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.
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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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There are several manufacturers of whole house fans. Some are small companies and other are huge. There are also some in-between companies. The actual fans are not really complicated. They consist of a housing to support an electrical motor and the fan blades. The better fans have better electric motors and better balanced blades. As you might expect, these fans cost a little more.
I have listed some average sized fans and their capacities below. The fans I have listed that are made by the Broan company are considered high velocity fans since they push more than 3,000 cubic feet of air per minute (CFM). I have also listed a low velocity fan after the following table that has two separate sets of blades. This one is made by Tamarack Technologies.
| Model # | CFM | Maximum House Square Footage |
|
2200 |
3,300 |
1,100 |
|
2224 |
3,600 |
1,200 |
|
2230 |
5,100 |
1,700 |
|
2236 |
6,850 |
2,300 |
The Tamarack Technologies fan is the HV1000. It has a neat special insulated cover that closes over the fan blades when the fan is off. This feature eliminates cold drafts in the winter or hot air from entering the house if you are using air conditioning.
Whole House Fan Manufacturers
Here is a list of companies that still make whole house fans. Get some free product literature and a list of suppliers in your area!
Companion Articles: Cooling With Mother Nature and Whole House Fans, Whole House Fan Installation Tips,, Cooling Comfort With Whole House Fans
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Whole House Fan Installation Tips
Most of the newer whole house fans are designed to be installed with minimal alterations to attic framing. Special models are made that can actually fit over and around attic trusses that have been placed at 24 inch centers. Don't make the mistake of buying a fan that fits your framing but NOT your house. An undersized fan simply might not move enough air.
Exhaust Air Ports
Pay attention to the instructions that come with the fan. They will undoubtedly mention attic exhaust area and will represent this number in square feet. Do whatever is necessary to achieve or exceed this number. There is a very good chance that you will need to install extra roof vents to meet this important requirement. If you don't know how to install a roof vent without causing a leak, you will need a roofer.
The size of the hole cut in the roof is not the true ventilation area. Often the instructions refer to net free area. This is usually 50 percent of the actual hole that is cut. Why only 50 percent? The screening, louvers, rain covers, etc. that are a part of roof and gable end vents create resistance to air flow.
Dealing With Insulation
Many attics have blown-in insulation. Powerful attic fans can create a virtual snow storm in attic spaces, if you don't plan ahead. Often, you simply need to construct a simple plywood box or sides around the attic fan. This will deflect air up towards the roof and stop insulation from being sucked into the high speed air flow immediately adjacent to the fan.
This box can also serve another valuable purpose. If you take your time and cut all of the pieces so they are flush and level once installed, it makes a superb platform to support an insulated cover for when the fan is not used. Many of the ceiling louver kits allow vast amounts of cold air to drop down into the house during winter months. You can cover your attic fan from the top with strips of plywood that are then covered with batt fiberglass insulation. If you are really handy you will glue pieces of foil faced foam to the sides of your attic fan deflector box to stop heat loss through the sides of the structure.
Electric Needs
If you purchase a low powered fan, you might not need a separate circuit for the fan. In any case, you need to follow the National Electric Code with respect to fans like this. It may say or your local inspector demand that a separate circuit be installed. If your builder or electrician was thinking ahead, then it will be easy. I always installed several blank or empty conduits from the electric panel to the attic area to accommodate future wiring needs. If you don't have one, try to find where the large plumbing stack travels up from the basement area to the attic. Often the plumbers leave enough space between the pipe and the framing to allow you to drop a string and pull a wire.
Trusses
If you are getting ready to cut a truss to make your fan fit, STOP! You can't cut a prefabricated truss without seriously compromising your roof structure. Go to plan B, or call in an experienced carpenter who can tell you your options.
Companion Articles: Cooling With Mother Nature and Whole House Fans, Whole House Fan Sizes and Manufacturers, Cooling Comfort With Whole House Fans
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Cupolas Can Serve Double Duty
Cupolas are indeed unique architectural features. They go well with certain homes and not so well with others. Often they seem to look best on an accessory structure like a garage or a shed. The one I have on my garage would look very funny on my house but it seems very attractive on the garage. Isn't that weird?
Decorative or a Workhorse?
Some cuploas end up being simply decorative. Even though they are built to act as ventilators, the person installing them decides to simply make the necessary angle cuts and just attach the cupola to the roof. In my case I wanted the cupola to serve as an excellent rooftop ventilator. It sticks up in the air and any breeze that passes by helps to siphon hot air from my garage attic space. To accomplish this, I had to cut a hole in the top of my roof. The cupola sits over this hole. You can actually climb into the attic and stick your head up inside of the cupola, much like an army tank turret. Hmmmmm, I better not mention that to my son or he will be up there in a flash surveying the countryside for the enemy!
Weathervanes
You need to be careful when you buy a weathervane. Some of them are quite decorative and they look nice, but they are not very functional. The balance of the vane is critical. If the top part of the weathervane is not well balanced, the vane will have a tough time reacting to changes in wind direction. Only the strongest gusts will move it. The best weathervanes are often equipped with a ball bearing. The bearing sits between the top of the iron shaft and the top of the weathervane tube that slides over the iron shaft. If the weathervane is well balanced, it takes very little to get it to rotate.
Companion Articles: Cupolas, Cupola Installation Tips, Weathervane & Cupola Manufacturers
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Cupola Installation Tips
Most of the cupolas come with installation instructions. Some are well written and others assume you have been a full time carpenter for about 15 years or so. Keep in mind that installing one of these devices is not a very easy job. You need a certain degree of skill and you need certain tools. You also need to be careful since you are working up on a roof.
The first thing to do is cut the base of the cupola so it matches the roof pitch. Be aware that certain cupola bases will only work for certain maximum roof pitches! It is a good idea to determine the roof pitch before you start to make sure the cupola is going to work. Roof pitch is simply the amount of slope measured by calculating how many inches of drop for every foot of horizontal run.
The cupola needs to be centered on the roof. Once you think you have the correct roof pitch, why not transfer it onto a scrap piece of plywood that is the same size as the side of the cupola? Make your cuts and take the plywood up onto the roof to see if it fits. If the plywood was a square or rectangle before you started, then the top of the piece should be level when you place the cut edges on the actual roof surface. If you are satisfied with the fit, then transfer the pattern to the bottom of the cupola base and cut both sides. Take the cupola base up on the roof and see how it fits.
Flashing
If you decide to make your cupola a ventilator, metal roof flashing is a must. Do not rely on caulk to keep rain from getting under the cupola. The caulk will eventually fail.
The cupola will need to be attached to blocks that are screwed to the roof. The cupola base slides over these blocks. Metal roof flashing is installed under each shingle and butts up against the blocks. You may need help from a roofer with this!
Companion Articles: Cupolas, Weathervane & Cupola Tips, Weathervane & Cupola Manufacturers
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Weathervane and Cupola Manufacturers
You can go to home centers and old fashioned lumber yards to get a start on buying a cupola. Open your Yellow Pages and look under Brass and you will find shops that sell some weathervanes. But if you want the best place to buy both, head to the Internet. I did a search and came up with lots of companies. To save you some time I have selected just a few that amazed me with their presentation and knowledge. These companies have some very cool products!
This company has the most complete list of weathervanes I have ever seen. You want an Indian, they have it. You want a salmon fish, they have it. How about a witch on a broom, you bet! You will not waste your time here!
This company has a wealth of helpful information about cupolas, weathervanes, lightning rods, finials, etc. Do you have a big house or commercial building? They have a cupola that will fit, trust me!
Now here is an interesting company. They supply you with interesting facts, photos and tidbits about cupolas.
NewConceptLouvers
Custom Home Accessories
Companion Articles: Cupolas, Weathervane & Cupola Tips, Cupola Installation Tips
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I'll never forget that day as long as I live. It was a typical late July day here in the Midwest. I was in the midst of a remodeling job that was running slightly (right, give me a break!) behind schedule (typical). Anyway, I had to cut a hole in a roof to extend a new plumbing vent stack out to the atmosphere. For some reason, I waited until after lunch to tackle this project. What a mistake!
I poked my head above the scuttle hole. Immediately I was enveloped by hot air. I mean really hot air. It was difficult to breathe and within a period of 30 seconds I began to perspire profusely. This particular house had no attic ventilation. The air was stagnant. It took 15 minutes to complete my task. Those 15 minutes seemed like 3 hours.
I would have sworn that it was 150 degrees F or better in that attic. The homeowner happened to have a highly accurate thermometer which we used to check it out. It turned out I was wrong. It was only 134 degrees F.
Why no Ventilation Fifty Years Ago?
That's a very good question. If you are a student of older housing, you will notice that older homes rarely incorporated ventilation as a part of the roofing system. Occasionally you would see tiny gable end vents. I don't know of one old house I have ever worked on that had any form of soffit or eave ventilation.
Ventilation of homes began in earnest during the 1970's. This coincided with the increased efficiency of doors, windows and vapor barriers. We simply began to build tighter houses.
Prior to the 1970's, houses used to breathe (lose energy) very easily. Who hasn't been in a drafty old home?? Energy costs were lower. It didn't seem to matter that the old gas conversion furnace was only 45 to 50 percent efficient. Old double hung windows had no weatherstripping. Many old houses had no insulation. Air could move freely between the inside and outside of these old houses. We actually were ventilating old houses quite well. However, we found out that it was expensive!
Times changed. The energy crisis of the mid-70's shocked us into reality. Windows and doors began to be built using very good weatherstripping. Insulation and vapor barriers were applied to outside walls. Within the past 15 years entire houses have been 'wrapped' with air infiltration barriers. All of those previous paths for air exchange have been blocked. Within a matter of years, problems began to develop with houses that were suffocating. None of these problems had ever been seen before.
Old vs. New
Thousands of other people have experienced the hot attic temperatures that I encountered on that hot July afternoon. Old houses have always had the same problem. However, because air conditioning has only been around for the past 40 years or so, hot attics were simply accepted.
The same is true for older houses in colder climates. These houses rarely experienced any attic problems in the winter months. If you are building a new home or are improving and upgrading an existing older home, you can expect trouble if you do not provide adequate ventilation for your attic.
Last Chance for Air
Unless you have a state of the art air exchanger, attic areas of today's house's are the only place where air can be exchanged with outside air. It is here that today's houses must breathe. This is one of the reasons continuous attic ventilation is so important.
There are lots of other reasons why ventilation is important. Continuous ventilation helps to reduce cooling costs, validates the warranties of some asphalt shingles, reduces heating costs in colder climates, reduces chances of moisture buildup in attics, etc. Trust me, continuous attic ventilation is the only way to go.
Continuous Ventilation
If you are not familiar with building or remodeling, you might be easily confused with continuous ventilation. Older homes, and even many modern homes have used different types of vents to exhaust air from attics. A common form is the triangular gable end vents found in many older homes.
Many people have metal 'pot' vents on their roofs. These vents simply cover holes cut into the roof.
Continuous ventilation products are different. These products began to hit the market approximately 15 to 20 years ago. The first ones were metal contraptions that replaced the cap shingles at the top ridge of your roof. Besides being unattractive, they often leaked.
In addition to the ridge vents, a continuous metal strip was often (and still is) placed in the soffit or under eave area to provide a place for fresh air to enter the roof. These strips of metal would run from one end of the soffit to the other in a continuous fashion, just like the ridge vent. Is it a little clearer now?
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How Much Ventilation?
Probably less than 3 percent of the homes standing today (new and existing) have proper attic ventilation. Those that do can achieve this goal in several different ways.
The houses that have proper ventilation do so in the following way. Continuous or ample singular vents are placed at or near the top of the roof. A similar system of vents is then placed at the bottom or under side of the roof. This system works like a forced air heating or cooling system in your home. The air that leaves the upper vents is replaced by the same amount of air at the lower vents.
It is extremely important to have both upper and lower vents. This is what produces the flow through and continuous air flow in your attic. Furthermore, the vents should be installed in a specific fashion. Sixty percent of your venting area should be in the lower vents, while the remaining 40 percent should be at the top of your roof.
OK, so you understand that. Well, how much ventilation is required? Simple. The number (or ventilation area) is directly related to the size of your attic. In other words it is a simple ratio.
The amount of ventilation required depends upon whether or not you choose to use continuous or flow through ventilation. It is possible to achieve attic ventilation without flow through or continuous methods, but it is not as effective.
Let's assume you decide to go with continuous ventilation (Smart move!) Just about every model code, the Home Ventilating Institute and the FHA state that the minimum amount of ventilation required is a ratio of 1:300 (net free area). Hold on, I'll explain both.
The ratio 1:300 can be explained readily. It means simply this: for every 300 square foot of attic floor (in reality this equals the ceiling area of all insulated ceilings in your house) you need 1 square foot (free net area) of ventilation space.
Net free area is also easy to explain. Just about every ventilation product, whether it is a metal pot vent, a gable end vent or a continuous ventilation product has some type of screening or barrier which prevents insects from entering these 'holes' in your house. Well, you might not believe this, but the screening restricts or slows the movement of air through the ventilation product. So the manufacturers calculate the real air flow that goes through the hole. It will always be less than the size of the hole when using a non-powered ventilation product.
For example, most common metal pot vents that you see on roofs have a net free ventilating area of only 50 square inches. On the other hand, most continuous ridge ventilation products have a net free ventilation area of 18 square inches per lineal foot of vent.
For the formula of how to calculate ventilation area of a house, click here. This explanation illustrates how to determine the ventilation area needed for a typical ranch house.
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Calculating Ventilation Area
OK, to determine how much ventilation area you need for your house, all you need to know is the square foot area of the attic to be ventilated. Let's use the following simple ranch house for an example.
The house measures 30 feet by 50 feet. There is a 22 foot by 26 foot attached non-heated garage. In reality, the garage doesn't figure into the calculations. That doesn't mean you shouldn't ventilate it, it just means that I will not include it in my calculations:
30 feet X 50 feet = 1,500 square feet
OK so now we know the square footage of the attic area to be ventilated. Now, let's figure out how much ventilation space we need. Remember, the minimum area requirement when using a continuous system is a ratio of 1:300. So, in our example, we will divide the 1,500 square feet by 300.
1,500 square feet / 300 = 5 square feet
See how simple that was! We know we need 5 square feet total of ventilation area. Based upon just about everyone's recommendations, 60 percent (or 3 square feet) of this should be in the soffit area and the remaining 40 percent (2 square feet) should be located at the ridge of the roof. Let's see how a standard ridge vent product will calculate out.
Standard ridge vent produces 18 square inches of ventilating area per lineal foot. Our roof is 50 feet long, so using a standard product we will get 900 square inches of ventilating space. Nine hundred square inches equals 6.25 square feet. So the ridge ventilation has exceeded the minimum requirement. That's great! But what happens if we choose to use those individual metal pot vents instead? The calculations before indicated that we needed 2 square feet of ridge or upper roof ventilation. Two square feet equals 288 square inches. A normal metal pot vent produces only 50 squares inches of free net area. So, we would need at least six metal vents in addition to the lower soffit ventilation to meet minimum ventilation requirements.
If you choose not to use continuous ventilation, guess what? The required ventilation area doubles! This means that you would not have any soffit ventilation. It then means that you would need a total of 10 square feet of ventilating area. How many metal pot vents you may ask? Believe it or not, you would need 29 of those individual metal pot vents to meet minimum requirements. Have you ever seen that many on a roof before? I know I haven't!
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