Historic windows present challenges when it comes to mitigating the effects of UV and thermal transfer. Providing both UV and thermal barriers for historic windows is often accomplished via some ancillary attachment. Here are a few examples, with associated pros and cons:

 

Insulated roller shades
- Can protect against UV while still allowing natural ventilation

- Can sometimes be concealed when not drawn (doesn't always interfere with historic import)
- Not the best possbile air or thermal barrier - e.g., in winter, can still allow for condensation to form on glass

 

Sealed quilt or roman shade

- This refers to a heavier, well insulated interior shade mounted on tracks that forms a reasonably good air seal around the window
- A well known brand is  Window Quilt (claimed R value from 4.6 to 7.1)

- Bulky, and may not appeal to some; may detract from historic import
- Better air/termal barrier than a roller shad, but might be less than adequate if both UV protection and natural ventilation are desired in summer

 

Exterior storm window
- Might help to further mitigate any air/moisture infiltration issues
- Newer ones are designed to be nearly invisible - don't detract from historic import
- Can be onerous to remove every spring and replace every fall

 

Use of exterior awnings, overhangs, or plantings (transpiration, shade)
- Natural, passive
- Can help extend the effects of existing heating/cooling mechanisms

 

In general, what approaches have any of you attempted, and what sort of results have you achieved? What seems to be a preferred strategy (or combination of strategies), or potential best practice solution to this problem?

Tags: Barrier, Preservation, Thermal, Transfer, UV, Windows

Views: 2583

Replies to This Discussion

I did an audit recently for a lady that does custom window treatments.  Curtains, blinds, drapes.  She discussed the Hunter Douglas line of blinds that she handles.  Interesting stuff.  Some have an Energy Star Label, and make claims of an R-Value.

My personal preference is for Solar control outside the envelope.  My professional guidance is that people have to do something and an effective interior solar control they will have installed and use is better than an approach that is not used or even installed.

Thanks very much Bill, for describing your exterior storm solution (sorry I'd neglected to reply when you first posted this a year ago). Question I have is: Do you drill weep holes in the bottom furring strip supporting the exterior storm? And if so, do you just leave them open or install small plugs and open or close when necessary? Thanks Bill!

Hi John,

I don't internet much either.

I install the bottom furring strip in pieces and usually have enough left over from the other 3 sides to piece together the bottom. This is the only time I use that funky PVC wood. I keep the holes small, so I feel like it is OK to leave them open all the time. I haven't had any call backs yet, though sometimes I wonder if it is wise to claim that exterior storms will eliminate interior condensation problems.

Thank you so much for starting this group, my overarching passion is to merge the craftsmanship still intact in many older buildings with technology and building science.

John,

I'd also like to add to your "laundry list" a product that I have had some experience/frustration with, but ultimately hope for. http://www.solarizewindowinsulators.com/ It's dang intriguing if nothing else. I'd love to hear of other folks' experiences with the Inflector product.

It's basically a reversable interior storm window-- radiant barrier on one side, solar absorber on the other. It's brilliant in concept but I can't help thinking it looks like an overpriced NASA-designed trash bag.

My mother in law had three skylights facing south in her 1890's home-office. She loved the light, hated the heat, and wanted to save energy in the winter too. (Wow, that's a lot to ask of a hole in your ceiling). So I installed three Inflector panels. She hated the way they looked and took them out before I ever got any good data on their performance. I'm a little suspicious of their own data claims, as the product is outside the realm of a SHGC-defined window/ storm tests.

Hi Chris. Thanks very much for added this to the forum. The information and test data they provide seems rather substantial. But I agree with you -- it'd be great to hear from any one else who's installed these or a similar reflective barrier, and had had a chance to observe the results. Agree that it at least sounds good.

Here is my list of other professionally made interior air panels and interior "storms":

Downeast Interior Storms
Rendon Sabina
47 Chase Farm Rd.
Newcastle, Maine 04553
207.380.7680
rendon at downeastinteriorstorms dot com
http://www.downeastinteriorstorms.com/

Eugene Mueller
Energy Wise Mfg
563.542.2134
http://www.energywisemfg.com/insiders.html

Advance Energy Panels (AEP)
James Levine
(800) 819-9463
http://www.windotherm.com/index.htm
AEP now has kits to make panels:
http://www.advancedenergypanels.com/department/kits-3.cfm?killnav=1

R-Plus Window Insulators
http://www.proactiveenergyconcepts.com/proof.html

Indows
http://www.indowwindows.com/

Hi John,

Thanks very much for contributing all this information. It looks like a few of the links were broken when I tried them. In particular, the "Buy AEP -Kit" button is broken on both the Windo-Therm and AEP home pages and I couldn't find any other obvious links that worked. On the other hand, if you Google "Advanced Energy Panels Kit", quite a number of third parties who resell them are listed. Also, the Window-Therm and AEP home pages (one in the same) are either http://www.windotherm.com/ or http://www.advancedenergypanels.com/, respectively, while the R-Plus Window Insulators home page now seems to be http://rpluswindows.com/

There's a company right in Boston that makes a very nice aluminum/low-e glass spring tension interior storm that I've seen a few times, who's name just keeps on eluding me. I need to sift though some paper files to find it (never an exciting prospect), but when I do, I'll post here as well.

Thanks again, John, and hope all is going well by you!

~John

Both interior air panels and exterior storms are now included in the National Window Preservation Standards:

Air panels:

http://ptnresource.org/WPSC_forum/viewtopic.php?f=19&t=76

Storms:

http://ptnresource.org/WPSC_forum/viewtopic.php?f=19&t=184

John

www.HistoricHomeWorks.com

This is great, John. Thanks very much for posting these links here...

~John

Larson is a manufacturer with national distribution of interior and exterior storm windows. See:  http://www.larsondoors.com/storm_windows/ for more information.

It is indeed a challenge to retain those historic windows, etc. but I think any contractor can remodel it maybe by adding blinds, etc. nothing is impossible now.

RSS

Discussion Forum

Two Part Epoxy and Repair of Structural Wood

Started by John Poole. Last reply by Patrick Michael Hayes Oct 14, 2016. 11 Replies

Historic Windows: UV and Thermal Transfer

Started by John Poole. Last reply by Shade Structures Jan 31, 2013. 23 Replies

Historical Window Energy Efficiency Upgrade Standards?

Started by David Clark. Last reply by Robert R Gilbert Jul 13, 2011. 11 Replies

Historic Windows: Air/Moisture Infiltration

Started by John Poole. Last reply by Bill Bradbury Jul 10, 2011. 1 Reply

Spanish Style Architecture Wall Construction Details

Started by John Nicholas. Last reply by Bill Bradbury Jun 29, 2011. 2 Replies

Latest Activity

Franco Oyuela commented on David Byrnes's video
Thumbnail

Why One Room Is Hotter Than Others

"If the temperature difference between your bedroom and your living room feels like walking from a…"
yesterday
Franco Oyuela replied to Jan Green's discussion Mini split installation location
"First: Mini split are a great option. Second:vI agree with David that installing on the south…"
yesterday
Pearl Home Certification's blog post was featured
yesterday
John White replied to Frank Spevak's discussion Think of the house as a really big duct
"Thanks for sharing this helpful information. Want to read more on duct cleaning pros and cons.…"
yesterday
Jan Green replied to Jan Green's discussion Mini split installation location
"Thank you, thank you!  I appreciate your insights.  I agree with the idea that installing…"
Thursday
David Butler replied to Jan Green's discussion Mini split installation location
"Hi Jan, in a room like that with a relatively balanced aspect ratio, flat ceiling and not much…"
Thursday
Rick Blair joined Kyle Brown's group
Thumbnail

Wrightsoft - Manual J / Manual D

If you use Wrightsoft to calculate loads or design ducts, you likely have questions.  Get answers…See More
Thursday
Jan Green replied to Jan Green's discussion Mini split installation location
"This is a very rough diagram of the detached casita.  There are currently no windows in this…"
Thursday
Sean Wiens liked Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
Thursday
Andrea Simmonsen liked David Byrnes's video
Thursday
Beverly Lerch replied to Beverly Lerch's discussion Mini split air conditioners and ceiling fans
"Thanks.  A very reasonable, practical answer.  We have done our experimenting and ceiling…"
Thursday
Pearl Home Certification posted a blog post
Thursday
John Nicholas replied to Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
"Jerry, ;Have you opened the cathedral ceiling?  "
Thursday
Blake Reid replied to Beverly Lerch's discussion Mini split air conditioners and ceiling fans
"Good opinions in these replies!  I'll just add a few: * Experiment.  It's your…"
Wednesday
John White replied to Jerry Needham's discussion Condensation on ceiling and walls of master bedroom
"Condensation on ceiling occurs when the attic space above is poorly ventilated or insulated. The…"
Wednesday
Joshua P Murphy is now a member of Home Energy Pros Forum
Tuesday
Franco Oyuela replied to Frank Spevak's discussion Think of the house as a really big duct
"THANKS for the information. Ducted mini splits offer hidden benefits."
Tuesday
Franco Oyuela replied to Wayne Melancon's discussion What's the Most Profitable HVAC Job for Your Company?
"Get into commercial, it's more money!"
Tuesday
David Byrnes's video was featured

Why One Room Is Hotter Than Others

Ever wonder if your air conditioner is working right because one room never gets a cool or warm as others? Do you need a bigger air conditioner to fix a room...
Tuesday
Profile IconEric MacCallum, Adam Morgan and Caolan Hutchens joined Home Energy Pros Forum
Monday

Photos

  • Add Photos
  • View All

© 2018   Created by Home Performance Coalition (HPC)   Powered by

Badges  |  Report an Issue  |  Terms of Service