# Replacement windows and passive solar design



## michaelthomas (Dec 5, 2007)

I have a home that was built in the early 80s and the front of the house was built with a passive solar system.  Dark tiles, slab and lots of glass.  I feel that on sunny winter days the house is definately warmer than on cloudy cold days, so I think that the system works well.  The original crank out window seals are starting to go and moisure is between the panes.  My wife hates the crank outs and would like to get new windows.
My question is...Is it worthwhile to get a window that will continue to let suns heat into the house to have the passive solar system work, or get a Low E type Argon filled window that blocks the suns rays?  What type of window do you recommend for the passive solar design.  Any brands to stay away from?  I live in Maine so winter is about 8 months out of the year.  Our house is positioned for southern exposure in the front.  The house is well insulated overall.  I run the wood stove 16 hours a day on the week days and 24 hours weekend.  Thank You for your input

Michael


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## slowzuki (Dec 5, 2007)

I prefer fixed glass to crank or slide type units.  More seals are more problems.

In Maine a good quality window can help the gain part of the equation but since we get so few hours of light and sunny days, windows with high r-value (triple glazed) or movable insulation in passive houses are more important.

There are types of glass that are IR opaque so the sun can shine in but warm objects in the room can't radiate IR out.  I don't know the type right off but that is the type you would want.

We have a passive house with the traditional passive mistakes, too much glazing for thermal mass so we overheat and then run out of stored heat by midnight.  I know how to correct it but my wife would not like the looks of it!  Going to make insulated shutters to help mask the problem.


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## Rhone (Dec 6, 2007)

Casements were probably chosen because they're better at air tightness than double-hung.  Your casements most likely shut and latch on 1/4-1/2" rubber seals almost making an air tight seal each time, and the seals will last 20+ years.  Getting double-hung instead, they have about 1/8" bristle material for air sealing the windows slide up/down against.  Obviously the bristles are nothing compared to rubber seals for air sealing, nor wear & tear and I'm not that particuarly happy about how well they work.  I purchased the best replacement windows in my area, fully loaded with Low-E and Argon.  I can feel air coming in through the bristles, and in the morning (when it's 15F) everyone of my windows will have 1-2" of condensation around the seals telling me air is certainly leaking in through the bristles.  Casements are also more expensive & secure than double-hung, my guess they decided their better air sealing justified the extra expense.  

Anyway, I'd work hard NOT to replace those casements as doing so will increase drafts and your heating & cooling bill but who am I to talk my wife won that battle, all our casements (we had 6) went away for double-hung her argument being if we stuck with casements I'm cleaning them, otherwise she'll clean the double-hung (since it can be done on the inside).  With all the projects going on in my house I do not have time to be cleaning windows, and out they went.  

Do you want Low-E & Argon... yes on the North, West, and East in your case since the east looks to be trees.  The south, depends if you're regiment about opening up the blinds/curtains in the morning and shutting them at night.   If you leave the window curtains/blinds open all day/night even in winter you are losing more heat than you're gaining and better off with Low-E & Argon.  If you're one that opens/shuts the south blinds/curtains religiously you should just get the seals replaced and NOT get Low-E nor Argon as even in Maine you're gaining enough sunlight in those south windows you probably don't even have to heat the house during the day.  Wish I had that problem   Your $ is best spent getting the seals replaced, seeing about getting Low-E & Argon in the windows facing the directions mentioned, not getting Low-E/Argon for the south windows, and spending the extra $ on some good blinds/curtains/shades to help keep the heat in at night.  Putting Low-E & Argon in the South side will block enough energy you'll probably need to light another fire/day during the winter and me, I personally go through great lengths and spend a lot of money on trying to avoid burning any more wood than I have to.


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## michaelthomas (Jan 22, 2008)

I live in Maine so we get maybe 10 days where it is just miserable from heat and humidity.  The overhang design is supposed to be built so that when the sun is higher in the sky in the summer that it does not shine directly into the house for very long.  I also have the thermal insulated shades that we roll down during the afternoon to keep the heat out.   I keep a 10000 BTU AC in a window to keep the humidity down on those miserable days.  I don't know if new windows would do much for the humidity.


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## begreen (Jan 22, 2008)

We put in new casements and double hungs year before last. There is no question the casements seal better. Our windows are true divided lites. They don't look like casements. 

For recommendation - I like the Marvin Casemaster Cottage series divided lite windows. They're pricey, but well made. I would get a good thermopane, but not low-e argon in your application.

Here's a shot of the house. Can you tell which are casements and which are fixed on the front of the house? (Side casements are older Pellas.)


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## michaelthomas (Jan 22, 2008)

Windows look great!!
My wife has an unnatural hatred for crank outs.  I can see how they would seal better with wind actually tightening the seal.  There is no way she would be pursuaded to purchase new crank outs
We are looking at doing slide windows.  On the triples the middle would be fixed and the 2 side windows would slide open.  On the doubles, both windows would be able to be open but not all the way.  
No Argon.  Is that so the heat can come in?


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## begreen (Jan 22, 2008)

Thanks. The outside windows in each set open as casements. Marvin makes sliders too if that's her preference, just get a really good sealing window. Yes, let the heat come in. I read up a bit on the argon windows and it seems like the gain diminishes steadily as the gas leaks out. So their performance in 5-10 years is poorer. Seems to me in your climate you would gain more by getting windows with a larger inner airspace in the doublepane or even consider a triple-pane window.


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## ericjeeper (Jan 22, 2008)

Windows is something I actually know a little about.
 A lot of things to consider when speaking of solar gain. Winter is mainly long nights and short days. So really  what good does it do to let 50,000 btus in during the day, if the same window is going to let 300,000btus escape during the night?Due to a poorly insulated glass package.
 The best windows on the market today are triple glazed with a super spacer premium spacer.. Filled with a Krypton gas.Home Guard Windows is making a unit using AFG glass. Getting an R-10 That is two panes with a soft coat Lo-e coating ,one clear in the middle. Filled with Krypton gas. (Krypton is a  heavier gas than argon, Therefore serves as a better insulation.
   Up until about three weeks ago Schuco USA was making one of the finest windows in the US. They just sold out to Four seasons.Bad deal for me.They carried more styles and options than any other manufacturer in the US. Yes a casement window does seal the best. But the Higher end double hungs feature a pocketed top and bottom seal.Meaning the sash itself slides down into a groove in the sill and header. As opposed to a bulb type seal down against the sill. I usually explain how this helps the most like this."Your automobile windows seal at the top and the bottom into a groove to ensure no noise or wind enters the interior space. So why should a house window be any different."
  Double hungs could be made to seal better except everyone wants the tilt in to clean feature.But even as they go now, The new seals seem to do an excellent job of keeping the wind out. Providing they are properly installed.
 Ok I will step off my soapbox for a while..
 Yes I sell and install windows manufactured by Home Guard.


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## jebatty (Jan 27, 2008)

Really pleased with the performance of our Insul8 windows bought from Hurd in WI 15 years ago. When we bought these, I seem to remember that the R rating was about 2-3x the best available from the other quality name-brand windows, although the price was close to 2x the other quality windows.

These are R8 rated windows, advertised to have net solar heat gain even on the north side of the house. Two glass glazings with two plastic films on the inside. All the coatings and inert gas to allow solar in and trap heat in during winter, and stop solar heat gain in summer. Windows are all casement or awning type, as well as large fixed picture type windows. Aluminum clad on the outside, pine on the inside. 

50-year old, single level house with 30 feet of glass facing SW. Even with -30F outside, howling wind, and sun, the passive solar heats the house to 70+F in the daytime. No cold air wash, no drafts, can sit right up to the glass in comfort, regardless of outside weather conditions. Windows never fog, never any condensation, never any water staining of interior wood finish. Even the 2 windows over the kitchen sink do not fog/condense with hot, steamy water in the sink.

We replaced all windows in our house. I doubt these will have a $ payback on energy savings in our lifetime, as they were pricey, but the comfort and maintenance free payback achieved the first winter and the maintenance free pays me back every summer.

IMO, do the research, go beyond the traditional brands, and look for really good windows if energy efficiency and comfort are the goals. My last research showed even R12 windows now are available. Replacing windows with these high-end types can be pricey though.


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## JohnnyBravo (Jan 30, 2008)

BeGreen said:
			
		

> We put in new casements and double hungs year before last. There is no question the casements seal better. Our windows are true divided lites. They don't look like casements.
> 
> For recommendation - I like the Marvin Casemaster Cottage series divided lite windows. They're pricey, but well made. I would get a good thermopane, but not low-e argon in your application.
> 
> Here's a shot of the house. Can you tell which are casements and which are fixed on the front of the house? (Side casements are older Pellas.)



just put the same windows in my dads house. (well very close) they are double hung and seal pretty good, its minus 49'C with the wind chill right now so i think its cold around any window. no condensation or frost though. i guess we will have to see how those seals hold up for the next few years. i love the individual lites, just not the $50'000 price tag. i fairly certain that i will never have windows this nice on my house.


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