Image Credit: Alex Wilson
More Energy Solutions
Despite the chilly (seasonable) weather, work is progressing on the renovation/rebuild of our house in Dummerston. Last week, the three exterior doors were installed. Which brings me to one of my pet peeves: the lack of really good choices for highly energy-efficient exterior doors.
We ended up with a solution that I think will be okay, but there is a huge void in the world of truly high-performance doors. Here, I’ll describe the three doors we put in. I hope you can put up with my whining.
The front door
The purpose of front doors, I’m told, is to look nice. But I also wanted a front entrance door that would remain stable and airtight over many years or service and that would provide reasonable insulating value. Oh, and I didn’t want to spend more than about $2,000 for it. That proved a challenge.
I would have loved to install one of the gorgeous custom entrance doors made by Steve Benson’s company, J.S. Benson Woodworking, in Brattleboro. They are custom-fabricated of durable and highly stable triple-laminated mahogany (sustainably produced wood certified by the Forest Stewardship Council is available), but as solid wood, there is very little insulating value: maybe R-3 for a 2-3/4”-thick door.
For Benson doors with lites, the energy performance gets a little better, because Steve has access to super-high-performance glass from Alpen Windows in Colorado. Those lites can provide an insulating value of R-5 or even more — significantly higher than the solid door.
Steve’s beautiful doors have one other drawback: they cost an arm and a leg, starting at about $5,000. A little rich for our budget.
A high-end fiberglass entrance door
When I was researching doors for the house at Leader Home Center, I came across a Jeld-Wen door made of fiberglass but with a knotty-alder grain that looks remarkably like real wood — and I say that as someone who pays close attention to wood and can readily distinguish most species based on the grain. One could easily be fooled into thinking this door was real alder!
This door looked good. It was solidly built, yet it had a polyurethane insulation core, significantly boosting its R-value. I had already researched fiberglass vs. steel, and found that most energy experts preferred the former, even though magnetic weatherstripping can be used with steel.
“That’s the one I’d like,” I told Russ Chapman at Leader, referring to the knotty-alder floor sample. (Russ had been incredibly patient with me as I picked his brain for energy-performance information.) He said he’d price it out and get back to me.
Oops. It turned out that Jeld-Wenn had discontinued that model as a stock item; that particular door had been on display for three years. A similar door was still available, but it’s now a fully custom, hand-made option, and instead of costing around $2,000, it was going to cost something like $10,000!
“So what about buying this display model,” I asked Russ? It had a few dings, but would suffice. He figured out a nice price for it (the floor model wasn’t doing them much good, since that door wasn’t really available anymore as a reasonably affordable product).
Because we couldn’t get a matching side-lite in the same knotty-alder wood, we had the door hung with a totally different, painted side panel. The glass for that side panel is reasonably good: double-glazed with at least 5/8” separation between the panes of glass, argon-fill, and a low-e coating. We went with a continuous glass panel to minimize the greater edge losses that occur with true divided lites. I think it will look great when the house is sided.
Cheaper back and side doors
For the back door into the porch and side door into the garage we wanted less expensive doors that were going to be well-insulated and tight. We opted for fairly run-of-the-mill fiberglass doors with upper glazing panels; these are also made by Jeld-Wen and cost us about $300 apiece.
These aren’t anything like the wood-like fiberglass entrance door in appearance (you could never mistake them for real wood), but like the front door, they have a polyurethane insulation core. Because there’s less structural reinforcing material in these doors, they may actually outperform the front door from an energy standpoint. I’ll be very curious about this and will plan to do some thermographic (infrared) analysis once the house is completed and lived in to study heat the relative loss through the different doors.
We still need better door options
I think the three exterior doors we ended up with provide a reasonably good compromise in appearance and performance. But compared with other energy features of the house (R-40 walls, R-50 roof, mostly triple-glazed windows, etc.), the doors are still a weak link.
I would love to see a high-quality, durable, energy-efficient, and reasonably affordable door introduced. Even at the high end — where customers have unlimited budgets and want to create a dream house that can be heated using solar panels on the roof — well-insulated doors are very hard to find. In Europe there are some good doors used for Passivhaus projects, but these tend to be very expensive.
Is anybody looking for a product development opportunity?
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Alex is founder of BuildingGreen, Inc. and executive editor of Environmental Building News. In 2012 he founded the Resilient Design Institute. To keep up with Alex’s latest articles and musings, you can sign up for his Twitter feed.
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19 Comments
Nice entry ... i've had
Nice entry ... i've had similar problem with doors in the past.
Ended up using PUR insulated FG slabs and added my own finish onto it.
I'll be working on a entry door wtihin the next year, design makes for almost 4" thick to get the correct
R value.
Some german hardware manuf. use frame design that seals with vulcanised trippler seal rubers,
and 2-3 additional pressure seals at different location.
Still doors is very challenging part to design for performance.
I'll second that.
For my own Passive House remodel, I eventually settled on a similar wood grain fiberglass door from Therma-Tru and cheaper smooth fiberglass back doors. I did add multi-point locks to try to ensure a tight seal and reduce warping, and that added around $400 per door. They look okay, but I'm not very happy with the weather stripping and sealing. Having lived in Germany for a year, I know what a well-made door looks like. I haven't seen any American made doors that stand up to close inspection.
I hope that will change.
Jason Miller: problem here is
Jason Miller: problem here is the price issues.
Owner of regular houses don't give a damn about energy efficient products, they want LOOKS and price.
Green people usually want efficiency and price.
Door manufacturers care only about profit ( cost ) and looks ( maximize sales ).
But great product to meet high efficiency in entrance door will be high price/cost
(thus less profit) because the buyers looking for high quality products will be price sensitive.
high quality german doors are pricey, but not much more than what regular house buyers agree to pay for "look" doors ( at least here ), problem is that the manuf. profit is lower and this is not a really attractive situation here in north america where everyone wants to be a millionaire !
you can end up "piecing" up a good end product if you take some time to look around for different components, but you will be on your own for assembly.
How about an air lock entrance
Using an air lock on the house we designed does a great job of insulating and blocking the influx of cold (or warm) air. Put a coat closet in it and it is very useful. We used steel over foam with great seals at a very reasonable cost. Only problem is when the paper boy throws the paper at it at about 90 mph. Air lock also lends some privacy if wanted.
I would like to see doors more energy efficient for a reasonable cost.
The hunt is over...for me anyway.
I recently (prior to your post) dug through the links you have listed to the left. Very helpful.
Another website I also found helpful:
http://hammerandhand.com/passive-house-doors
Combing through that information, my intention is to now fabricate a couple of high quality doors in my shop later this year for my house. Some of the key components will be multi-rabbeted stops with weatherstripping, a complete thermal break (not only in the door but also in the jamb), and a multi-point lock system. I'll use Peak Building Products insulation; "Vacupor" at R-30 per inch. I haven't priced it out yet, but I imagine it's expensive. Not sure what wood I'll finish the doors with...maybe cherry?
With that, I should be able to build a door that meets my needs. And hopefully it's not too expensive. I'd like to keep the materials under $500. I'll keep you posted.
Dave
Vacuum insulation in a door
Figuring out a way to incorporate Vacupor or another vacuum-insulation material into a door would be awesome! You might also look at the new Dow Corning vacuum insulation product, which might be more affordable. I mentioned it in this blog:
https://www.greenbuildingadvisor.com/blogs/dept/energy-solutions/few-product-highlights-greenbuild
The challenge will be achieving the strength needed to avoid warping. You could get R-100 but a 1/4" gap at the edge would make the performance no better than a solid-wood door. Some of the vacuum insulation panels use a quite rigid silica boardstock substrate, which could add strength. I look forward to hearing what you come up with. Keep me posted: [email protected].
dave,
variotec's worked out a
dave,
variotec's worked out a VIP'd door [multifunktionstuer] and the section can be seen here: http://www.baulinks.de/webplugin/2010/i/0225-variotec3.jpg
and some details here:
http://www.fenstertechnik-weinfurtner.de/img/passivhausfenster-aufbruch-in-neue-dimensionen.pdf
annnnd if you want to see what some other profiles for PH doors include, PHI's got them on their database:
http://www.passiv.de/komponentendatenbank/haustuer
i've not seen a situation where the material/labor cost uptick for an airlock was less expensive than a really solid PH-level door.
Airlock entries
Plenty of researchers have compared the energy savings of an airlock entry with the cost of the feature. It doesn't make any sense from an energy-saving perspective. It's not cost-effective.
But if you want a mudroom for other reasons -- because it's convenient -- then by all means build one.
Built my own, no pictures
Built my own, no pictures since I sold the house. Took a basic steel/foam door and added a 1/2' foam on the outside covered with brushed aluminum. The foam & aluminum was held back from the edges for the existing door stop & weather strip. Covered exterior of jamb with 1/2 foam plus alum. angle which gave me second door stop and location for foam weather strip. The alum angle is both the jamb and the exterior door casing and gives a weather tight industrial look. On the inside I added 1/4" burly maple ply with contact cement. Good looking, tight door.
Agree an airlock entry is not cost effective unless it is a very usable part of the floor plan.
And an attached garage can serve as an airlock entry for the most sever weather.
Confused by Martin's comment about airlocks
Hi Martin,
I'm a little confused by your comment. What cost is involved in having an airlock type entry? We planned one into our house as much to have the airlock effect as to serve as a mudroom (as you mention) and we actually refer to it as a "catlock" since it also serves to help prevent the sneaky fellas from getting out...
On a related note I used Masonite fiberglass doors. They were nice looking and perform on a par with the Inline fiberglass windows I have. The 1/2 lite I have on the north side of the house is a U 0.2 and the full lites on the south and west sides are U 0.3.
I'm a little disappointed though in the 1/2 lite as it seems to get a lot of condensation on it. Even with the HRV now fully installed (and keeping the house humidity at 40% or less) when the outside temps get more than 5-10 degrees below freezing (as is typical of VT in winter) we have had a lot of condensation on that door in particular and on most of the windows, especially the north and east ones. It's been real problematic on the door because it ends up running down the inside of the door and then freezing in the gap at the bottom of it.
I'm actually hoping that once we get the interior door installed into the mudroom that putting a dehumidifier in there may help reduce the condensation on the exterior door. It's an out swing door. We chose out swings for all our exterior doors since in the winter with the wind blowing they seat tighter. If the de-humidifer doesn't work then we're even considering putting a storm door on the interior to create a thermal buffer on that mudroom door?
Any perspectives from the folks here as to whether either of these approaches has merit or suggestions on any other approaches?
TYIA
- Jay
Response to Jay Hersh
Jay,
If your house design includes an intentional mudroom, you obviously already have an airlock entry. It occurs naturally as part of your home's design. It would seem that your family wants a mudroom, so you are all set.
On the other hand, some house designs don't include a mudroom. In this situation, people used to say (back in the 1980s), "Why not add an airlock entry? You'll save energy."
If you do that, you can calculate the cost of a 5'x5' mudroom. At $80/square foot, it might cost $2,000. (There are many reasons that a mudroom would probably cost more than that, however, especially if it were designed as a bump-out. The door alone probably costs $700 or more with installation.) Then you figure how much energy is saved per year... which turns out to be almost nothing... and you can figure the payback period, which is something like 40 to 120 years, depending on the climate and the cost of the mudroom.
Better = thicker?
In a school I went to there was a solid door between two classroom that allowed one room access to the fire excape. This door was a good 4 inches thick.
It seems to me that having doors that were thicker would be an easy way to make better doors. At one point I looked into making my own doors. (Not rocket science, just fiddly.) I had 2x6 walls, so a 4" door wouldn't have been unreasonable. But just try to find handle sets for thick doors!
Doors for a change
It is nice to see that quality doors are being addressed. There has been a great deal written about high-end windows over that last few months, but doors have been somewhat neglected.
I had been looking at the domestic door manufacturers websites and have found their products lacking with regard to insulation and sealing. Perhaps I am wrong?
Several of the fine European Window producers have much-improved designs (that are also very attractive). Variotech, mentioned above, has doors that that seem well designed. Another one that I saw was Beiber at
http://www.bieberusa.com/sites/default/files/pagesimages/pdfs/Passive%20Window%20Documentation.pdf
Pazen is another window/door manufacturer.
http://www.pazen.eu/downloads/Pazen_Full.pdf
My Questions are: Are there doors really better than we can find domestically? Has anyone had experience with thse types of products? And how do the costs compare?
Passiv Haus compliant doors at a reasonable price.
For my home I have just specified Intus windows and exterior doors. The doors are PassivHaus suitable, triple sealed, vast array of options and colors. The hardware on the doors is amazing.
Price quoted with a 12 inch side window around $1650.
http://intuswindows.com/products/u-pvc/doors.html
and no...I do not work for Intus.
VIP Doors - Some Challenges Remain
Sorry for the late post, have not been able to follow GBA as closely as i would like.
As Alex Wilson and Mile Eliason noted in their comments, VIPs (Vacuum Insulated Panels) seem like the logical approach to increasing door insulating values. After all a 1” thick VIP typically insulates to R30.
But, sadly, it's easier said than done. In the case of incorporating VIP technology into a door extreme attention needs to be paid to thermally bridging.
A 2005 Swiss paper by Nussbaumer et al ( http://www.energie-cluster.ch/ecweb5/de/wissenstransfer/innovationsgruppen/ig-hlwd/forschung-und-entwicklung/nussbaumer2005.pdf) looked at this effect in detail. Despite the fact the VIP in their door insulated to at least R-35, overall (which means including the frame and the sill) the door insulated to about R-6.
In the end this is not much better than a typical North American PU foam filled door, which including frame and sill might insulate to R-5.
So clearly, using VIPs in doors is going to involve more than using them as a 'drop-in' replacement for PU foam.
Besides thermal bridging issues, VIPs present challenges with longevity and durability. I'm not sure that anyone really knows how long a VIP will last, but the often mentioned 25 years is, even if realisitic, in my view, not good enough for a door. And of course an unaware owner or owner's spouse who uses a nail to hang a wreath or door knocker will immmeadiately and unceremoniously end the life of the VIP.
So while there may indeed be a future for VIPs in doors, there will need to be some design perspiration in the mean time.
Stephen Thwaites
Thermotech Fiberglass
Passive house doors
I'm building an "almost-Passive" house (same basic building principles, but will not be certified) in Wisconsin and looked around quite a bit for for windows and doors that might be affordable and energy efficient. In my experience, there aren't many choices, especially for doors, in the U.S. I was going to go with Serious, but they don't do swinging doors and the price I got for a sliding door was ridiculous, so I decided to shop around. I found there are some outstanding choices if you want to look to Europe or Canada and you don't mind waiting four months for delivery. I eventually settled on the Intus UPVC model for both windows and doors. I'm not suggesting they are better or worse than other comparable European/Canadian manufacturers, but they offer a really solid energy-efficient product for what seemed to me to be an amazingly reasonable price. The windows and doors are now installed and I'm in the process of sealing them (which is a bit daunting in itself). I can say that I'm completely impressed with the windows and doors (30 windows, 4 doors and an 8-foot sliding glass door). The windows are standard European tilt/turn, triple glazed, triple locking. The doors are built like the proverbial brick ___house. They are really thick and heavy, outstanding hardware, and they seem so much more solid than doors I see in the U.S. Time will tell how they perform, but at first glance they are impressive. You can design virtually any door you want with any configuration of windows and filler panels you can think of. And the price ranged from $1800 to $2200 per door, including shipping and hardware. (All their prices include shipping). As for dealing with Intus, I have found them to be very responsive to any concerns I may have had. Here's a quick pros/cons list of my experiences in dealing with them:
Pros
• Solid heavy-duty product at great prices
• Easy to work with/ very responsive to issues that might arise
Cons
• Four-month ordering/delivery time frame
• Products are really heavy--you'll need a Cat to offload them from truck and at least 3-4 guys to move them around
• They include brackets to install but no screws
• installation videos/instructions are okay, but there are no instructions on how to adjust doors. PDF manuals and more/better videos are needed.
I'll post again after the house is finished and if any other concerns pop up.
Bristol doors?
Alex - I was looking at Bristol doors. They make claims on efficiency and are definitely price premium. The rep is rescom exteriors in my area. http://iwantnewwindows.com/our-doors/
Because of price, and my limited research at the moment, I have not pulled the trigger on these.
Bristol doors
Chris,
I'm not seeing any real data on the energy performance of those doors. I'd be interested in R-values and air tightness data.
Improving performance of doors we already have
We have lots of doors in our house. I'll mention three: 1) The front door, 2 & 3) Doors of the laundry room. I've been able to insulate these doors for good effect. An improvement, not perfect.
1) The front door is a double and the whole of it is quite large (8'h x 7'w) and made of oak of raised panel design and thickness of say 1/2'' to 1 1/4" or so. My temp gun was telling me I was suffering heat transfer via the door. No surprise. The door faces South and in August with direct sun, the INSIDE of the door was over 110F or 35F above the room temp. The outside temp would run 135F. It was like having a huge hot plate of 56 ft2 to exercise our a/c. Winter showed the door to be cooler than the exterior insulated wall. The door seals are a separate issue. The improvement was to a) strategically locate outside a U.S. flag (4' x 6') so that it's shadow fell on the door in August. I've also fashioned b) a removable solar grate café doors to front the front door when it really gets hot. For the interior, I fashioned c) a removable light framework of oak and placed sheet acrylic inside. It's like a picture frame and the door is still seen through the acrylic. There's a reflection. Sometimes people notice, sometimes not. The handle and lock hardware were unchanged. Now in August, the door is up to 100F or so on the outside and only +1F to 3F above the interior set point on the thermostat. The acrylic performs an insulation role all year while the flag and grate are seasonal only. In case the next owner is not enamored, all can be removed without leaving a trace.
2,3) The doors exiting the laundry room go to the deck facing North and to the garage, East. The laundry room doubles as a mud room for our house in the Chicago area. The doors are normal size and are of painted carbon steel shell with insulation encased. The door to the deck has a window in it. The temp gun was showing heat transfer was occurring and this corresponded to a slight sensible chill in the room in winter despite furnace heating. For this case, I fashioned 2" thick Styrofoam sheets custom cut to the door shape(s). The Styrofoam is held in place on the interior side of the door with magnets and is painted to match the paint of the door. The insulation makes a definite difference in the comfort of the laundry room. The door to the deck was also supplemented with a screen door with glass/screen combinations on the outside and an acrylic insert for the window on the inside. The insulation held with magnets can be removed and leaves no clue they were ever there.
I don't have good data to demonstrate the economic payout. The cost was nominal compared to the thousands mentioned for really good 4" thick designer doors. I know the above designs will never make the architectural digest or satisfy people with $ to build new to demanding energy standards. I'm working with what I have to good effect and I design so that esthetically challenging solutions are installed with reversibility in mind. That way, the price and appearance conscious can revert to their ideals with no scars.
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