We are building an ICF home in 2009.  We live in Southwestern Ontario and I am being told that if we are to spend the money on an ICF home then we need to spend the money on good energy effecient windows. 
My question is, is there such thing as a really energy effecient skylight?  It makes sense to me to use the suns free light as much as possible but I am thinking that skylights are not that energy effecient.
Also, does anyone have an opinion on North Star Windows?
Thank you everyone for this great educational forum.
Monia Butler

Consider using the efficient sun dome tube type skylights. We REALLY want to use then on my house under construction. Here is a list of suppliers of sun tubes and skylights.

Seems like a shame to build an ICF house then add skylights (assuming you are looking to be eneregy efficienct).  They allow your (paid for) heat out during the winter, and unwanted heat in during the summer.  Horizontal glazing is generally a bad idea form an energy efficiency perspoective - regardless of the manufacturer.

Sun tubes might get you the light you desire with much better energy efficiency.

Good luck,
Ed

this may have been posted in the "sun tube" list above, but companies like solatube and cira light have some interesting product alternatives.

I have 6 suntubes in my Florida house and 2 big ones in Tenn. I love them!

HAte sky lights, have 2 of thme but never again.

try suncowboy in OK, Kathy is the contact. She has a real nice product. Most of the tops and tubes are the same but her diffusers are the differance.

I have been in the skylight buisness for over 6 years.
I maybe a bit bias but I do know a little about the topic.

While I do understand that cutting a new hole in your roof and installing a skylight will create heat gain and heat loss, you must also weigh in the fact that your windows do the same thing.

If you choose the right skylight manufacturer the skylight will have very similar Solar Heat Gain Coefficients and U Values than a window.

One thing that I do know is that skylights will always give you more light up to 30% more than a window with the same glazing area.

I recommend placing electric venting skylights in strategic areas of the home to not only provide lots of natural light but remove harmful VOC's from the home and also help eliminate warm humid air trapped at the ceiling level. These areas are kitchens, mater baths, and over stairs.

Tubular skylights are great but always remember that they were designed for small areas. Large rooms may require more than one to provide the light your looking for.

Sun light is very useful and it gives natural energy to our body.

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Brook

You are absolutely correct Brook!

The Sun provides 80% of our viatimin D.
It regulates our circadian rythms(biological clock).
Proven to alleviate symptoms of SAD (Seasonal Affective Disorder).
Sunlight can boost our energy.
Studies have shown sunlight in classrooms can increase test scores, decrease absenteism, and produce better dental records for school childern.
Studies have also shown that sunlight can increase retail sales by 5%.

The average American now spends 23 hours a day indoors. We need natural light!
The most efficient way to get natural light into the home is through Roof windows or skylights.

Source(s): Heschong Mahone Group Daylighting Studies

I have 2 18" suntubes in a 1000 sqft great room. All the light you need during the day for sure!

I've read that the important part of a solar tube skylight is the diffuser. But can anyone tell me whether it matters how long the light tube is? Imagine a non-vented roof system which utilizes the attic type space under the gable as a room. There would be maybe 4 inches of roof structure/insulation, another 2 or 4 inches of furring and sheetrock, maybe 1 inch of roof cladding. So the tube wouldn't even be a foot long. Is it necessary to have a longer tube for the light to bounce around in?

Funny you should bring this up I am taking abreak from cleaning my suntube defusers.
I think the 2 main parts are the collector on roof and defusers. Mirror tubes are just the carriers.

I have several differtn makes of suntubes in various properties I own. Look around first.

Raider Bill,

If you have very little attic space such as in a attic conversion or cathedral ceiling the best tubular skylight to use would be the Flexible Sun Tunnel by VELUX. You will be able to cut the amount of tubing you need very easily. Rigid tubing will be very difficult to cut to the exact length you need.
The flexible Sun Tunnel is less reflective than the VELUX Rigid Sun Tunnel when compared in longer runs, but a very short run such as 1 foot no one could tell the difference between the two. It would take special light meters to read a difference in lumen output.

To answer you question about tubing...The longer the tube run the less amount of light the tube will produce. This among other things such as direction on roof and the reflectivity of the inner tube surface. If you need more than 12 feet of tubing, I would recommend looking at a traditional skylight. As the length of the tubing increases- the light decreased and the price increases.
*At some point it is diminishing returns.

This is the best rule of thumb(s) for any tubular skylight:
1. The shorter and straighter the tube the better performance.
2. South or West facings are best in the Northern Hemisphere.
3. Look for higher reflective tubing.
4. There are two types of tubing used a multi layer film and an electrobonded tubing.
*Multilayer film can delaminate over time from UV exposure.
5. Manufacturers tend to over estimate the square footage coverage. I have found that if you have more than 100 sq ft you may need multiple units.

Another tip for cleaning your diffuser: Check in your attic to see if all of the seams are taped up. If you can see daylight coming through the tubing, you will need to tape it up. Usually this is how bugs find their way inside the tubing to where you have to clean the diffuser.

I am against the "window" type skylights. I have hundreds that have leaked. That being said I have 5 from SunCowboy and they are fantastic! Guests think they are lights, they don't leak and with the large volume of air in the tube, are very energy efficient. I siliconed the diffuser on, then screwed on the trim ring which made all the difference for Minnesota's winter and condensation.

ICF Construction,

Sounds like you have had some bad expeirences with traditional skylights.

However, I would say that if there have been hundreds that have leaked it will most likely be the person installing them. 99% of the time it is wrong installation that causes a rough opening leak. Rarely the actual skylight product will fail, but older skylights can need repairs down the road just like any window. If all skylights leak, the skylight manufacturers would be out of business.

Skylights have got a black eye and for undo reasons.
People do some crazy things on the roof around skylights ie: make their own flashing, use the wrong flashing for the roofing material, install upside down, use under pitch, use NP1 or some roofing cement around the flashing causing water damming.

If you use a reputable skylight manufacturer with an engineered flashing system along with ice and water shield or some form of roofing underlayment you won't have an issue.
On top of that, if you happen to have a defective skylight a reputable manufacturer will have a warranty covering a homeowner against leaks.
This warranty is null and void if the skylight is installed wrong.

Tubular skylights are viewed differently because the flashing doesn't freak the installer out. The flashing is very simple and is done exactly like an attic vent is done.
Not a difficult install on the roof thus a tubular skylight was designed for a DIY to install.

I will be honest, I have never heard of a Sun Cowboy tubular skylight.
The most common manufacturers are VELUX, Solatube, ODL, Sun Tek, Sun Dome, Sun Pipe, Solar Industries, and Natural Light. I would like to think Sun Cowboy is selling one of these tubes.
If they make their own, I can't comment on them because I have never seen one.

Sun cowboy is a vendor. I dodn't know the make she sells as there were not names on them but Kathy gave me a great price and service.
I like the units better than any I have installed before. I put 2 -18" ones in my new house for the 1000 sqft great room and they light the whole room up substancially.
Her flanges are heavy duty as are the collectors. The best part are her diffusers.
My tubes are 8'.

I have been a construction consultant for 18 years and inspected thousands of roofs. The only thing that leaked more often than traditional skylights was chimneys, and that is only because more houses have chimneys. It is unusual not to see a water stain by a skylight, if not from a leak, condensation. While I agree they were often cheap skylights and/or improperly installed, the installation is less forgiving than the tube type

The tube type I love. I researched it extensively 5 years ago before buying the ones from SunCowboy, can't recommend them enough.

Raider Bill,

Thanks for the information.


ICF Construction,

You have extensive construction background and understand roof penetrations. Yes, Chimneys are also notorious for leaks as well. Chimneys and skylights are flashed in very similar manners. The chimney gets a pass for the most part because it is sometimes hard to see the leak inside the house. A skylight you know where the leak is coming from.

You brought up a good point about condensation. Some leaks can be attributed to condensation.

And yes, a tubular skylight is less likely to leak. However, proper installation is required with a tubular skylight as well.

The installation is the key!

I would tell people to look for skylight manufacturers with turnkey installers if you do not want to do the installation yourself. Many times these installers will provide a installation warranty on top of the product warranty.

Well, I called Kathy at the place in OK that someone above suggested. I called several times, never a return phone call. I ended up ordering (4) 13" SunDomes and (2) 10" SunDomes for the manufacturer in FL, Don the owner was very helpful. www.Sun-Dome.com
The workers are installing them as I type.
I talked to Velux and for their dome lights they do not have a metal roof gasket kit. I have a metal roof, only thing that makes sense from stand point of $ and strength in a hurricane zone.

So I wil have 6 lights all together. I'd have used more if we were not so over budget on this project. You can see the sun dome lights after installation at http://www.concretecottage.com

I was wondering if any of you folks consider the energy efficiency of either skylights or the tube light? Does anyone have any good comparisons on energy efficiency? I'm building a ICF home and have an 2 inside bathroom with no window excess. But I'm reluctant to cut a hole in the roof for a skylight or tubelight, seems I'd lose more energy than the light gain, any thoughts!

IndianaFred,

Argon Insulated Glass skylights have low e2 coatings just like any verticle window has. Tubular skylights with the diffused light generate less heat into a home than a 60 watt light bulb will generate!
Daylighting has a better efficacy than any other lighting source.
Efficacy= lumens/watt.
I would make sure the skylght has a wood frame for better UValues and that the skylights framing and drywall properly insulated in the attic.
With that said you are introducing no more heat with a skylight than you would with a window.

The benefit to a skylight is that you receive approx 30% more light from a skylight than a window of the same glazing area.

Most skylights are Energy Star Rated and you can find UValues and SHGC for every manufactuer that has had their products tested at. www.nfrc.org.
The National Fenestration Ratings Council. All window, door, skylights companies test their products with the NFRC.