2

One person advised me that I'll cut down on the heat loss in my kitchen by installing a storm door. Another said I'd get better results by replacing the door itself, and then I can either install a storm or not, it doesn't really make any difference. I'm confused.

My existing kitchen door is well hung and with no drafts around the edges. However, I think it's at least 40 years old, maybe more. What is causing a problem is that it has some glass panels, and they are made of single pane glass. My infrared gadget, and my hand, are both telling me I'm losing a lot of heat in those glass panels.

Improve this question
6
  • I read all the answers the same. Ignore the door unless you've air sealed your house first. The question really needs to be expanded to be the problem. If the problem is heat loss then replacing the door is almost sure to be the wrong answer. If the problem is that you stand next to this door all the time in the winter and it isn't comfortable due to the heat loss of the glass that's a different story.
    – Fresh Codemonger
    Commented Dec 6, 2019 at 22:33
  • @FreshCodemonger - I used the infrared gadget. When I point it at the single pane glass in the back door, I get a much lower number than what I get when I point it at the picture window in the dining room (6 feet away). The picture window has a storm. So, I figured I would get the same benefit (which is admittedly not huge, but still, it's significant) by putting in a storm door, which costs $110. I don't completely understand your comment.
    – aparente001
    Commented Dec 6, 2019 at 23:39
  • If the goal is energy savings / energy efficiency the best thing to do is air sealing. $110 spent on caulking, air seal tape and weather stripping will be orders of magnitude better for your energy efficiency.
    – Fresh Codemonger
    Commented Dec 9, 2019 at 18:31
  • @FreshCodemonger - There is weatherstripping in place and the door fits nicely. There are no active drafts around the edges of the door. However, 1/3 of the area of the door is single pane glass, and heat is getting lost through those glass panes.
    – aparente001
    Commented Dec 9, 2019 at 18:49
  • I think your focus is on the tree and you are failing to see the forest. Surely there are other windows in your house? I'd get a smoke pen and test for drafts around all your windows. If you have a fireplace I'd test for drafts there. If you find any draft remove trim, air seal and re-install. This will get you the most energy savings. Always deal with air sealing your house before you even think about insulation issues, window / door replacement. After you have a fairly air sealed house, you could start thinking about R-values on windows / door / walls.
    – Fresh Codemonger
    Commented Dec 9, 2019 at 19:17

4 Answers 4

Reset to default
2

I'm going to disagree with the other answers and say that a storm door will provide a very marginal insulation ability. It may not even be worth your time depending on what your actual problems are.

A storm door will protect the main door from high winds which can stop a lot of drafts if that is an issue. High winds can force cold air through the cracks of the door, but in this case, we're not actually insulating - we are providing a form of sealing. The additional physical door and the air gap will reduce air circulation.

A storm door can also help protect the door from debris and keep it cleaner. It can keep leaves, dirt, etc from accumulating on the threshold, and that can improve the life of the seal on the bottom of the door.

Cheap single pane windows on a storm door will do almost nothing for radiative heat loss. The window will feel very cold, and the window on your door will also be just as cold as it is now. A nicer double pane storm door will probably rival the cost of a new main door, so that seems like an odd choice.

If wind and a poorly sealed main door are big concerns, a storm door might be worthwhile, but for general "insulation" purposes... Probably not.

A few sources:

So, forget the storm door. Go with the caulk, spray foam, mastic, and weatherstripping first. Sealing the air leaks is the place to start.

Energy Vangaurd

Blocking wind is essentially mitigating forced-air leaks around the door.

However, the energy savings from storm doors are minimal. Aside from air leaks, doors aren’t a significant source of home energy loss.

Save on Energy

R value of metal storm door with single pane glass: 1.00

Colorado Energy Org

R value of 1. That's not much at all.

Improve this answer
3
  • Wind blowing across a surface (door) will cool it too. But you are correct, it will provide a marginal insulating quality.
    – Lee Sam
    Commented Dec 5, 2019 at 19:59
  • My problem appears to be the single pane glass, which covers 1/3 of the area of the door. So you're saying the best bang for the buck would come from replacing the door itself. There is a screen door already in place -- old-fashioned, no spring -- you can get a very effective bang out of it and if you want to keep the bugs out, you have to make a point of closing it all the way. My children aren't small any more so it works for me. So I don't need a storm door for the screen. You're reasoning using logic and conceptual knowledge, and experience? Can you give me a link or some numbers too?
    – aparente001
    Commented Dec 5, 2019 at 20:21
  • I added some links. I admit I could have just as easily found links that said that storm doors were good at insulating, but I think that you really need to buy a much better door to get those benefits. If wind is an issue, or you like to open the main door when its nice out, by all means, get a glass door. I just don't think it will solve the insulation problem you are trying to fix.
    – JPhi1618
    Commented Dec 5, 2019 at 20:43
1

Does a storm door help prevent heat loss?

Yes, unequivocally. The closed storm door traps a pocket of air between the screen and entry doors. That trapped air significantly slows heat transference from indoors to the great outdoors. How much? From the ACCA Manual J, it looks like adding a storm to any door increases the R-value of the door by about 2.

Here are some better questions to ask:

  • Would a storm door or a new door prevent more heat loss? To answer this, we need to know what type of door do you have now, what type of door you'd replace it with (a steel or fiberglass insulated door?), and which storm door you'd choose. A typical wooden door has an R-value of about 3, whereas steel or fiberglass insulated doors are around 7. If your existing door is not insulated, you can gain about four R by replacing the door.
  • Which is the better value? This depends on your choice of doors. A good R-7 insulated exterior door with small windows can be had for about $250. Storm doors range from half that to twice that.
  • Which is the difference in cost between a storm door and a new insulated door with thermal pane glass? Use this to calculate the $/R of each choice.

I replaced one of my exterior wooden doors recently with an insulated fiberglass door. The before/after infrared photos can measure the difference. We can also hear the difference, insulation also blocks sound transference.

Depending on your climate, it might make sense to do both. In my climate (PNW), the convenience of not having another door to deal with upon every entrance/exit is certainly worth the potential loss of 2 R. Doors are a very small proportion of the walls so they don't make a huge difference in heating, unless they're not air sealed. In northern Michigan where I grew up, the winters are much colder and everyone has storm doors.

Improve this answer
1

If you replace the door with another wooden door with a single pane of glass, you won't see any significant benefit. Unless you go to an architectural salvage yard, you'll probably have a difficult time finding another wooden door with single pane glazing. You can find wooden doors at your local big-box, but they'll come with significantly improved glazing and eye-watering prices ($1500 is about the cheapest at my local favorite).

If you install a brand new door, you'll most likely get a steel or fiberglass door with a foam core. (Doors like this are available off-the-shelf at my local big-box for $150-$300). This will provide significantly better insulation. It will also come with better glass (double pane, low-e coatings, etc) which will show additional insulating improvement.

If you add a storm door, you'll get the added benefits of another layer of insulation (the door itself) plus the trapped air between the doors.

Doing both - replacing the door and adding a storm door - will give you the best possible insulation value.

The question is how much improvement are you willing to spend for and how long will it take for your investment to pay off (both financially and in comfort factor).

Improve this answer
0

Yes a storm door will help prevent heat loss. Heat loss is measured in resistance (r-value or u-value) and generally speaking the thicker an assembly the slower the heat will move through it.

Wood has an R-value of 1 per inch, so if you add an additional 2.75" of storm door plus the air space you'll add at least R2.75. Current triple pane 2 surface triple low-e coated windows can achieve close to R7.

But having both the old door and a new door in front of it would certainly prevent more heat loss than just replacing the old door.

Generally speaking if you are worried about energy you do air sealing first as that is the cheapest and most cost effective way to reduce heat loss. A good book is :

Insulate and Weatherize : For Energy Efficiency at Home

Also a link to energy.gov that talks about doors:

https://www.energy.gov/energysaver/design/windows-doors-and-skylights/doors

Improve this answer
3
  • The storm door would not be made out of wood. It's just a simple storm door from Home Depot that I was planning to put in. // Not sure I need to do any more weatherstripping, as the infrared gadget is not showing a heat sink at the edges of the door.
    – aparente001
    Commented Dec 5, 2019 at 7:35
  • If the door isn't made of wood even better. Ideally it would be fiberglass skin surrounding a foam core in which case it would be several times better than a wood door.
    – Fresh Codemonger
    Commented Dec 5, 2019 at 7:39
  • I'm not sure it fits that description. I could exchange it -- haven't opened the box. Actually it was from Lowe's: It's either this one or something similar: lowes.com/pd/…. I want to make sure it's clear that I think the big problem is the single pane glass panels in the existing kitchen door.
    – aparente001
    Commented Dec 5, 2019 at 7:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.