Return to the Renewable Energy Forum | Post a Follow-Up

 o
solar tube skylight

Posted by ryanaidan (My Page) on
Mon, Jun 14, 04 at 23:49

Does anyone out there have a solar tube sky light and/or a solar attic fan. We are builing a new home and I would like to incorporate these if they are as good as they sound. What brands, sizes, how compares to electric? I would build as much of a green house as possible if we could afford it. Also if I could sway my husband to my opinions. I feel like we environmentalists are far a few between.
Thanks for any help


Follow-Up Postings:

 o
RE: solar tube skylight

.

I've had a Solatube brand tube light now for 3 years . . . VERY happy with it; does a nice job of lighting up an otherwise dreary room. I have two extensions on mine ( distance from roof to ceiling of room is ~ 6 feet ) and there's LOTS of light from it; of good spectrum; but NO heat gain. I have the 14" size . . . . there are other sizes . . other brands too but I cannot speak of any others.

As far as a solar attic fan is concerned; if you are building new then why not build OUT the need for one. I can see a need for one in an existing structure that was not properly built / vented; but I'd simply avoid using one alltogether in new construction . . . .

Consider metal roofing . . . I don't necessarily mean standing seam stuff that can cost big bucks . . . there are a lot of much more reasonably priced kinds out there in all colors / profiles that can really add to the look of a place . . in addition to making a damn good roof. They don't require sheathing / plywood; only a grid of 2 x 4's; and can literally outlast YOU . . . and when they finally have seen their day; are easily recyclable. Using loose blown cellulose between attic and living space will reduce noise from rain to an actually very pleasant sound . .. easy to fall asleep to. Compare that against shingle roof which is the norm lots of places and certainly has a lifetime and is nowhere near as recyclable if at all; as a metal roof. Besides; a metal roof holds FAR less heat as there is very little mass to it . . will help with attic cooling which you seem to have concerns with . . . .

Bob


 o
RE: solar tube skylight

I had two 10" solatubes in my last house. Was very happy with them. The light wasn't that dramatic because of 10' ceilings, but was alot better than the cave of a hallway that was there. In our new house I had the same thing installed from skylights-to-go. We saw them at a home improvement show last winter. Our ceilings are 8' now and WOW! what a difference! For the first month I kept thinking someone had left the hall light on.
Neither brands have leaked or transfered heat to the inside. For the money I think they're great. The only reason we went with skylights-to-go was a better warranty.


 o
RE: solar tube skylight

Solatube has gotten an energy star rating. See solatube website for more details


 o
RE: solar tube skylight

We have installed 8 sun tubes in our new house, 7 10" in the house and 1 14" in the garage. We love them so far they have made a huge difference in our interior rooms. Several of the tubes have 9' or more of extensions and still give off a lot of light.

These two photos I took last week in our interior bathroom with the door closed and the flash off.

This photo was taken of our dining room before the sun tubes.

After....


 o
RE: solar tube skylight

I think they are a good idea.
Several of my clients have installed
them and all are very pleased.
Ceiling height and placement make all
the difference as does install.
I do prefer the Solatubes personally,
it seems sturdier than some of the
other brands I have seen.


 o
RE: solar tube skylight

I had two in my bathroom in my previous house. They were wonderful! Just like the previous posters have said, there was absolutely no heat gain. I loved them.

With regard to the attic fans, I didn't have a solar one. I had an electric one, but exchanged it for the one that looks like a mushroom (you know, the one that does not use ANY electricity, 12V or not.) I just loved that attic ventilator as well.


 o
RE: solar tube skylight

Could a solar tube be installed in an earth-bermed house if a passageway was built through the ground for it?


 o
RE: solar tube skylight

If a properly sealed and waterproofed passageway was built I don't see why you couldn't. You probaly would want to insulate it also so you don't get condensation.


 o
RE: solar tube skylight

Has anyone seen any R or U value ratings for the solar tubes? It would be very interesting to do the heat loss calculations against a high R value attic insulation (65+).


 o
RE: solar tube skylight

.

I have not seen any R / U values; or any heat loss calculations for Solatube. However; since I own one I can give a little insight perhaps; but no "numbers".

At least on the Solatube; there is a very good gasket where the diffuser meets the tube; at the ceiling. In my particular case, I have two "extensions" for about 6 feet from finished inside ceiling to roof. I used two layers of "Reflectix" insulation around the tube all the way between finished ceiling and the roof. The top of the Solatube dome is fully sealed against rain / snow; but there is a loose gasket to allow slow ventilation . .. lest condensation would form if the thing were totally sealed. So, at least in my mind the method of heat loss will simply be convective through the column of stagnant air in the tube itself. I was ( happily ) surprised that there has never been any condensation form in the Solatube; I attribute that to a good seal on the inside and small but definite ventilation of the air in the tube to the outdoors to vent any that might want to form.

I know; doesn't answer your question really; but at least I think offers some insight. I have 18" blown cellulose in my attic area; this place is very tight / efficient . . . I noticed no change after installing the Solatube . .. .

Bob


 o
RE: solar tube skylight

I don't know which brand our builder installed last week, but the kitchen tube is bothersome, because the glare is so strong. I don't notice it in the bathrooms, because the ceiling is not visible from a distance. I really regret putting it in my kitchen. I should have changed the roof overhang during the framing stage, so there would be more light in the kitchen.


 o
RE: solar tube skylight

It is hard to find data on their R or U-value. The home energy raters use a U value of 0.85 (which equals an R of 1.2). So they are basically a thermal hole in your roof.

see
the link below, near the bottom of page 4.

Niels

Here is a link that might be useful: rem rate estimate on solar tube U-value


 o
RE: solar tube skylight

.

I'll agree they're not better than insulation; but I'm not sure I buy the .85 rating either; or perhaps how it was derived.

My Solatube has a tight gasket at the dome end; and a very tight gasket at the ceiling. In my particular case; that makes a long tube ~ 12' long . . . of trapped air. While there may be some convection circulation going on there, I don't believe the heat losses are that great. I've never noticed a hint of any coolness coming from it . . it's directly above my chair at the dinner table . . and it would have been noticed if there was any. I've also noticed that snow sits on it in the winter . . . which is another indicator to me that there is little heat loss . . if there was, the snow would melt off of it.

Look at the R-values of Reflectix . . different in different directions . . vertical install, horizontal install; flow upwards, downwards . . . all different . . some pretty high, some pretty low. Again; I believe the methodology of figuring R-values is not perfect . . and in some cases; probably really misses the mark. Besides; R-value is a measure of a very specific thing under lab circumstances . . which are not reality. I live in a log home, which many attribute an R-value of "R-crap". No insulation, no R-value. Reality is that wood IS an insulator, under a microscope it is largely trapped air spaces. Also not figured into R-value of logs is the thermal mass effect. The combination works VERY well . . . and I ( and lots of others ) have the heating bills to prove it.

R-value is a very specific measure of a very specific thing, under lab conditions. Real world can be something very different . . . .

Bob


 o
RE: solar tube skylight

Bob

You are right about r-value being a laboratory measurement. And real world being very different from the lab.

And I agree with you the tube light are not leaky if installed correctly. But the R-value isn't about being leaky or not - it measures thermal conductivity.

R-value (ie., U-values) It seems to work for other types of windows.

Regardless, a solar tube would need to have more than seventeen times its 'measured' r-value to get to a decent ceiling r-value of 21.

Niels


 o
RE: solar tube skylight

.

Leaking is a direct loss . . yes; it is more about thermal conductivity as you say . . if you've eliminated any direct leaks.

Look at any insulation . . . f'glas, cellulose, rigid or spray foam(s) etc . . . and they all share one thing in common: Trapped dead air spaces. That is what in fact gives them their R-value.

In the case of a properly installed Solatube ( or similar ) there is one big trapped air space. Makes it insulation by virtue of having that. The one difference is that it's open and large enough so that thermal circulation / convection CAN occur . . and I'm sure does to some extent. That limits it's thermal performance vs having many, smaller trapped air spaces.

Once again; it's NOT gonna give you R-value anything NEAR good attic or wall insulation values; but again no window of any kind does. By virtue of the fact that snow sits on it and doesn't melt; I can't assign an R-value to it . . but if it was as bad as you suggest; there would NOT be snow sitting on it.

In the bigger picture though; when you figure how much of your attic insulation is "impinged" by having a Solatube or such; in term of area and thermal losses; I'll guess that all but the very best insulation jobs have more inadvertent leakage than a Solatube or two has . . . .

Bob


 o
Question about Solar Tube Condensation

Hello,
Last year we had our roof redone and had 6 solar lights installed at that time. They've been great except that today we noticed water droplets on the lens and opened up the covers to find excessive water condensation on the top of domes. We are pretty sure it is condensation but are concerned how this will affect the tubing, mold issues etc. We live in Idaho so I don't believe this was an issue until the weather started to get cold.
Any Advice?
Sandy in Idaho


 o
RE: solar tube skylight

What does a 10" solatube cost typically for new construction?


 o
RE: solar tube skylight

We have 2 solatubes installed and have had no condensation till after we had a cold snap of way below zero temps. I noticed some dripping onto the lens and when we removed it there was some dripping inside the tube. We had had the lens off earlier this fall and we thought maybe we didn't have a good seal between the ceiling and the cover. Would this be the problem and how do we fix this? Any ideas?


 o
RE: solar tube skylight

We live in northern Wyoming at 5100 ft. All 7 of our ODL skylights are frosty inside and dripping condensation. If you read the specs carefully they say to insulate the tube as it goes through the attic in northern climates.

I have had Solatubes; was not impressed for the price and the plastic lenses at the ceiling yellowed considerably.

I researched heavily and found the ODL's. They have a glass lenses at the ceiling and are considerably cheaper than the Solatube. Side by side it's difficult to tell any difference.

Although I purchased my first ODL's online all the ones for this house were purchased at Home Depot.

We are going to have all the skylights tubes insulated with sprayed on foam insulation. For now we have towels inside the tube to catch any condensation.


 o
RE: solar tube skylight

I purchased eight 21" commercial Solatubes for a commercial client and when the materials arrived, boy was my client pissed. I think the total cost of materials (not including installation) was around 11,000.00 dollars. YES, ELEVEN THOUSAND DOLLAR$$$$$$$$

They advertise this great new technology, MY BUTT!!! Its clear plastic domes and super thin reflective metal sheeting and thats it. A good idea but by no means is this any advanced technology. For them to even state that is laughable.

The tube metal needs to be assembled onsite (with screws and tape) and is so thin (easily dented and damaged) that I dont recommend installing the tubes until all other trades are done. The lenses for interior ceiling are also cheap plastic. The only quality material was the roof flashing.

For the eleven grand I guess their costs were only about $500.00 in materials AT THE MOST. There are overcharging massively for the amount of money it costs them to produce these skylights. I wager they spend more on packaging and shipping then they do in manufacturing.

The warranties are good but who gives a hoot if the warranties far outlive the product. They can afford to give such high warranties as they make so much profit on the sale and count on people not coming back to them four or five years down the road.

I see these domes and ceiling lenses yellowing a good bit and in a short amount of time cutting down on the light transmission. They advertise a 95% light transmission from the roof to the interior lens and my light meter only showed around a 60% just out of the box. Not bad but not worth the money for such a low quality product.

Im sure Ill get a call back to insulate the tubes as condensation is an issue running through the confined space. The true value of this product is worth about a third of what they are selling it for. I also see the life expectancy of these skylights to be about a third of traditional skylights before maintenance and parts replacement is necessary.

MAJOR RIPOFF - NOT RECOMMENDED!!!


 o
RE: solar tube skylight

I have two ODL skylights in my kitchen. I have the severe weather ones that pass Miami Dade MPH codes. I am planning a new addition and adding five more skylights. I have no issues, and love the light bulb feature for use at night. Check out Home Depot prices online, make sure and order the extension tube.


 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!


Return to the Renewable Energy Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.


Learn more about in-text links on this page here