Solar Tube Lights: A Great Way To Bring Natural Light into a Windowless Room!

Solar tube light diffuser

One of two solar tube in kids’ bonus room.

By Trish Holder

“Is that a solar tube light or have tiny flying saucers landed on your house?”

I’m sure our neighbors have wondered this – at least if they get a view of the backside of our roof after dark.

We have five solar tube lights and at nighttime the exterior domes reflect the light from inside our home into the darkness. That’s not their purpose, just a quirky little “sidelight” of solar tube lights. It’s just a little curious looking, enough to make you say, “Huh, wonder what that is?” as you drive by at night.

Bath In Sunlight But Not the UV!
Despite the suggestion of itty-bitty extraterrestrials at night, I like my solar tube lights a lot. It’s a great way to bring natural light into a room with no windows, plus you avoid a lifetime of electrical cost.

We installed two solar tubes in an upstairs bonus room that has no windows and three in an upstairs Jack-n-Jill bathroom. These are all kids’ spaces, so I like the fact that I’m bringing in some healthy, natural light. I also like the thought of my kids getting a little shot of sunshine when they shower in the morning. No worries about harmful UV though – these lights block out 100% of UVB and UVC light and almost all UVA. And, unlike skylights, there is negligible heat gain with a solar tube light.

On partly to mostly sunny days these lights will fill a room with abundant white light. Trust me – you won’t be reaching for the light switch. On rainy or overcast days, you still get lots of light, but it tends to be a little bluish. You can counteract this with the light kits that come with some solar tube lights, or additional room lighting.

Solar tube light installation

Light from the outside is reflected down the aluminum tube.

They Go Anywhere
Solar tube lights can be installed in any room of the house – as long as you have a closet or wall cavity to hide the tube. All of ours are upstairs, so they are hidden away in the attic.

The rooftop dome (flying saucer) collects the light and redirects it into the aluminum tube, which is extremely reflective. Sunlight bounces its way down the tube and into the room via a light-diffusing fixture.

I’ve enjoyed having these in my home and I think they are a great (and smart) addition to any interior bathroom, laundry, or utility that lacks natural light. Sunlight is also a natural mold killer – not that solar tubes are the ticket to a mildew-free bathroom. If only.

Installers Can Be Hard to Find
The one negative thing I have to say about my own solar tube lighting experience is that it can be difficult to find someone to install them. The manufacturers have installing distributors, but they can be few and far between in certain areas of the country. Some say it is a do-it-yourself project, but keep in mind, this is a hole in your roof. Besides the safety issues climbing on top of the roof, solar tube lights have been known to leak if they aren’t properly installed or sealed. An HVAC guy (with no experience) installed ours. So far, so good.

Although we haven’t had problems with moisture, these things do attract bugs and I’ve noticed recently that over 2 ½ years we have acquired a little collection of winged corpses. Not a big deal really – since you can take off the diffuser from inside the room and clean them out. It probably takes 60 seconds; we just haven’t gotten around to it.

Prices of solar tube lights vary depending on how long the tube has to be. The tubes can be installed to twist and turn every which to get the light where it needs to be, but this length and multiple angled fittings will drive the price up. Expect to pay at least $250.00 plus the cost of installation–little green men not included.

8 Responses »

  1. I think the drawback is that they are a big heatsink into your home.
    You would not to install too many.

    • Actually, that’s not the case. Solar tube lighting — at least the brand I used — have insignificant heat gain, so air conditioning or heating are not affected. Electric lights actually add more heat to a room. The solar tube lights made by the manufacturer I cohost have a Solar Heat Gain Coefficient (SHGC) maxima of 0.30.

      • Keep in mind that unlike a wall window, in most cases that penetration is going to get constant day time heating. After recording a midday temperature of 120 degrees in May at a solar tube (not the brand) opening, we stopped recommending them, even though they do a great job of day lighting.

  2. It is a smart idea, not so new, but surely ecological.
    I live in Italy and unfortunately here we live in apartment and not house, so it become difficult to install a solar tube in a condominium.
    But this article stimulated my interest and I decided to take more info locally.

  3. I’ve had two sunpipes in my Victorian home filling my upper landing (and the hall below) with light for about 10 years now. One is fed from a west-sloping roof and the other from the east-sloping. Even in the winter in UK, we rarely put on either the hall or landing lights during the day (they would otherwise be on as the space is internal) and we are often “moonlit” on clear nights. I’ve never noticed an issue with heat loss (no thank you!) or heat gain (yes please!) in the UK – the acrylic diffusers are quite substantial and seem to fit well – the upper landing never feels “different” to the rest of the house. I generally get up and clean the insects out about once a year, and would definitely use them again in “windowless” spaces.

  4. We had a solar tube installed by a local professional in our main hall bathroom. This was our second summer with the unit installed and we have not experienced any solar heat gain from it. The dome is on a South facing slope and we are in the Mid-Atlantic region. During full moon cycles we do find that we have to close the bathroom door or middle of the night seems like any sunny afternoon in there LOL! We are thinking of adding another unit for the stairs that lead to the basement. It would keep me from turning on the light for those trips to the laundry room.

  5. This is an interesting concept but, as with some people above me, the first thing that came to mind was the heat gain/sink. Maybe this could be mitigated by filling the tube with an inert gas (like Xenon or Argon) like they do in some multi-paned windows? Or maybe even adding a transparent heat-diffusive pane. I suppose this also depends on the location in the summer in a desert like Israel, this might be make a difference.

Leave a Response