Keeping my sunroom warmer (making interior storm windows)

[mk1st]

Doax, your efforts are mighty. It is true that having pockets of STILL air will improve your R value but the work you are doing is probably not realistic for most homeowners, including having to put them up/take them down each winter.

In my experience (as a home performance consultant) the best bang for people's bucks is to have insulated blinds installed on the inside of their windows. They usually have to be custom made to fit inside the window frames and the very best ones have a track that the blind runs in. The clients I've talked with who have done this have been very happy and have noticed increased comfort.

One caveat: doing this keeps the heat from your room from reaching the glass (which is what you want) BUT because the glass remains colder you increase the chances for condensation to occur on the glass.

[zick]

Looking good!
I'm in the process of doing the same thing. Mine aren't quite as nice looking as yours but I'm just using scrap material and testing this year to see if they make much difference. If they do, I'll probably rebuild them better next year.

[Daox]

I agree most people won't like having to replace screens with storm windows every season. Its really too bad too considering the major impact these items can have on heat loss.

Insulating blinds are a great way to go too. In your experience, how tight does it have to be to add a reasonable amount of insulation? I have double honeycomb type blinds, but the gaps on the sides are too large to provide any real substantial insulation value. I've thought about adding some type of spacers on the sides of the window sills to lessen this gap.

I don't think condensation will be a problem with these storms. The problem with condensation is that you have a cold piece of glass against warm moist air. With the storm windows, the difference in temperature between the multiple pockets of air should make sure that the plastic layers don't get cold enough to condense water. However, I'll still be watching for it once I do install them.

[zick]

Originally Posted by Daox

I don't think condensation will be a problem with these storms. The problem with condensation is that you have a cold piece of glass against warm moist air. With the storm windows, the difference in temperature between the multiple pockets of air should make sure that the plastic layers don't get cold enough to condense water. However, I'll still be watching for it once I do install them.

This is one reason I am putting these in. We have windows in our bedroom which is connected to our bathroom and we rarely open the curtains. Due to this, I have found that we get a lot of condensation on those windows and it's causing mold to grow.
Since putting up one of the made shift storm window, I have noticed that the amount of condensation has reduced tremendously, if not almost 100%. I'm happy to see that.

[supercellman]

Hi Daox,

Been following this post realtime for the last week or two since I stumbled onto it. Looking forward to see your final product. Definitely becoming one of the better how-to's on this subject on the web. Ive got over 20 windows in my old house Id like to add interior storms to, though as many others I'm looking for the best film product to use in these. They seem tough to find. I like your design but might incorporate a few of my own ideas as well. Keep up the good work!

I have a few questions though:
Do you think the knots in the pine might cause your boards to warp unevenly?
What might you do to combat this?
Do you have kids or pets? I ask because it appears you have a film product that is about 1 mil thickness, and thinking this might be a little weak if you plan on using it year after year or for summer ac season as well. Ive been looking into something between 2 and 5 mil thick. Thoughts?

[Daox]

Originally Posted by supercellman

I have a few questions though:
Do you think the knots in the pine might cause your boards to warp unevenly?

I'm far from a professional carpenter so I can't say how things will be effected over time. I do know I was pretty picky when I selected the boards at the store to make sure they were straight.

What might you do to combat this?

The frames will definitely be stored in a way that keeps them flat.

Do you have kids or pets? I ask because it appears you have a film product that is about 1 mil thickness, and thinking this might be a little weak if you plan on using it year after year or for summer ac season as well. Ive been looking into something between 2 and 5 mil thick. Thoughts?

I do have a dog, and she does get her paws up on the windows here and there. I'd rather not go with a thicker material as it'll block more light from coming through. We'll see how it works out. I'm not horribly concerned at this point. If one or two get holes in them it really wouldn't be that hard to pull off that sheet and put on a new one.

[Daox]

While I'm working to get heat in the garage to finish up the frames, I've come up with a temporary solution to the cold sunroom. In my office (labeled living room), I have bent 3/4 of the fins to be straight on the register (red mark). This makes the flow of air out of the register blow straight into the sunroom (air flow shown in orange). Previous to this (airflow shown in green), the vent was blowing to each side. The blue mark represents the thermostat. The air from the vent was blowing right on it! This was causing a lot of short cycling (detected with my new TED5000) and I'm sure a lot of energy loss because of it. With this setup, the sunroom is now getting within 1-3 degrees of the temperature of the office and is MUCH more comfortable. However, I'm still very much looking forward to installing the interior storm windows as I have now just increased my heating load and thus energy usage.

[RobertSmalls]

That should improve your furnace efficiency quite a bit. My thermostat is likewise very close to my heating duct, so I applied shipping tape to the thermostat to slow down its response. It's not an elegant solution, so I'm thinking about building a duct directionalizer, for lack of a better word.

[Daox]

Glad to hear that. I think when it was short cycling it would turn on every 30 minutes and only stay on for 10-15 minutes max. It was pretty bad.

[footynut]

This is a great idea, here a quicker idea that I do use, but it does block the light as well, I cut rigid foam panels to fit the windows and put t up on cold days, it cuts heat loss greatly, easily fit because it cuts with a sharp razor knife and a 4'x 8' panel is $13.00 at lowes. I know the light is blocked, but the room is warm and is easily installed and removed. because it wedges right in without weather stripping. Just cut acurately one time, and you have window insulators for years to come..