#365539 - 15/12/2015 04:00
The Pumpkin, and Low-E coating on double-glazed windows
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Locally, as in much of the Northern hemisphere, most new windows on buildings are constructed of two sheets of glass, with an air (argon) gap between them.
In addition, the middle side (against the argon gas) of the pane closest to the interior of the building, typically has a low emissivity coating ("Low-E") to reflect heat back into the building.
Our new home ("The Pumpkin") has such windows. Whilst playing with a thermal imaging camera the other night, we noticed a peculiarity on one side of a matched pair of windows: the left side pane had condensation on the inside of the home, and was reflecting more heat inward than the right side pane.
So something strange was happening there.
A bit of googling revealed a simple trick to check whether/where a window has a Low-E coating: hold a butane lighter (lit) up close to the glass, and observe the reflections of the flame. There will be two primary reflections (inner, outer) from each of the two sheets of glass, or four (primary) reflections in total.
The side of the sheet of glass which has the Low-E coating will reflect a more greenish blue version of the flame than the others.
Sure enough, this works. We examined the two windows, and determined that the left side of the pair had the Low-E coating on the inside (the home) surface, rather than on the argon side. So somebody at the factory must have lost track and assembled the two sheets incorrectly.
So we then decided to check the rest of the house, and discovered one other window with an anomaly: the largest pane on the lower level of the home has no Low-E coating at all!
We'll get the glass from both affected windows replaced under warranty, so no problem there. But the trick with the lighter seemed nifty enough to warrant a posting here too!
This method also works with a Cree flashlight, but the colours are not as obvious as with the soft butane flame.
Cheers Mark
Attachments
Description: Butane flame reflections. Can you tell which one, counting from the left, indicates a Low-E coating?
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#365541 - 15/12/2015 04:19
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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The roof-top solar array is pretty basic: four strings of ten panels each, connected to an inverter unit housed inside the garage. Each panel can generate slightly in excess of 250W of power, for a nominal capacity of 10kW of electrical generation.
This power is fed straight into the utility grid at a high price, and we then purchase (much less) power back from the utility at market rates to run the home.
All lighting in the home is done with LED bulbs and a few "native LED" fixtures. Nothing exotic, but it does help keep the energy usage nice and low.
The rear of the house faces due geographic South, and the main (upper) level eaves were designed by SWMBO to maximize solar gain. In the depths of Winter, the Sun reaches through those large windows into and beyond the middle of the home. On a sunny winter day of -15C outside, the interior can reach 27C or more, just from the sunlight flooding in.
During the heat of summer, the eaves block all sunlight: none at all reaches the (upper level) interior from the South face. This helps keep the home from getting too hot. We did end up running the A/C for about six days this past summer, the hottest on record.
With the East/West alignment of the main axis of the home, we get natural airflow (aka. "cooling") from the prevailing winds out of the West. Just open a window or two at each end, and the central hallway gives a pretty good impression of a wind tunnel.
The home sits on two acres of gently sloping ground, with a private soccer field shared with one neighbour, loads of space for future gardens, natural gas from the street pipeline for heat/cooking, and good high-speed internet. Oh, and lots of space for guests.
Y'all are quite welcome should you find yourselves over this way.
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#365542 - 15/12/2015 05:23
Re: The Pumpkin
[Re: mlord]
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old hand
Registered: 01/10/2002
Posts: 1039
Loc: Fullerton, Calif.
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That's pretty clever, Mark. I don't think I would have thought to check. My house was built in 1947 when heating was nearly free and wind blows through my windows even when closed.
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#365543 - 15/12/2015 11:36
Re: The Pumpkin
[Re: mlord]
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addict
Registered: 02/08/2004
Posts: 434
Loc: Helsinki, Finland
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That's a beautiful home!
Interesting that you discovered these window flaws. Your sample size is pretty small, I wonder if they quality control is really that low, or if your batch just came out of the factory on a bad day. There must be quite a few installations where the customer has no idea.
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#365545 - 15/12/2015 20:43
Re: The Pumpkin
[Re: petteri]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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There must be quite a few installations where the customer has no idea. Yeah, I wonder about that too. Our plan is to get our neighbours interested enough to check their own windows, increasing the sample size. The oldest house on the street was completed less than seven years ago, so they're all roughly the same vintage. [EDIT] Here is a link from a home inspector in the USA: http://caveatemptorlv.com/improperly-installed-low-e-windows/He explains that in warmer climates, the low-E orientation is normally reversed, to reflect heat away from the home. And he finds it quite common to find windows which have it wrong.
Edited by mlord (15/12/2015 22:48)
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#365547 - 15/12/2015 22:36
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 19/01/2002
Posts: 3584
Loc: Columbus, OH
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Great setup! It's amazing how much you can save simply by situating the house correctly and putting some thought into designing things like the eaves or the size and placement of your windows. As a bonus, after construction costs, there's negligible cost (except for normal structural maintenance) for the savings.
Do you heat your water with solar or with gas or electric or some other option?
It's so different than here where people put zero thought into the efficiency of the house because the weather is nearly perfect year round. No thresholds or seals on doors, no weather stripping, single pane glass with no coatings, etc..
_________________________
~ John
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#365548 - 15/12/2015 22:50
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Ah, yes.. the water heater. After much research, we installed a natural-gas high-efficiency tank style heater. Not quite as efficient as a tankless design might be, but any losses from the tank merely contribute towards heating the home. In this climate, that's not really a loss for 9 months of the year. On a related note, there's also a concrete "cold cellar" enclosure under the front steps, which we currently use as a walk-in beverage cooler. Another design detail: the concrete slab for the (lower level) basement has rigid foam insulation underneath, plus a vapour barrier, plus rigid foam insulation around the inner perimeter of the floor. This helps prevent leaking heat to the concrete walls on that level, which are outside of the heating envelope. Think "warmer toes" in the workshop! The concrete walls themselves, as well as all of the awkward joist header spaces, have an inch or so of closed cell spray foam applied to the inside, and then R30 Roxul over that. This seems to be the recommended best practice for preventing mould in basements. Even better would be to have used insulated concrete extrusion forms for those walls, but our construction budget didn't allow for that. Mistakes: well, not too many, though we do regret the brown colour on the lower-level siding. We do love the sunny EPS stucco walls though. And that layer of polystyrene under the orange acts like an insulated wind breaker for the house. Good thing, too.. We get a LOT of wind in this location, something that surprised us and the workers building the place last year.
Edited by mlord (15/12/2015 23:09)
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#365549 - 16/12/2015 00:49
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 30/04/2000
Posts: 3810
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Mark, could you say what the numbers are for your solar production, like cents per kWh out and in? I'm working up a blog post about my own solar, and it would be helpful to have Canadian data for comparison.
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#365550 - 16/12/2015 01:02
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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The Pumpkin is connected to the wires of Ottawa Hydro. They pay us 38.4 cents/kWH for electricity from the solar array. That rate is fixed/guaranteed for 20 years, is paid monthly, and income is tax-free until it pays back the capital cost of the system. The rates we pay to purchase back electricity vary by time of day and day of week, explained here: https://hydroottawa.com/accounts-and-billing/residential/time-of-use/rate-periodsWe expect to bring in between $6000 and $7000 yearly from the system, and pay out perhaps $1200 to run the house. The utility has stated intentions to ramp up their consumption rates to about double current rates within the next few years. But that increase will likely be more like triple than double, given that the main power generation utility is due to be sold off to private investors over the same period.
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#365551 - 16/12/2015 01:46
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 30/04/2000
Posts: 3810
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Wow, they're buying your power for greater than 2x what you pay to buy it back again? That's stunning! Your government subsidy is a thing of beauty. This program pays solar energy producers a rate of 20.9 cents to 24.2 cents per kilowatt hour for grid tied solar power over a contract life of 20 years for projects between 11 – 500 kilowatts. So you're getting all of that subsidy money plus -- more or less -- the retail price of the electricity. I'm pretty sure putting solar on your house was the biggest financial no-brainer in the history of financial no-brainers.
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#365553 - 16/12/2015 03:06
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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For the moment it looks good. They pay us 38.4 cents/kHW from the solar. The system cost about $32000 to purchase/install, so direct payoff looks like about 6-7 years.
They try to keep it at about that level, adjusting the payout downward as new installations get cheaper -- people down the street from us put theirs in perhaps five years ago, at a much higher cost, but with a 20-year contract for about 80cents/kWH.
However, given that the retail price is due to (likely) triple within 10 years, the price they pay us versus what we pay them will equalize long before the 20-yrs is up. It's still tax-free income, until the $32000 is paid off, so pretty good value for now.
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#365555 - 16/12/2015 14:44
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 30/04/2000
Posts: 3810
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So I've been reading up more on your electrical pricing, since it seems so amazingly alien from here. Wow it's complicated. So your incentives are brilliant but the underlying policy regime seems to be amazingly twisted. Or am I missing something?
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#365556 - 16/12/2015 15:07
Re: The Pumpkin
[Re: mlord]
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veteran
Registered: 21/03/2002
Posts: 1424
Loc: MA but Irish born
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However, given that the retail price is due to (likely) triple within 10 years As in the retail price for electricity? Yikes!
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#365557 - 16/12/2015 15:47
Re: The Pumpkin
[Re: DWallach]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Or am I missing something? No, just politicians getting their sticky fingers in too deep. The intent is good --> long term reduction of greenhouse gas production to try and keep the planet habitable. But.. what a crazy mess. The best way for us to deal with it and protect ourselves from the higher rates, was to install our own solar array. Cheers
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#368373 - 18/02/2017 02:58
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Workshop views.
Attachments
workshop1.jpg (249 downloads)Description: South end of the new workshop.workshop2.jpg (228 downloads)Description: Looking West through the shop.workshop3.jpg (217 downloads)Description: Northeast corner of the shop.
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#368374 - 18/02/2017 05:17
Re: The Pumpkin
[Re: mlord]
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addict
Registered: 24/07/2002
Posts: 618
Loc: South London
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Wow jealous of that workshop mark!
Not least of all because it's bigger than our house! Darn living in London!
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#368376 - 19/02/2017 18:25
Re: The Pumpkin
[Re: mlord]
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old hand
Registered: 27/02/2003
Posts: 776
Loc: Washington, DC metro
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#368378 - 20/02/2017 00:44
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Today we got around to setting up another empeg in the new abode. This one is SWMBO's player, in her study. The two-tone bamboo flooring was installed by us after we moved in. The tiny class-D stereo amp just right of the empeg is an $8-$9 special from China, with quite decent sound, encased in mahogany as of yesterday (workshop project). EDIT: The Yamaha loudspeaker under the empeg dates from SWMBO's college years, and like my own Bose 301's, the foam around the woofers was completely shot -- eaten away, like powder. Ordered new foams for both sets of speakers from China (eBay) at a total cost of about CAD$9 (delivered!), and installed them a few weeks ago. All four loudspeakers are now sounding as good as ever again. Cheers
Attachments
Description: SWMBO's empeg.
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#368380 - 20/02/2017 03:10
Re: The Pumpkin
[Re: sn00p]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Not least of all because it's bigger than our house! Darn living in London! Probably not really, but thanks. One thing we have noted is that our vegetable patch (currenly covered by 3' of ice and snow) is about the size of our entire property+house at the old place. Space is good. Cheers
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#368381 - 20/02/2017 12:08
Re: The Pumpkin
[Re: mlord]
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veteran
Registered: 25/04/2000
Posts: 1525
Loc: Arizona
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I thought the shop at my old house was awesome, but it was just a detached 2 car garage in the backyard. Yours looks amazing.
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#368382 - 20/02/2017 13:45
Re: The Pumpkin
[Re: Tim]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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It took a while for the workshop to get to its current state. We paid the home builder to frame/drywall/paint the perimeter, and then SWMBO and I did the rest. Starting with the floor (12"x12" peel'n'stick vinyl tile), baseboard and window casings, and eventually a 38" door, much better lighting, lots of shelving, etc. Here is a pic showing the space just before we moved in, and another showing what it looked like for most of the first year. Kinda like playing one of those little maze shuffle games.. move some boxes to make space to move some other stuff to make space to assemble a machine to make shelves.. etc. It was quite simply amazing to see the contents of our old 388 sq.ft. workshop expand on arrival to fill a 2000 sq.ft basement! That's what lack of shelving does for things. The new shop is just under 800 sq.ft, about double the size of a small 2-car garage.
Attachments
ws1.jpg (268 downloads)Description: Just before The Move.ws2.jpg (252 downloads)Description: The first year or so.ws3.jpg (230 downloads)Description: Some of the wood supply, elsewhere in the basement during the first year.
Edited by mlord (20/02/2017 13:53)
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#368383 - 20/02/2017 13:59
Re: The Pumpkin
[Re: mlord]
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veteran
Registered: 25/04/2000
Posts: 1525
Loc: Arizona
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That floor is vinyl? I wouldn't have guessed, it looks really nice.
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#368384 - 20/02/2017 15:26
Re: The Pumpkin
[Re: mlord]
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old hand
Registered: 29/05/2002
Posts: 798
Loc: near Toronto, Ontario, Canada
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... The tiny class-D stereo amp just right of the empeg is an $8-$9 special from China, with quite decent sound ... What are you using to power that amplifier? 200+ watts DC is a fair amount of current.
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#368385 - 20/02/2017 15:45
Re: The Pumpkin
[Re: K447]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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What are you using to power that amplifier?
200+ watts DC is a fair amount of current. Thankfully only a few watts are needed to fill a room with sound! We're using a 12VDC brick that can supply it with up to 3.3 amps, so good for perhaps 15-18 watts per channel as is. EDIT: I originally tried to run the empeg from the same brick at the same time, but it backfed too much noise to the amplifier that way. So instead, there are now two 12VDC bricks behind the loudspeaker.
Edited by mlord (20/02/2017 16:00)
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#368386 - 20/02/2017 15:53
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Here is a pic showing the space just before we moved in... ws1.jpgOh, just inside that central soffit thing is one monster steel I-beam. Sure, there are I-beams running the length of the basement, but that particular one is holding up a 25' clear span (no intermediate posts). So it is rather thick and extremely heavy. That mongo I-beam was responsible for a nearly 3-week pause in construction of the home, as two flatbed trucks broke down trying to transport it to the site. With a ripple on effect that those weeks were nice dry weather, and the month that followed was more or less continuously rainy. The roof didn't get closed in until the day after the rain finally stopped. The yellow thing running crosswise to it, up among the floor joists, is a pair of quite beefy LVL beams, which are carrying much of the load of a stone wall and wood stove on the level above the workshop.
Edited by mlord (20/02/2017 15:55)
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#368387 - 20/02/2017 16:23
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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We paid the home builder to frame/drywall/paint the perimeter, and then SWMBO and I did the rest. Oh we also had them install basic electrical before drywalling. The idea was that we would need to be able to run a 15A power tool simultaneously with a 12A shopvac, plus other smaller stuff. So we had the electricians install twelve split-duplex 20A+20A 120VAC receptacles around the perimeter for us, all on a single pair of circuit breakers. That kept the cost down and made the shop usable from the get go. After The Move, I added a 240V/30A circuit for the dust collector (5HP blower), a 240V/15A circuit for the tablesaw, and another 240V/15A circuit that is shared between the bandsaw and jointer. Used 12g wiring (rather than std 14g) for those tools to help with motor start-up currents. A further two circuits power the arrays of LED pot lights and bulbs in the ceiling now -- could have put them all on a single breaker, but a fear of being left in the dark with spinning blades overpowered the $15 cost-savings that might have provided.
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#368388 - 20/02/2017 16:32
Re: The Pumpkin
[Re: Tim]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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That floor is vinyl? I wouldn't have guessed, it looks really nice. Yes, it gets lots of good comments. I had something similar at the old place, and was surprised by how well it works: - inexpensive (these 2.5mm thick tiles were about CAD$1.80/sq.ft).
- easy to repair (peel up bad tile, stick down a new replacement).
- it doesn't mind heavy tools rolling around on it.
- Wood and boxes can be slid across it (on purpose).
- friendly to dropped tools (eg. chisels).
- no concrete dust to dull/scratch things.
- noise/vibration deadening.
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#368389 - 20/02/2017 21:04
Re: The Pumpkin
[Re: mlord]
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carpal tunnel
Registered: 18/06/2001
Posts: 2504
Loc: Roma, Italy
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Amazing workshop Mark. And I like how you designed your electric system. I can only DREAM of all that space here in Rome city center. You know what I mean.
_________________________
= Taym = MK2a #040103216 * 100Gb *All/Colors* Radio * 3.0a11 * Hijack = taympeg
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#368390 - 20/02/2017 22:06
Re: The Pumpkin
[Re: Tim]
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carpal tunnel
Registered: 29/08/2000
Posts: 14491
Loc: Canada
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Speaking of garages. We put a fair amount of effort into organizing ours so that all three vehicles can still squish inside during the winter, along with all of the junk we store there.
The key was making use of the 12.5' tall space by constructing a mezzanine across much of the back of the garage, evenly splitting the space. There is just enough headroom both above and below the platform for me to walk around without bumping my head. Taller people beware!
SWMBO parks her Civic in the far right bay, partially under the storage level. The big pick-up truck with snowplow parks in the central area, and my Impreza lives in the left bay.
And yes, that is a home-brew elevator just left of the orange 8' stepladder. It is powered by a 120VAC hoist, rated at 400KG, and will lift/lower anything we can fit onto its platform. Very handy for larger/heavier items.
The photo here is from late summer, before I finished drywalling the rest of the space. We hired painters after that to double-coat it all in white, which really brightened things up. Added more shelving too since the photo was taken.
That's the inverter for the solar panels in the left corner above the work table.
Attachments
garage.jpg (228 downloads)Description: Garage
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