Superinstulated windows

[Drake]

Looks to me like a fiberglass insulation. Wouldn't be that hard to make but I won't ever have a wood exterior door on a southern exposure again. Had one and had to revarnish it every year. The direct sun was very hard on it. As most SI homes have thicker than standard walls a 3 or 4" thick foam core door would be doable. Fiberglass frame and cover would be ideal.

[AC_Hacker]

Originally Posted by MN Renovator

If the normal seal doesn't fail, then having a second seal doesn't seem to be much of an advantage.

I think they are creating an air space for insulation. It may seem like a very small detail, but lots of small details really do add up.

Since they pay 2x for energy compared to us, they're quite motivated.

-AC

[Daox]

After talking with a bunch of people about windows I ended up ordering a pair of Serious Windows the other day for my office remodel. The remodel of the office is kind of my trial run of what I will be doing to my upstairs which has single pane windows and virtually no insulation. For this room I kind of wanted to go all out. So, I went with their 925 series which is the 2nd highest model they have. They are the high solar heat gain version since I'm adding the windows to the room to brighten it up. They are 30" x 60" casement windows. The r-value is 6.3 which is about roughly twice what a normal energy star window is. The cost was very high, just over $1k per window. I haven't bothered even trying to calculate ROI vs a different window. I just kept thinking about things and these windows could very well be here in another 50 years. In any case, I'm looking forward to compairing these windows with my existing newer windows in the house. I'll be sure to snap a bunch of pictures when I get them and when I'm installing them.

[MN Renovator]

Yikes, the best of the best windows are definitely expensive. I've had a little day dream about me walking around the house in December stuffing 2" XPS (R10) into the window cavities with the outside covered in a white or colored bedsheet somehow fashioned make it look like drapes from the outside. Cheaper than windows and complete privacy but no solar heat gain. My energy auditor said that typical double pane energy star windows, even on the south side would lose more heat on a 24 hours than could be gained during the day and that even an R13 wall assembly with less window area is a better bet. I'm curious what R value(actually U value) of window and what level of solar gain is needed to balance this out with the limited sun in northern US or Canada, colder night outdoor temperatures and limited thermal mass to store the gained heat for more passive application.

I'm also curious about high SHGC windows and what you do in the summer until you can grow deciduous shade. I wouldn't mind 'forced/mechanical shade' but when the noon/evening sunny side of your house is facing the street putting shutters, shades, or awnings over the windows would make a house look like the odd one in the neighborhood. I was dedicated to the thought of mounting acrylic with tinted sheet or something over my sunny side windows in the summer but realized that it would be over $200 for just the living room and I wasn't sure how well that would work out but after testing aluminum foil over my port southern side windows in the master bedroom it seemed to cut the heat in that room dramatically with the door shut. 5 degrees lower during the peak sun period from one day to the next with roughly the same cloudless sun and temperatures. Looked unsightly from the outside but I kept them up for two months since I have trees that block the view of those windows from the street but aren't tall enough to block the light coming in. This whole XPS over the windows thing is a thought that is gaining traction, even if it is only a week long trial for the week predicted to be the hottest here. Am I crazy?

[S-F]

The house out here my friend made which has gotten a lot of publicity due to how efficient it's turned out to be has polyiso shades which are air tight. It's just a wooden frame with polyiso in it and covered with some fabric the owner thinks is attractive. She hangs it on the wall next to the window during the day.

[S-F]

Hey AC_Hacker, that door mockup is pretty interesting. I had been planning on buying new doors but I could make that. It's plywood. You could make the door out of polyiso and plywood. Glass can be sourced from a good glass dealer. (About that, I just got a quote of $272 each for the triple pane glass for my 4' 6" x 4' 6" picture windows as opposed to something like $800 each from Serious. WTF?) I imagine that making a crazy, nuts, balls to the wall super insulated door might actually be cheaper than buying a regular fiberglass Jeld Wen door.

[S-F]

Well, I just talked to a rep from this distributor of passivehaus doors in NY. They seem to be the only place selling this kind of thing in the US. Their low end doors are a bargain at $6,000 although I've got my eye on the high end ones (5") for $12,000. And I simply have to have the biometric fingerprint lock they offer. It's only $3,000 extra.


Faugh! I'm experiencing a very profound pain at this moment. I don't know if I should bawl like a little girl or scream a the top of my lungs.

$12,000? Just get a regular Home Depot fiberglass door for $250 and use the extra $14,750 to heat you house for generations to come.

What I'm taking away from this is that I should just glue an R16 sheet of polyiso to the outside of my basement door. R 19 (which is MA stretch code for a wall) instead of R 8, or whatever these stupid nuts million dollar passivehaus doors are. These things are like Italian sports cars. Very sexy, perform well, are going to get you laid and cost a veritable fortune. Then Corvette comes along and says "we can't pay an Italian artist to hang out measuring the suspension tolerances of every car the comes off the line with a vernier so we'll just add an extra computer to control the breaking and call it a day". In the end they made a Ferrari hunter. a 4' x 8' x 2" sheet of polyiso costs about $30 and gives more R than several of these doors combined!

Why is it that people who can afford to have a Ground Source Heat Pump system don't really need the low cost of operation, and people who really need the low cost of Ground Source Heat Pump operation can't afford to have one?


Regards,

-AC_Hacker

Edit:

Just so people know to stay away:

Bella Porta
92 Front St.
Hempstead, NY 11550
(888) 366-7748
www.bellaporta.com

[MN Renovator]

I used to think this was a great idea until I decided what size I wanted my future house to be and found out the true power of insulation and air sealing. I have an R8.3 (u-value 0.12) metal door with a foam core that cost me, I think $120 or so. I bought it to replace one that had glass because I wanted to have one with a peephole so if someone came to the door I could see them without them seeing me before I answered(or not) after getting enough people selling siding, windows, roofing, firewood, etc. and then once I had a no soliciting since, the religious groups of every walk of life were knocking. Even if I build super efficient, I won't mind if I have 21 square feet of R8.3. I'm always wondering if its worth it to build completely passive versus super efficient. Cellulose is cheap and if I limit north, west, and eastern windows and use at least energy star glass without going overboard on size of the windows or the house, getting to peak heat load of 5000 BTU(space heater level) isn't impossible. I've been playing with a heat load calc and even if I use .33 U-factor(~R3) energy star windows, I could have reasonable windows, a back door to a patio, a front door, and a door to the garage and enough glass to light the house and save more over many years than if I bought 'passive standard' materials.

I asked a passive house guy at the MN state fair when they were showing their passive house project what sort of supplementary heat people use if they aren't quite passive on the coldest nights. Since there is no sense in buying a furnace or heat pump to heat a passive house since even the smallest units are far too large and very expensive for sitting idle he said a small space heater or a single baseboard heater is usually all people would have. I also discussed with someone who had a passivehouse that was involved in building a passive house that didn't meet the passivhaus standard. Their ACH50 was in the .80's so they didn't get the label but they told me they have never ever 'turned on the heat' in their Duluth, MN home(almost as far north and cold as it gets in the US) since moving in so they effectively built a passive house that they can't call a 'passivhaus'. Walls were 14" thick cellulose if I remember right.

If money was the only thing that mattered, it's all a little different. If I do the math against the efficiency of my current furnace and removing 6 therms from water heating per month. I used 7.1 million BTU to heat my home November to February this year. Granted I don't need 70 degrees to stay comfortable so it was a bit cooler but If I used the same heat with electricity I would have used 2071kwh or $227 instead of about $80 of gas. If my furnace failed I could have held off on replacing it and just used 3 space heaters(15k btu) instead or ducted my electric clothes dryer to the 3rd story of my house where it would heat the 3rd and 4th floors comfortably enough for our relatively less cold winter than usual. This is with R13 fiberglass+R4 foam 2x4 wall construction. Of course comfort would be at stake and I would have replaced the furnace anyway but it gets you thinking as digging up the ground and the cost of a GSHP begins to make little sense once you get below a certain level of heat load. I started looking at smaller ducted RV heaters(I've seen them usually around 15-30k BTU) with an orifice replacement to make it suitable for natural gas if its possible or maybe just save the connection cost of natural gas and use propane, if not, a well placed single ductless mini-split and a backup space heater might do the trick for heating and cooling a well enough insulated small house. I guess it depends on whether or not someone wants a passive McMansion.

Why is it that people who can afford to have a Ground Source Heat Pump system don't really need the low cost of operation, and people who really need the low cost of Ground Source Heat Pump operation can't afford to have one?


Regards,

-AC_Hacker

[S-F]

Originally Posted by MN Renovator

I guess it depends on whether or not someone wants a passive McMansion.

Yep.

I've been meaning to start a thread here to discuss this recent GBA blog entry:
Occupant Behavior Makes a Difference | GreenBuildingAdvisor.com

This is a comparison between the house my friend made, which I seem to talk about a lot, and a passivehaus made in the same state.

Moral of the story?

I have friends who grew up on rice farms in Japan and they didn't have heat or insulation. No insulation. NO air sealing. None. At all. They talk about feeling the wind in their bedrooms at night and waking up to the top of the fish bowl frozen. They would cook food on a kerosene lamp and opening the lid of the earthenware pot was a highlight of the day because of the warmth. They would leave it cooking all week, occasionally adding vegetables as they ran out. My grandmother told me that as a child during the depression in Buffalo NY she would wake up to find the bathroom wash cloths frozen. When you start living a healthy lifestyle in harmony with the natural motions of the Earth and the universe a decent envelope is good but the real passivehaus lives in ones attitude and lifestyle.

[MN Renovator]

I just read this as it was linked somewhere from the link you just provided:
"In fact, they have a limit for the heating load that a Passive House must be below: 4,750 Btu per square foot per year. A 2000 square foot house, then, would need to have a heating load less than 9.5 million Btu per year, which could be met by a 1500 Watt blow dryer running for 77 days. By contrast, a typical furnace with an output capacity of 60,000 Btu per hour would run only 158 hours, or less than a week. Those numbers for heating include the heat that comes from the Sun (solar gain through the windows), appliances, and the people in the house."
From here: Passive House Appeals to Home Energy Raters

My furnace outputs 57,000 BTU per year and my house is over 2000 sq ft and my furnace ran 124 hours this entire winter. To be fair, I didn't keep my house at 72 degrees, or even 60 degrees and this winter was a mild winter but I figured the passive standard would require less heat than this. It's strange to think that this winters usage essentially fell into a passive amount when my house uses 5 times the energy of what I think a passive house using my own personal standards would use(not accounting for building size).