Author Topic: More panels!  (Read 4967 times)

BruceM

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Re: More panels!
« Reply #135 on: June 09, 2018, 02:50:15 PM »
Some of the window films as Bob suggested are very good optically and will perform similarly to double pane glass- doubling your window R value to about 2. 

There are plenty of sun angle calculators online for shading.  Deciduous trees can be quite marvelous for seasonal shading.  My Siberian Elms now shade my summer patio from the eastern sun so that it does not heat up.  West walls can benefit greatly from deciduous tree shade or vines on trellis when insulating them adequately isn't possible.

Hugh Conway

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Re: More panels!
« Reply #136 on: June 09, 2018, 02:52:29 PM »
Up here on the coast at 50* N it's quite  cloudy in winter. Around the winter solstice, even if the sky is clear, the sun does not rise above the trees, so we get no solar input. Same for the solar collector for water heating, though the woodstove takes over that chore from October to April. The Listeroid comes in handy for topping up batteries then, and logs about 300 hours annually. We are using about 2 to 2.5 kwh per day.
Re: heat loss through the windows.......even curtains drawn at night help a lot.........and wife likes them! Double layers help even more. Our biggest heat loss is from opening/closing/opening the doors for our old dog to go in and out. Sometimes he can't make up his mind.
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mike90045

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Re: More panels!
« Reply #137 on: June 13, 2018, 03:26:52 AM »
> Our biggest heat loss is from opening/closing/opening the doors for our old dog to go in and out. Sometimes he can't make up his mind

That sounds like feline behavior   :D

glort

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Re: More panels!
« Reply #138 on: June 13, 2018, 06:54:22 AM »

I looked into the window film.

Seems it isn't that great.  I had my doubts. It could only trap a little air between the film and the glass and seems that does not do all that much.

I'd like to go back to my original idea of removable frames with a transparent covering.  Going to have to be some big arse frames but the idea of doing all those little individual panes of glass in all the feature windows was never going to fly with the film. Take forever.

With 5 cats and a sooky dog, opening doors here can be a pain as well.
 Got to get round to putting in that cat flap.  Much better to open a 300mm sq hole in the bottom of the door than the whole damn thing.

 Did a tally so far on the power for the month. Winter is not Kind.  Averaging about a 25Kwh a day Loss so far.
Did realise I have been forgetting to check one inverter and count it in my daily tally. that's the one with the latest ground mount that I tilted carefully and is doing far better per W than any of the others surprisingly enough.

Not sure if that's a good or bad thing I forgot to include it in the tally.  Means I have been making more solar than I thought.  Does not change how much we have been using beyond that.

Maybe I'll look at tilting those south side panels afterall.
Which is the scary part.

BruceM

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Re: More panels!
« Reply #139 on: June 13, 2018, 02:36:54 PM »
Film has the same effect of double pane; adds R1 to your R1 single pane. That cuts your loss in half.  An insulated shutter for night is much more effective but is a building project.

I only use film on one window (already is double pane) for the winter; the frame sweats too much otherwise.

glort

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Re: More panels!
« Reply #140 on: June 15, 2018, 01:42:28 PM »

Had a Duuuh moment tonight thinking about this. Yes, a lot of what is discussed here stays in my everyday thoughts especially when it's something practical.

Instead of doing film on the windows or making up frames to mound a plastic film, I already have them, bloody flyscreens!
They are on every window here and while they don't cover the entire area of every window as there are still large areas of fixed glass, Just getting some sort of plastic and putting it inside the screen and sitting that back in the window would be a real good starting point.

Now, I just have to find rolls of suitable Film.  Not too wide, not too narrow, not to stiff, not to thin and weak.
Therein lies the challenge.


Was reasonably cloudy here today. Bit sad I wake up when it's still dark most mornings and look at the dawn checking for clouds.  Bout 7-8 am I have a fair Idea of the day but it's been sunny in the mornings and clouding over later. Did that today.
Was pleasantly surprised when I did my 4pm rounds to see I have made 3 Kw over all today. Wouldn't have expected that as I had the air on a lot last night as it was very chilly.

All up today made a worthwhile 41 Kwh. Surprising but very welcome.  Can still do reasonable power in the sun in winter but boy those over cast days send things backwards at a frightening rate.

Had an old friend come out tonight to see the place for the first time. Her kids and ours went to a pre school playgroup together and we have been friends ever since. She was marveling at the place and saying it was her dream home and how she would love something like this. I said sell the 2 Homes you have and you could have any place in the area plus Change which you'd need. She asked why and I said the running costs are significant.

I'm lucky because the panels are saving us significant money even if we are going backwards on power. Saved $12 on power TODAY and around $6-8 most days this month. I hate to think what my brother in law around the corner will pay for  his power bill this quarter. may be offset because I think he has a gas space heater but 6 of one and half a dozen of the other.  It's still all significant cost just to keep the place warm.

glort

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Re: More panels!
« Reply #141 on: June 25, 2018, 12:27:56 AM »

After a lot of overcast weather, the sun is finally coming out better and I'm starting to make some decent power from the solar again.

Last week was (mon to sun) 35.8 Kwh, 22.5, 37.9, 27.8 ( solstice) 46, 42.3 and yesterday, 41.9. 

Previous week started slow but picked up...  20.9, 21.5, 32.1, 42.8, 40.9, 42.4, 44.3. 

For the month, I'd down 307 Kwh so far. That's about  $92 at what I pay.  Not bad I spose.  I'm about half way through the billing quarter and with the better weather I'm going from being down 20-30 Kwh day to 0-6. had the occasional day where I was up a few kwh.

I think I'm at about the limit of the EFFECTIVE winter generation I can do now.  All the North facing roof is taken up and the east is too shaded to worry about and the west produces crap output in winter. I'm reluctant to do anymore on the west roof ( other than maybe dedicated pre heating of water) because once summer comes I expect to be doing maybe 80Kwh a day which will be far more than I can use going on what we pulled  down last summer.

Really going to have to have a Non electric heating system for the place next year.
The days are generally not too bad but the Nights when it hits freezing are another matter and where all the power is going.

I have been monitoring the walls in the place by hand and I'm reasonably sure they are insulated OK.  They have nothing like the icy feel to them the windows have.  They are like cold panels in a fridge.  I found some plastic thick is opaque in the form of Builders plastic. It's 100Um and seem just up to the job of being put under the flyscreens.

I'm also noticing how cold the tile floors are. the place is on a slab and the bathrooms seem the worst of the cold leakages. Been keeping the doors closed on them but you can really feel how icy they are when you go in. Being both on the west side, I was keeping the doors closed on them in summer because they were like hot boxes.  Pretty poor design as usual with no regards to energy efficiency at all.

I'm going to look at blinds for the north end of the place as it's lovely and warm, even too warn right now in the middle of winter and in summer it's just a joke.  Shading that I think will make a huge difference.
The west side I'm more in 3 Minds about.  I might put a much larger verandah over the other end of the house and extend it out. IF we do that I'll take the existing roof and put it down this end of the house. That will shed this end a lot in summer.  I don't detect any warmth coming though now so nothing to loose there really.

I could do a solar panel awning / shade that end which would again keep the summer sun off and contribute something for cooling anyway or I could go the retractable blinds like I want to do the other end.  I favour the solar arrangement over the blinds but will have to think about how to construct it so it looks asethicaly pleasing not a tacked on.


BruceM

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Re: More panels!
« Reply #142 on: June 25, 2018, 03:34:49 AM »
Cold tile on slab floor usually means exposed slab or stem wall outside with no insulation. (Foamboard and metal or foamboard and cement board.) Consider adding some- even a little will help greatly.  If there's a concrete walk outside against it, you're screwed.

Our night time temps are creeping up, I could only get the house down to 74F by this morning. 78F now, too damned hot for me.  I need to work on the inverter and then water chiller for in-slab cooling.




LowGear

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Re: More panels!
« Reply #143 on: June 25, 2018, 06:38:52 PM »
R values are not linear.  R2 is not twice as good as R1.  R1 is the butt kicker.  I seem to remember R10 being rated at something like 90% efficient what ever that means.  And R20 being  something like 93%.  Okay, time has taken it's toll but the relationship is close to those numbers.

In fact, back in Washington state those liberals passed a law making window sales people stop saying that R2 windows were cost effective because of energy transfer.  Quality of life - Yes!  Heating - cooling bills; No.
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BruceM

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Re: More panels!
« Reply #144 on: June 25, 2018, 07:15:09 PM »
Alas, Casey,  the loss through the window glass alone, R2 really does have half the heat transfer as R1. The R scale really is linear.  Marketing types will make up all kinds of nonsense, but there is no such thing as "efficiency" in R values. It only relates to the rate of heat transfer.  Physics, not BS.  R1 is the heat transfer rate of 1 inch of soft pine.  Most blond foam boards (isocyanurate) have an R value of 6-7 per inch.  Straw bales are about R 2.5 per inch.  The insulation and building industries have done a great job at marketing BS, and I know one former building inspector who actually believed that 1/8 inch of fiberglass with a foil facing on the outside of a block wall was going to insulate his home to some fantastic effective R-value as claimed by the seller.  He had to throw 8KW in space heaters to supplement his in floor heat- even combined they could not keep up on windy cold nights. 

https://en.wikipedia.org/wiki/R-value_(insulation)

The R value of the insulation is often defeated by thermal bridging by wood (R1 per inch) from siding to wallboard, and also for fiber insulation, by air infiltration...thus the (typically shoddy) use of wind wraps.

Window loss is only a modest percentage of the total of outside surfaces and losses so halving your window glass loss may mean diddly squat in your power bill.   In a well done, super insulated home, window losses dominate; by the thermal model I used for my home design, my modest sized double pane window losses are now 50% of my total loss. It also is confirmed when I cut my 15F overnight house temperature drop by almost half when I cover them with Astrofoil (similar to Reflectrix- foiled double bubble).





 




LowGear

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Re: More panels!
« Reply #145 on: June 25, 2018, 08:50:49 PM »
Damn Readers Digest and all of the dead legs I've suffered because some pervert left them next to the toilet.

But on a slightly different note.

I had a revelation while pulling weeds this morning and it was inspired by one ajaffa1's recent posts.

I have become somewhat of a bore on anti petroleum and coal energy production.  I apologize.  This is my favorite forum and I will be getting back to basics from now on no matter how much I'm baited (see, I'm the victim).  Thanks for your time and energy.

Aloha
« Last Edit: June 25, 2018, 08:57:06 PM by LowGear »
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glort

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Re: More panels!
« Reply #146 on: June 26, 2018, 01:45:37 AM »

Thanks Bruce.

I have been wondering about the R scale for a while. Asked a number of people and no one knew.
I have something to relate it to now and I was wondering about it being Linear.

I'm surprised about what you say with windows not being a big heat loss.  I would have sworn they were the main culprit here.
In the bathroom which is on a corner with 2 almost floor to ceiling 900mm wide windows, I'm sure I can feel the cold decending from them down onto the floor. It feels like there is a draft. I was standing ther the other night feeling the difference between teh wall and the window and I was going to go get some of the wifes incense sticks an see if I could use the smoke to show what I thought with the falling air mass.

I'll get some of that builders plastic and give them a go. they are the easy ones to do because they are frosted glass so no one will complain about not being able to see out and no one is going to be opening them for months yet.
I keep the door shut to that and the other bathroom that also has a big window and is on the west side of the house. They radiate cold in winter and a ton of heat in summer.  Going to have to put some sort of shading up soon.

With regards to the slab, May be a lost cause there.  At a rough guess I'd say 25% is up against concrete paths. I'm lead to believe that would kill the effectiveness of any insulation I put round the rest.  Not sure what one would use for that anyway or if it would do any good. The walls are brick and sat right to the slab edge so there is really two exposures to the cold not just one.

Wish this discussion had come up 18 Months ago. I would have been much wiser and had a very different outlook on which home I bought.
that said, I doubt there are many/any better than any others here. Maybe more north facing roof would have been as good as it got.
 That would be a huge advantage for winter solar generation. East west is useless in winter.

BruceM

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Re: More panels!
« Reply #147 on: June 26, 2018, 02:29:55 AM »
Windows can be big loss in an otherwise well insulated house, but how it affects the total heat or cooling bill depends on what percentage of loss is windows.  People get suckered into spending a fortune on double pane windows as a retrofit when their money might have been better spent elsewhere, like insulating shutters or curtains, and increasing other insulation. 

For winter heat loss, look at the total outside surface areas- walls and ceiling and exposed masonry/concrete slab edge. if you calculate the area of each type surface and it's temperature in degrees below room temperature, you will will have a good measure of the relative contribution of window vs wall vs door vs ceiling vs outer floor area vs inner floor area.  Then you can estimate how your proposed insulation will affect the total BTUs needed in that room.

For windows with solar gain in the winter, insulating shutters are the hands down winner unless you have too much gain.   On my previous home I made the mistake of way too much passive solar gain- all double pane glass on the south (northern hemisphere). The view was awesome and the daytime gain was so sauna-like that windows had to be open to keep it below 85F in the dead of the winter.  But the night time loss was so great that the rooms would be 58-60F in the morning.  That was very educational.  I had to add thermal shutters to all the windows and patio doors.  I later added reflective mirror film on the outside of all the south glass to cut down the gain, which was a huge help in the summer as well.

 For the thermal models, you have crank in all that data plus outside temperature, wind and soil temps and then you can play what-if's to see how it affects your BTU.  That's how I was able to figure out how to optimize my home insulation for my climate while on a low budget (plus 6 years of sweat equity). The biggest bang for my buck was the perimeter insulation; I had no idea that so much heat was lost through the outer floor in a slab home.  That's the reason so many in floor heat (slab) homes are so expensive to heat- heating mother earth is a loosing game.  The earth is NOT a good insulator at all, and even in our arid climate the one place that stays damp even in summer is under the slab and next to the footings.


You will certainly notice the cold convection draft from windows and solving that will help with comfort as well as some heating cost.  Just remember it's the total surface area x temperature drop below room temperature that makes your heating bill. 

For your situation only the parabolic trough solar hot water collectors would work as you must have high temperatures to use a radiator in your forced air system.  Which reminds me-  take a good look at your duct insulation; half your electric heat watts may be wafting out your gable vents and draping additional fiberglass bats over the duct work might be well worthwhile. 

« Last Edit: June 26, 2018, 02:34:50 AM by BruceM »

glort

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Re: More panels!
« Reply #148 on: June 26, 2018, 04:26:38 AM »

Interesting Bruce. A lot to consider there.

Just been out the back for a couple of hours trying to organise my shed. Now there is a loosing battle. So much stuff, far too many memories and even more regrets. How I'm going to get through that I'll never know but I have made a scratch today.

I did come across some sheets of Bubble wrap I think I saved from the new Furniture. I tried My idea and put it inside the flyscreens on the en suite windows.
What flimsy useless things they are. Spose thy hold the fly wire and are designed for that to be right on the edge of their structural limit.  It's not too bad but not sure how well the screens will hold it. I overlapped it all the way round the window edges which was as best I could do. Probably be hard to tell if it makes any difference but can't hurt if it don't help I spose. I know the Mrs will have a spit when she sees it and write it off as me turning the place into a tip with my stupid ideas.

I looked at the rest of the windows and they tend to be half fixed and half sliding glass. I'll have to get something, maybe some timber and make frames to hold the bubble wrap or builders film on those.  Mostly the ones at the back which is the west side that only gets winter sun from about 1:30 Pm till 4 are frosted being for the bathrooms, a toilet and the laundry which doesn't matter about the view there. The rest along the back have an awning over them and blocking the view out those just isn't going to happen.

It would be OK if I ever found a cheap supply of perspex/ plexiglass but that stuff is like poison here.

I have looked at the AC ducting and had it running while I did. It was cold to the touch on the outside and everything seemed well wrapped. All the junctions have an expanded foam like coating. I was up there a couple of sunny days and I was surprised how little warmer it was than ambient below.
I was thinking of putting a fan up there to pull the warmth down but I'm well past that idea.  When I get up there, whatever it is, dust, fibreglass , makes me cough and hack. Sticks right in the back of my throat. soon as I come down, I'm fine.  Better get myself a respirator for next time I go up there.

I got some more batts because I did find gaps in the insulation. Can't find the pieces to cover them so were probably never put in place. I'll do some patchwork and then put the leftover in in main living area's. Might do some good, again, can't hurt if it don't help.

With the walls are sitting on the edge of the lab, is it going to do any good trying to insulate the edges of that? If I ever build a new home ( lottery winning dependent) I sure have a lot of ideas of how it would be done!
You'll also be getting a consulting job on what should be done regards to a variety of things.

BruceM

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Re: More panels!
« Reply #149 on: June 26, 2018, 05:40:41 AM »
Where exposed, slab edges are a big thermal problem both winter and summer unless you have a thick carpet pad and carpet as insulation.  (I think carpets are toxic indoor air polluters myself.)  Check the floor temps from the wall inward to see for yourself and use the temperature change below room temperature time area to figure the contribution to room losses.

A strip of 1.5" (EPS-R9) beveled edge foam board with some metal trim made to cover it and tuck under the siding, in a suitable color works well. Ideally it should go down to the frost level. (Not far for you.)  Most siding companies that do metal work can bend prefinished steel trim pieces to your dimensions. They usually have a wide selection in colors. There are some composite and cement board products used to cover foam perimeter insulation but that's less likely to be useful as a retrofit.

If you look at some plans online for foundations for the latest low energy designs in Germany you will see massive use (10s of thousands of dollars worth) of high density EPS foam around the foundation.  My climate is milder and frost line is only 16 inches so I was able to avoid the special molded foam products and roll my own simpler design.  For my new neighbor's home I had him increase the sub-slab 25 psi  EPS (blue board) to 3 inches for the outer 4 feet, plus the same 4 inches between slab edge and stem wall, and 1" outside the stem wall down to the footing.  The edge insulation is very cheap for it's performance.  The sub slab insulation adds up fast because of the area but the savings in being able to greatly downsize the heating system pays for the foam even before the first fuel bill.  We can hide the 4" of foam between slab and stem wall by having the 12" wall- the inside framing (non load bearing steel studs) sits on the heated/cooled slab.  The top block of the stem wall is only 6 inch to allow for an extra strip of 2" foam only 1 block high.  The second 2" foam goes all the way down to the footing. 

You may be able to find a good free thermal model to play with...it's tedious and time consuming but very educational.