Comments on: The Benefits and Drawbacks of Skylights https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/ Building science knowledge, HVAC design, & fun Tue, 14 Mar 2023 15:13:41 +0000 hourly 1 https://wordpress.org/?v=6.6.2 By: Allison Bailes https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9080 Thu, 14 Jan 2016 01:29:17 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9080 In reply to Avery Colter.

Thanks for sharing your
Thanks for sharing your experience, Avery. That’s good to know.

]]> By: Allison Bailes https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9084 Thu, 14 Jan 2016 01:26:15 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9084 In reply to Steve Vollstedt.

Steve, we used the 99% and 1%
Steve, we used the 99% and 1% outdoor design temperatures for the locations we chose, which were Pensacola and Detroit. We used the standard indoor design temperatures of 70° F and 75° F, as recommended in Manual J.

For more about design temperatures, see:

We Are the 99% — Design Temperatures & Oversized HVAC Systems

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/53306/We-Are-the-99-Design-Temperatures-Oversized-HVAC-Systems

]]> By: Allison Bailes https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9082 Thu, 14 Jan 2016 01:23:10 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9082 In reply to Ryan Shanahan.

I’m going to be giving them a
I’m going to be giving them a call soon before I write an article about their products. Stay tuned.

]]> By: Steve Vollstedt https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9083 Thu, 14 Jan 2016 00:32:02 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9083 Allison – For your btu/sqft
Allison – For your btu/sqft/hr calculations, how did you come up with the outdoor temperature in the summer & winter, and what did you use for indoor temperatures? I am assuming that for the summer you used the average high temperature for the 2 or 3 hottest summer months and similar for the winter season, right?

]]> By: w d https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9997 Wed, 13 Jan 2016 23:55:15 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9997 Allison,
Allison,

Nice summary on the +/- of skylights. I especially appreciate the heat gain data.

Our house has two skylights. I’d prefer zero. We’ve found a way to live with our skylights. The idea is to accept the solar heat gain in winter while blocking it in summer. First, we created another glass pane by custom fitting an acrylic sheet on the interior in the skylight well. Next, we installed solar grates on the exterior during summers (a/c season). The grates are in storage during winter (heating season) and thus the solar gain is maximized. As far as aesthetics, the lighting benefit from skylights is available year around. When the grates are in place, indirect light is passed while direct light is blocked. Hence, no “too bright” effects.

We also use solar grates on our windows for similar benefits. The reduction in electricity for air conditioning is substantial.

]]> By: Ryan Shanahan https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9081 Wed, 13 Jan 2016 23:23:08 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9081 If you can get a good thermal
If you can get a good thermal seal at the bottom lense of the solatube (on the flat ceiling plane) in theory it negates the need for insulation on the tube. I’ve always been curious if the NFRC ratings on solatube are for the top lense or the bottom. Does anyone on here know? Curious…

]]> By: Avery Colter https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9079 Wed, 13 Jan 2016 22:49:44 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9079 In reply to Tyler Kime.

Maybe it’s different and
Maybe it’s different and better now, one would hope. I bought a fixer in 2001 and thought a couple of skytubes would be a good choice, one in the bedroom and one in the living room. They were simple ones, with an inline socket for a light bulb. I eventually put in LED PAR38 so the light would be downward and not have half the light going upward out of the roof. The seals seemed good enough at the roof, as there was never any issue with water. There was absolutely no insulation however on the tube itself. The tube came in two pieces which had gaps that I had to try to tape together, but that wasn’t a perfect fix. As a result, bugs would get in the tube, and I had to take off the diffuser periodically to clean it. The diffuser was one of the most annoying things, very difficult to twist on the right way. I had to screw wall mirror brackets into the ceiling to keep one of them on in the bedroom, and in the living room one, having actually lost the diffuser, I ended up taping Saran Wrap over it. The funny part is the taped-on Saran Wrap turned out to be a better air barrier than the diffuser, and I have the blower door readings from the county weatherization program to prove it! Have not put any sky tubes in the new house. My problem is the opposite of one of the posters: my wife would kill me if I made mention of them after the past experience. And I myself, if I did any such thing again, it would need to be a high-end low-e model with a day dimmer.

]]> By: Armando Cobo https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9076 Wed, 13 Jan 2016 22:12:04 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9076 In reply to Allison Bailes.

I don’t want to
I don’t want to sound like a Velux dealer, but they have great Skylights and Sun Tunnels. They are not cheap, but they are way above the competition in performance. Check them out.
For the Skylights, U=.42-.27 & SHGC=.23-.12 depending on model and shades. For Sun Tunnels, U=.51-.16, again depending on model. The house orientation is more important than the roof orientation, therefore if I have a way to block some of the direct sun, fine, if not, we do have a small penalty. Do have in mind that the Skylight/Sun Tunnel area is typically around 1% or less.

]]> By: Allison Bailes https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9078 Wed, 13 Jan 2016 20:57:09 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9078 In reply to Tyler Kime.

The Solatube (solatube.com)
The Solatube (solatube.com) is a good alternative. Their specifications for U-value and SHGC are mostly close to what’s allowed by code, but they do have one model with an SHGC = 0.16. As far as I can tell, they don’t provide insulation for the tube. Probably the best way to insulate it would be with spray foam.

]]> By: Allison Bailes https://www.energyvanguard.com/blog/the-benefits-and-drawbacks-of-skylights/#comment-9075 Wed, 13 Jan 2016 20:47:44 +0000 http://energyvanguard.flywheelsites.com/?blog_post=the-benefits-and-drawbacks-of-skylights#comment-9075 In reply to Armando Cobo.

Armando, if you can design
Armando, if you can design and spec bonus rooms with skylights and they have no problems, more power to you. That’s a really difficult task, especially in Texas. What U-values and SHGCs are you using for skylights? What roof orientations do you install them on? Do you use any kind of shading?

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