you have and the vent configuration!

Vent cap with wide four inch opening or mini-louvers and smooth metal pipe

• Total Pipe length can be 64 feet with No bends

• Total Pipe length can be 54 feet with 1 bend
• Total Pipe length can be 44 feet with 2 bends
• Total Pipe length can be 35 feet with 3 bends
• Total Pipe length can be 27 feet with 4 bends

Vent cap with narrow 2.5 inch opening and smooth metal pipe

Vent cap with wide four inch opening or mini-louvers and flexible ribbed pipe

• Total Pipe length can be 36 feet with No bends

• Total Pipe length can be 31 feet with 1 bend
  • Total Pipe length can be 27 feet with 2 bends

  • Total Pipe length can be 25 feet with 3 bends
  • Total Pipe length can be 23 feet with 4 bends

  Vent cap with narrow 2.5 inch opening and flexible ribbed pipe

  • Total Pipe length can be 28 feet with No bends

  • Total Pipe length can be 23 feet with 1 bends
  • Total Pipe length can be 19 feet with 2 bends
  • Total Pipe length can be 17 feet with 3 bends
  • Total Pipe length can be 15 feet with 4 bends

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Roof Dryer Vent Hood Manufacturers

You can go to any home center store and get an inexpensive and probably ineffective dryer vent kit. Some of these same stores may even stock the specialized roof dryer vent that I have on my own home. However, I wouldn't bet the ranch on it.

I have had the best luck locating these special roof vents at light fixture showroom stores. These places almost always handle bathroom and kitchen exhaust fans as well. The bathroom and exhaust fan manufacturers just happen to make the wonderful specialized roof dryer vents too!

In fact, since I installed the one on my roof they have improved them. My roof vent is made from metal. It had a wonderful painted finish that has now all but washed away. The new vents are made from heavy duty plastic and have a great insect and varmint screen. The flapper is also quite nice. The best part is that they are virtually leakproof if installed correctly. My roof vent has never leaked even in the worst blowing rain.

Call both of these manufacturers and get a catalog. Look under bath fan accessories and check out the roof terminals caps. You should have no problem finding out where to buy these great items.

• Broan-NuTone LLC
  
  
• Duraflo

I have found that it is often best to vent fans and dryers through the roof. I urge you to watch this video of mine to see how easy it is to install the correct vent-cap flashing on a roof. Have no fear - if done right you will have no leaks.

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Have you ever gone up into a hot attic? I mean a really hot attic. The heat can be stifling. This heat is doing everything it can to get through to the inside of your house. Adding attic insulation is a great way to offset this heat. Moving air through an attic can help remove some heat, but only if the air comes from the outside of a home. This of course can be a challenge.

Ventilation

Attic ventilation is a hot topic - no pun intended. Those of us in the industry have become more aware because of the changes in building practices in the past 25 to 30 years. Prior to the mid-1960's, attic insulation and ventilation was not really important. Rising fuel costs, rapid advancements in window technology, vapor barrier use and environmental issues have made us more aware that insulation and ventilation are important. They can save you money and help to preserve the investment in your home.

Continuous ridge and soffit ventilation is a good system. It works for free using the natural forces of Mother Nature. Every time wind blows across your roof it creates a mini low pressure area or vacuum. This suction gently moves air through your attic space as long as replacement air can easily get into your attic. Since air desires the path of least resistance, you need to make sure that soffit ventilation entry points are open and prolific so that the air doesn't come from inside your home.

The only time air from inside your home can be used is when you operate a whole house fan. These great products are used when you do not have air conditioning, or when the outside air is cool enough or at a low enough humidity so that it is comfortable.

If you air condition your home, the last thing you want is air conditioned air finding its way into your attic and out the vents! This is why powered attic ventilation can be harmful to your pocketbook.

Learn how to better insulate your home and read this additional information about continuous ridge and soffit ventilation.

Related Articles:  Powered Attic Fans-Insulation Facts, Continuous Ridge & Soffit Vent Manufacturers, Insulation Values

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Insulation Values for Existing and New Homes

Do you want your house insulation up to minimum standards? If so, then you must read the U.S. Department of Energy's Insulation Fact Sheet. It contains information on the types of insulation you should have in your ceilings, walls and floors. Remember, you can add more if you think you will get a benefit. However, don't compress batt insulation. This means do not try to squeeze a nine inch batt into a six inch cavity. Use some common sense.

For a more accurate and simpler method of determining your insulation needs, try the U.S. Department of Energy's Interactive ZIP Code Insulation Program, which uses your zip code and some information about your house to tell you where to add insulation. The program was developed by the Energy Division of the Oak Ridge National Laboratory. State and local codes in some parts of the country may require lower R-values than the DOE recommendations, which are based on cost-effectiveness.

Related Articles:  Powered Attic Fans-Insulation Facts, Continuous Ridge & Soffit Vent Manufacturers, Ventilation - Keeping Home & Attic Cool

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Continuous Ridge and Soffit Vent Manufacturers

Check out the web sites of the following manufacturers and you will find some great information on ridge and soffit ventilation products. You will be amazed at the variety of products. 

Related Articles:  Powered Attic Fans-Insulation Facts, Insulation Values, Ventilation - Keeping Home & Attic Cool

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Cooling doesn't have to come from air conditioners. Just sit under a paddle fan and feel what simple air movement can do. Of course, if the dew point is above 70 F, moving air doesn't do much good, you still feel sticky. Fortunately, many parts of the nation don't have oppressive humidity, and whole house fans can really do a nice job of cooling a house and its occupants on hot summer days.

Creating a Breeze

My personal experience with whole house fans allows me to tell you that these machines will do a great job, if you monitor which windows in your house you open and close to feed the fan's appetite for air.

The simple trick is to open the windows in the rooms you are occupying at that point in time. You want a breeze to flow past you, so that you benefit from the fan's work. It is important that you keep windows closed or nearly closed in the rooms that do not have occupants. Why? If you open all of the windows in your house, there is a good chance that just a little air will flow through each room. On the other hand, if you open the windows in just one room, you might create a moderate windstorm in that area as all of the air being sucked by the fan makes its way through the room and up to the attic.

It will take a little practice for you to get a good air flow through your house. Trust me, it will not take long to figure out how to create a smooth flow of air through many rooms.

Types of Drives

There are two types of ways that the fan blades are driven. Many fans have a direct drive connection between the blades and the motor shaft. This method frees you from ever having to adjust a fan belt or replace a broken belt. The other common drive mechanism is the traditional fan belt. A belt driven fan allows the motor to be offset from the blades. A high quality fan with this setup can last for years with little attention. Fan belts made today can resist years of use and high attic temperatures.

Clean the Fans

Whole house fans move vast amounts of air and in that air is always dust. This dust accumulates on the fan blades, the motor and all other surfaces. You can extend the life of the fan motor if you vacuum off this dust at least once a season. Dust that accumulates on the motor housing causes the motor to get hot. Hot motors simply burn up long before their time.

Which Velocity?

When you start to look at fans, you are going to see a big difference in capacity. The air that the fans push is measured in cubic feet per minute (CFM). The opening bid on the minimum amount of air any one moves is 1,000 CFM. You can get fans that move nearly 7,000 CFM.

Moving lots of air in a short amount of time creates a penalty. This penalty is noise. If you have ever been near a large high velocity whole house fan, the noise they create can be deafening. Obviously, the farther away you are from the fan, the noise decreases.

The solution to this problem is to consider low velocity - or low CFM fans. To get comfort from a low velocity system, you may have to fine tune your open and closed window program, but that extra effort may be music to your ears.

Timers

Many people really like whole house fans for the comfort they deliver at night. In fact, they can deliver way too much comfort and actually make you cold. The fan manufacturers know all about this and deal with this by using timers. There are a variety of different timers that allow you to control the fans' on and off cycles and how long each cycle lasts. A timer with your whole house fan is a must.

Ask Around

Ask your friends, neighbors, co-workers if they have a whole house fan. Visit them to see how it feels and sounds. Don't operate it if the house is closed up and ashes are in the fireplace. The voice of experience talking!

Companion Articles:  Cooling With Mother Nature and Whole House Fans,  Whole House Fan Installation Tips, Whole House Fan Sizes and Manufacturers

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