Friday, January 25, 2019

Presentation at the Agency for Co-Operative Housing

I had the pleasure of presenting to the Agency for Co-Operative housing yesterday, Jan 24, 2019.  Its a 1-hr presentation touching on a number of design points related to Passive House and providing some context to Passive as a design strategy of choice for the coming infrastructure renewal phases in Co-Operative Housing in Canada.

Here is the collection of Slides I used.

Saturday, September 2, 2017

Design Business and Delivering Passive House at MArket Value

Passive Buildings Canada has been busy recently and they are teaming with Yestermorrow to offer the following 2 courses.  Very tempting.

It takes far more than being a great designer and builder to establish a successful design/build business.  Adam Cohen shares his insights in developing a successful business model to produce low energy buildings on time and on budget.   Join several  Toronto based firms,make contacts and grow your business.

Interested in the LEAN process specifically geared to the work you do?  This class will discuss the basics of Integrated Project Delivery (IPD), Passive Building design principles, LEAN construction, work flows specific to IPD, BIM integration and in-depth instruction in the design ~ estimating integration needed for a successful project. It would be amazing to have the tools to run projects smoothly and effectively with all team members on board helping to get to the same goals then this course is for you and your team.

Monday, August 28, 2017

Adding Screens to European Passive House Windows

I recently had the most pleasurable experience of designing an entire off-grid cottage for some awesome clients, including the architecture, the structure, and the energy systems.
A major issue with this house was the insect screens!  We used Klearwall Passive House windows, and they don't come with screens.  This was an inconvenience because the northern ontario cloaction for this cottage is rife with insects.
Klearwall sent me some 'clips' for insect screens, which arrived sans instructions.  Having just received them, I was surprised.  They are nothing more than what is well-known as 'lift-off' hinges.  These ones are black, and came without any manufacturer markings. - Perhaps of asian manufacturing origin?  But looks like something Southco or JW Winco would carry.

This whole issue is a complex one, as the windows have really no provision for the addition of insect screening.  We have to build our own, using these plastic lift-off hinges, which I plan to attempt on our own house.  There is a good amount of friction or grip on the lifting-off motion, so I can see they could work.
In the meantime, I found an article online which has an even simpler solution, one that is just beautiful for cost and elegance.
Here is the link.

Will provide further updates shortly, as I continue to search for that super cool adhesive strip with nubbies that grip the screen - like a specialized velcro.

Saturday, August 13, 2016

Central Vacuum and Hide-A-Hose in a Passive House

My wife was very against central vacuum in the house, and for a long time, we determined not to install a central vacuum system.  (She despised having to carry around the long hose - and she'd had only a little experience of this before, but it was with a very long and heavy old style of hose.  Today's hoses are much lighter and more flexible.)  In addition, we didn't know if central vacuums and airtight houses would work well together - but this ended up being just a small part of the project.  The answer is just to place the central vac inside the house, and do not vent it. - But even venting it might be fine (we've not tried this as yet).

Given the very long time it was taking to build our house, I was able to research this more and more, and I eventually realized that cleaning and maintaining the building was of great importance - and this ongoing job would be done better and more frequently if the cleaning process was made easier and more pleasant - so investments in the building maintenance systems seems a good idea.  Moreover, the lovability of a building is likely to have a lot to do with the ease of keeping it tidy.  A major criticism of larger houses is the effort required to keep them clean, right after the energy required to keep them conditioned.

In the end, I decided to purchase a cheap, used central Vac (it was a decent unit, actually) and install it and see how it worked. The nice thing about getting a cheap used one is that we could clean up the construction mess - even drywall dust, and not worry too much about destroying an expensive unit.

The best central vacuum strategy appears at this time to be the Hide-A-Hose approach, in which the flexible hose is 'garaged' in the rigid tubing inside the walls and frame.  If you are not familiar with this, I encourage you to youtube it.  The needed length of hose is pulled right out of the outlet for vacuuming.  When finished, the hose is sucked back into the outlet by the vacuum force.  This means no coiling of the hose, so very little entanglement, and no carrying hoses around.  I find the costs for this system are overly high (we had a consult with a dealer), so we went about doing what we could to do it ourselves.  The dealer discouraged us over and over again from installing it ourselves, but we did it anyways, and it turned out perfectly fine - really there is no big mystery to it, but I will outlay some of the design points below:
  1. First, the tubing that forms the garage must be dedicated without any tees.  This means the run must be planned long enough to avoid any section with a Tee.  We basically ran the tubing in circles around the room to get the required dedicated length.  We wanted more than one outlet per floor due to the way our space would be used, so our layout consisted of a central pipe with branches leading to each hose 'garage', which would wrap around the room and come back to the centre of the house where the outlet would be.
  2. The tubing is standard central vac tubing, but the elbows must be the the special extra-long radius Hide-a-Hose elbows - they come in 90, 45, and 22.5 deg.  You can buy them online easily enough.
  3. The outlets need to be placed 4' above the floor if the pipe comes from above, and lower if from below - we placed ours at 4' above the floor as all our outlets came from above (so this allows the ergonomic pulling down of the inside hose).
  4. If possible, place the garage tubing in the same horizontal plane - this prevents the hose from falling out of the garage when it is mostly out - but no big deal.  Our first install was with 3.25 elbows, and mostly not in plane - still works fine.
  5. USe 'Rapidflex' tubing as the hose - available online.
  6. The dedicated run for the hose garage needs to be about 5' longer because the rapidflex hose stretches a fair bit sometimes and can get a little stuck in upstream fittings if there is no extra length in the garage section.
  7. Plan your runs very carefully.  Try to get a central location in the house to minimize HAH outlets per floor, and keep in mind the HAH elbows - should be max 3  x 90's per garage, less is better - but our first one is 3.25 (3 x 90 and a 22.5) - and it works fine.
  8. Silicone spray applied to the rapidflex hose helps a lot to make the hose come out smoothly.  We've not used any and it still works fine.
  9. When gluing pipe and fittings, apply the glue only the male part of the joint, to avoid getting any glue inside the pipe.
  10. In my first use of the HAH vacuum, I sucked up a short wire with a little plug on it - it got stuck.  I was able to remove it by disconnecting part of the pipe in the basement and using a shopvac to blow air into the pipe in the reverse direction from which the dust usually flows, and this cleared the jam.  I wish there were clean-out fitting for central vac, but I've not seen any.
  11. The dealer told us again and again that special, powerful vacuums with true cyclonic action were required to make the HAH work.  Well these are only available through them at high prices (about $1000).  I tried my cheap 2nd-hand ACV vac ($150) with the HAH and it works perfectly fine so far.
  12. I complain the prices are high for HAH, and they are.  However, if installation comes with those prices, you might get a good value - but I wanted to install it myself, so the component prices seemed ridiculous to me.  Each outlet (just the outlet) is $230 (includes rough-in kit) - compared to about $10 for a regular central vac outlet.  But I couldn't find any alternative to this.  The elbows are about $15 each online.  ($45 each at our dealer).  The rapidflex hose was about $90 for 30'.
  13. Central vacs appear to be a slow-moving technology (probably due to the sometimes dumb patent protections).  They should have adopted brushless motors a long time ago - but Ametek Lamb only offer one or two units out of their huge selection with brushless motors.  Also I do agree with the true cyclonic action, but not for twice the money.  The self-cleaning filter units seem OK.  Having central vac to clean construction messes seems great so far.  I'd like to install one in the garage as well.
  14. There is a product called Zoom - appears to be a very good value for money compared to the HAH.
  15. Power:  I'm always amazed at how manufacturers market the 'power' of their appliances.  I think most consumers know that the amount of power a unit consumes has little to do with the amount of useful work the unit produces.  In the case of central vacuums, airwatts is a fairly good measure of performance, which describes the useful 'power' of the actual vacuum, not the electrical power going into the machine.  However, there is a measure which is better yet:  This is inches of water column (pressure or vacuum) at a given flow rate.  The better machines seem to offer about 125 inches water column at some 150 cfm.  These two numbers together give you a very clear idea of the suction pressure and the flow rate.  Dust collectors have quite different pressures and flow rates - but they can have the same 'airwatts', which is the product of suction and flow. 
Having installed the central vac now, we have both HAH and regular outlets, I can say that it seems much better to have central vac than not, and the HAH is definitely worth having, especially if can do it for less money than what we were told it would be.  The suctionof a central vac is a lot stronger, and the convenience a lot better, and you never have to go looking for the vacuum, nor do you ever have to drag it around.  It can also be more quiet, since the machine is generally not close to where you are working.
Central Vac Pipe with extra long radius bends for Hide a Hose

Hide a Hose Outlet, with Rapidflex hose

Hide a Hose outlet, rear

Hide a Hose Outlet, front side with door open

Thursday, May 19, 2016

Ontario Government to Phase out Natural Gas for Heating (!!!)

These pics have little to do with my article.  Here's our electrical meter arrangement.
Some of the welded aluminum ducting we are installing.  Smooth interior bore, totally leak free.   Bit of work, but I'm doing all the welding myself, so ...busy.  One of the pics is of stainless material (209 stainless, 3.5" tube, 0.080" wall, polished inside and out, $30/10' tube).  Much more work to weld due to the purging process.  The aluminum is better, but the stainless was got at such a great price - cheaper than the aluminum.  I should have gotten more.

Yesterday the Globe issued an article that the Ontario Government is legislating the phase-out of natural gas or any fossil fuel heating for houses.  They plan to spend 7B on reducing the carbon footprint of Ontario, and the revenues will come from the new carbon cap and trade scheme.
Here's the link:

This is incredible news for a province and country rich in oil and natural gas, with economies dominated by the resource sector, and millions of homes heated with natural gas, and the incredible clout Enbridge and Trans Canada seems have had in recent years with both the Canadian Government and the US government.

I received this news from my clients on the SmartHome project.   As I began sending it out, my own disbelief was mirrored by that of others - and Blue Green Group said 'Its like a dream come true!'  and also 'Is it too good to be true?'.  and 'Lets hope the legislation comes through intact.'
These are comments indicating we are hoping for, and wishing for a transformation that, we've practically given up on based on the lack of changes in legislation over the past decades.  
I noticed my attitude changing right away - First, I was ashamed at my own lack of action on this front - how it was not me influencing legislation, it was not me believing in the people of Canada, and it was not me acting to create this big change.  All I've done is work on my own house, and I've shared some of the things I've learned along the way - but my hopes of achieving a change like this were indeed left in the dust of just trying to manage a house build, a family, and a new business.
But after that, I began to realize I no longer wanted to specify gas boilers for my clients (while some of the houses I work on are electricity only, I still do mechanical designs for clients involving gas boilers).   Two projects on the go right now could potentially be changed, and my discouragement of natural gas will be stronger in all new projects.
And then, I've been looking for a utility vehicle recently - and I began to think hey - I should really be focused on getting an electric truck (they don't really exist right now on the market - but making one seems plausible) - or something really fuel efficient. - while efficiency was on my list of requirements, I wasn't intending to use the vehicle frequently, so versatility and utility were more important.    And then those solar panels I've been thinking about for my domestic hot water - I should take some action on those.
All this stuff. - One action by the government, and my own attitudes have been affected so much -.  Suddenly the idea of living in a carbon-accounting economy appears very real, and the fact that money will be attached to the amount of carbon we produce, seems natural, obvious, and necessary.  Its corny, but I feel like saying 'Canada is Back!'

One of the strategies clearly noted in the policy outline is the intention to condition homes (not sure about other buildings) using no fossil fuels.  This means electricity and heat pumps, both air source and geothermal are to take a big role.  But there is confusion about electric heating, of course.

My Mom asked the following:
I always thought that electricity created a larger footprint on the environment because of the steps needed to generate it?
My response:
There is a big misconception about electricity - it is based on the costs of using it directly for our biggest load - heating - which is generally not good.  However, employing (groundsource) heat pumps, we are able to get about 3.5 times the mileage from every watt, so then it is getting much much better - however, even then it is still more expensive than today's natural gas - and cheaper than propane, only by about 10% (compared with air-source heat pumps)

Electricity generation happens in all sort of ways -and with the solar boom, wind boom, significant nuclear advances on the horizon, and many governments phasing out coal, generation is getting cleaner and cleaner - Of course, in Quebec, a ton of home are heated with straight hydro electricity).  One big thing to watch for is the cost of distribution - losses due to distribution can amount to about 60% of what is produced - so local production is of great importance - but inefficiencies don't always matter if ultimately the practice is in general sustainable.  The main thing is that with electricity, there is every chance of getting off of fossil fuels, and much of our generation portfolio already emits no greenhouse gas.  Continued use of gas simply means NOT getting off of fossil fuels, so legislating away from gas is awesome.

Saturday, June 27, 2015

Solar Water Supply and Desalination

Well there is a lot of news these days and I am constantly bombarded by articles on solar, on renewable technologies, and the like, but we are in a unprecendented energy and infrastructure revolution.
The overall global picture has to my mind the following salient points:
  1. Climate Change, leading to varied phenomena
  2. Energy and Infrastructure Revolution, combined with the IT and AI revolution
  3. Population Decline, massive movements of people, new religious movements, and the rise of global black population, and global trade
  4. Water resource awareness and scarcity
A lot of times the news focuses on one of the above aspects of change in our world, but I saw an article today which brought together both water scarcity, the energy revolution, and global trade.

Here it is:

What I found very interesting about this article are three points which were not greatly emphasized:

California will soon be bringing the massive Carlsbad desalination plant online, but at the same time, another smaller desalination plant is coming online.  The two have big differences in scale, being orders of magnitude apart in capacity and cost.  The freaky thing is that the smaller (Only $30M US) plant is highly competitive economically, and converts 93% of the intake to distilled water, leaving behind only 7% of volume as highly concentrated brine.  The huge Carlsbad plant has a conversion rate of only 50%.  

And here is a link to website video describing the system in greater detail.

So this small system by WaterFX is efficient, produces a brine rich in minerals that is an appealing economic resource, and is small in scale, is scalable, and is ideal for distributed deployment.  There is some complexity to the system, and the smallest unit produces about 65,000 gallons (250 m3) per day, and requires about 6000 SF (560 m2) of space to deploy.  Possibly a bit too large for a rural house property, but could be excellent for a small campus or a community.  Finally, something deeply striking about this technology and approach:  Watering our crops with water that is cleaner than the groundwater - for hundreds of years now, humanity has been making their fields more and more saline by irrigating these fields with water containing salts (freshwater from streams and rivers has some salts).  Eventually the long-term concentration of salts in soils renders the fields far less useful for growing crops,  Now imagine we water the fields with pure H2O - this is likely over time to reduce the salinity of soils.
I feel this is definitely a technology and a company to look carefully at.

There are others in the race to low-cost, distributed water purification and desalination - this time focused more on drinking water.
Take a look at this one:

Looks like a very simple and accessible system, costing some $450, lasting 20years, and requiring no power inputs other than sunlight.  Still in fundraising mode, but also likely to be a major player in the near future.

Saturday, January 24, 2015

Electricity Generation and Off-grid for Low Energy Houses

I was recently involved in two low energy house projects and they were both on rural, undeveloped land.  In these cases, I always ask, is it cheaper to have on-site generation and storage, or is it cheaper to be grid-connected?  Actually, I even ask this question all the time in the city, every time I get my electricity bill - the delivery charges are frequently higher than the electricity charges.

So dimensions of the question go like this:
  1. It is often something like $10k to $20k to create a new grid connection for a rural property.  Wouldn't it be nice to put that money towards electricity storage or on-site generation/both?
  2.  Sometimes there is a microFIT project involved - so if we are going to sell solar electricity to the grid, then we need the grid connection anyways
  3. Electric vehicle - If we are going to have an electric vehicle, then we are no longer purchasing gasoline, but must instead supply additional electrical energy to our vehicles as well as our house - well, do the math and you'll probably find that net zero may often be practical for our houses, but net zero including our transportation? - that can be quite an additional load, depending on how much one travels, or plans to.  While the vehicle can act as a big battery for the onsite storage of electricity, everytime I look at vehicles storing energy for the house, I come up short - either for the house, or for the vehicle - so in terms of timing, this option has yet to prove viable.
  4. Microgrid stability - In one project, there is kind of a significant computer activity in the house.  This owner is looking seriously at back-up generation, but one also needs a transition system - like a battery bank or an ultracapacitor bank  - basically a UPS that gives the generator the few seconds needed to come online in a black-out.  This house is also in a valley, so the back-up generator will be perfect to run pumps for flood protection - Even though we are in a big city, power outages frequently come when there are big rains.
    If we need back-up-generation AND the grid connection is costly, why not forego the grid connection altogether?
  5. Finances:  In one instance, the bank decided what to do, rather than the buyer of the land - The bank's position was this:  Build all services - septic, water, and grid connection, or we won't lend you the money to buy the land. - Sheesh!  They must not have heard of solar PV!  
This question always fascinates me - I get to go out looking for off-grid technologies.  So today I came across this on Gizmag: - the power pallet.  This is a machine which eats biomass, and makes heat and electricity, and it is smallish - relative to many biomass machines.  it produces about 20kW, and costs about $30,000.  Kind of attractive if a grid connection costs $15k and  back-up generator $10k.

Wednesday, January 14, 2015

Thoughts on Hiring Designers and Engineers, and the Design Process

Most residential projects involve little if any contact and exploration with the structural or mechanical designers, despite the fact that all projects present a range of not only challenges, but also opportunities.  As a provider of services in this area, I recommend clients think carefully about their goals in hiring 'professionals'.  One thing I feel is important is that the professional must have a sense of service.  All professionals are privileged to be in their position.  They must endeavor to serve their community as a primary and important goal of their work.  This applies to doctors and lawyers - so also to architects and engineers.  And frequently the first aspect of service is that each time one comes in contact with a professional, one should probably find that they are learning something useful. 

There is much to determine and discuss regarding the mechanical systems, which go beyond heating and cooling, and can include aspects such as;

  1. self-reliance, secondary and back-up systems
  2. Flood, snow, and disaster planning
  3. Versatility, reliability, future service, cost of ownership, etc
  4. Indoor Air quality, comfort, noise
  5. Accessibility (for the infirm, etc)
  6. Home Automation, internet of things
  7. thermal envelope design
  8. electric vehicles, vehicle servicing, hobbies
  9. ecological footprint, energy and water conservation,
  10. Rainwater collection, irrigation
  11. waste management
  12. food production - both for cooking, and for growing
  13. Lighting
  14. Renewable energy generation
  15. Energy and water Storage, recycling, and use
  16. Consumption monitoring
These are broader categories, so wood heating back-up and solar thermal back-up, or ice energy systems, or snow melt would be specific approaches that fit into a given category.
I believe every construction project should consider all of these opportunities, if only briefly in some cases.  Unfortunately, houses and other construction projects are frequently seen mainly as a financial instrument or a domestic instrument, and considerations such as resale value, turn-around time, and costs are over-riding, over-powerful factors.  I have seen many projects in which people build too big a house, and often wonder what they will do with the additional space.  Frequently, there is a feeling that one must maximize the lot coverage  - but why?  I firmly believe we should design houses to serve the existing owners - not the potential future owners - that approach is what led us into ridiculous protocols such as valuing houses by their square footage, or the number of fireplaces - in short, designing for 'resale value' on your own house project is the thing that often perpetuates many of the dumb things we did in the past.

The key point that is missed:
A building is YOUR project.  It should be built to serve you and your life and your goals, keeping in mind the broader community's needs as well.  It has to be something that will serve you in general - not create a problem in one area while making a small improvement in another, as so many buildings have in the past.  We have houses that are ugly, houses that are energy hogs, houses that have poor layouts, houses that are a major tax burden, houses that didn't fit their use, houses that are oriented the wrong way, houses that are disposable, houses that only suit younger people, houses that are always dark inside, and so on.

  If you are too busy to deeply define what the building should do for you, then consider not rushing into it, or be clear that your goals and needs for this project will be determined by others.  A project has the potential to provide very valuable dividends for the owners for a long time.  This can take the form of shelter, money, protection, serving the community, artistic expression, production, among many other benefits.  But a project can also be a big liability and burden both during and after construction.

We all know the three dimensions of project management and outcomes are:
Schedule, money, and quality - but I would argue that schedule and money are frequently going together, while quality stands a little on its own.  When projects are complex and large, quality needs to be carefully understood as far more than 'quality', also intention and opportunity.  A high quality building or project may be built, but it can still be redundant, malfunctioning, or deficient.  Many things have been made that should never have been made.  One who over-emphasizes schedule and cost risks producing scrap at a highly efficient rate.  A common stumbling block is that pre-conceptions and (unrealistic) expectations obstruct the heavy work of exploring and identifying the truest and best intentions and opportunities of a potential project.

So in buildings, and civil projects, give importance to design, intentions and opportunities, against how the project should serve for generations to come.

In other projects, I have been in the situation where what is needed, is mainly to get the permit.  This must be the lowliest task for the designer.  What happens is the client sees no value in the design, as it is little more than a bureaucratic hurdle.  Sometimes, the design fee is substantial, and yet there is no value in it for the client.  So I say, discuss this with your designer and find out if there is an opportunity somewhere, in which value can be created in the process of design.  On the other hand, at the moment, most buildings offer a lot of low hanging fruit, upon which good design may be brought to bear, with the potential for reaping great savings or improvements for the client, not to mention the environment or the community.

Friday, November 21, 2014

Snow on Solar Panels in Toronto

3 in 12 roof (14.0deg)
8 in 12 roof (33.7 deg)
It snowed two days ago - We got the normal 2" of snow while Buffalo got the 50"! (1.5m of snow, in 24hr).
A neighbor recently installed solar on their roof, and there is a bit of snow covering the panels.  The two photos below are to indicate the tenacity of snow cover over the panels.  Their roof slope is 3 in 12 (14.0deg from horizontal).  Ours is at 8in12 (33.7 deg).  As I mentioned, the snow arrived two days ago on a cloudy day.  Temperatures yesterday were below freezing all day, with night time temperatures about -9 deg C and daytime about -3 peak.  Some sun yesterday.  Last night was similar, and the sun came out earlier today so at 10am (when both these photos were taken) it has risen to about -3 C already, and sunny.  You can see the roof angle makes a significant difference.  On the steeper roof, the snow was actively shedding and within about 1/2hr after the photo was taken, pretty much all the snow had slipped off the panels.  It is great when snow slides of panels - it has a cleaning effect due to the slight rubbing.  I'll be monitoring the snow over the next few hours and days and months and updating this posting.  There are is a lot of knowledge and data out there on how much sun solar panels receive based on their angle and local climate, but less information on how the panels shed snow or dust, which appears to be a bit more complex and difficult to figure out (due to a lack of experience).  One thing I can suggest for low-slope panel installations: frameless panels such as these from Lumos (photo from
 - these will probably shed the snow a little more easily, I suspect - but no real data, as far as I can tell.  But I would want this kind, just for the improved appearance.  A number of manufacturers offer them.

Sunday, November 2, 2014

High Efficiency and LED Lighting for Passive Houses, Again

News:  Cree recently announced another breakthrough in LED technology:  a commercially available LED with a new level of efficacy:  200Lm/W  !  This is only a chip at the moment, but it is available for purchase - and this is of great interest to makers of flashlights, at the very least. For actual luminaires, they offer a troffer, 2' x 2' for commercial applications performing at 150 Lm/W, not necessarily with the same chips - I don't know.  Pretty awesome performance, and I think people are already aware of their other items I've mentioned in the past  - I have no affiliation with them, but their news seems to reach me easily.  Here is the troffer (it has a CRI of over 90):

The complexity of switching to LED lighting keeps surprising me.  At first I began to learn about the three main specs:

  1. Efficacy (Lumens per watt)
  2. CCT - Correlated Colour Temperature
  3. CRI - Colour Rendering Index
Armed with just these 3, one goes shopping for energy efficient LED replacements or integrated fixtures. Very quickly, we find ourselves surprised at the field of offerings. The first surprise is that all the major manufacturer's offerings are low-efficacy, offering usually not more than 60 Lm/W. I scoffed at this, in error. The next thing you run into is that there are often no claims of efficacy on some products, and then frequently, there is no certification label. Never mind the CRI - which hardly ever appeared. Then, we were in Costco the other day and found this:

The Luminus product. It lists all three main specs, and carries all the certs, and the purchase price (it was a sale) was $5 ea! Pretty impressive to find a product with this level of efficacy, at this colour, with a CRI of over 85, and at a $5 price.

Yet, looking around we find highly acclaimed products like this one from Soraa:
Which uses a different LED technology - GaN - I assume this means gallium nitride. At 54 Lm/W for the 3000K MR16 bulb, one is not impressed by the efficacy. But look at the CRI - 95% - a figure you just can't find in the common PC (phospor coated?) LED technology.

And then I discovered LED Benchmark ( These are the same guys doing benchmark testing of things like video cards and hard drives. I highly recommend their website, where you can expand your knowledge of LED lighting beyond the three main specs. They also have comparison with halogens. It was there I found that we can go beyond to also look at:
  • Flicker
  • actual performance
...and we find that many of the lesser-known product offerings (the cheap ones generally) frequently do not live up to their claims of efficacy, colour rendering, or even colour temperature. And all those low - efficacy major brands? Often they have sacrificed efficacy for colour rendering and reduced flicker. Having purchased a number of LED products now, I can confirm that flicker and CRI are important measures of light quality and should be given significance in the purchase decision. I am now, unlike before, willing to compromise on efficacy to get a light that has no flicker, and a high colour rendering index.

The photo above shows an LED chip I bought on Ebay.  It claims a 1000 Lumen output.  Using my lab power supply, I found it consumes only about 4W, so I highly doubt the claimed output.  The colour is warm white, as claimed, but the light quality was terrible - I'm not sure why, but probably CRI is low, and flicker high.

The photo above shows an LED chip I bought on Ebay. It claims a 1000 Lumen output. Using my lab power supply, I found it consumes only about 4W so I doubt the output is more than 500 Lumens. The colour is warm white, as claimed, but the light quality is terrible - I'm not sure why, but probably CRI is low, and flicker high.

The following 5 photos show commercial lighting quality hardware. We were very lucky to come across a batch of these on Kijiji and bought about 60 trimless recessed light fixtures (two types shown below - these are RSA brand by Cooper). These are about $200/fixture plus about $65 per trim ring. Costly when you consider a house can easily have 100 recesssed lights. We got them for about $6 ea, so we are installing these - they are low voltage (12V), with a solid -state voltage converter per the photo.

 I was interested to know the quality of the output waveform on these, wondering how the LED lamps would respond. But the output frquency is about 40kHz. A little high for my old oscilloscope to read well.

These are the fixed trims for the RSA trimless pot lights.  There are adjustable ones, and square ones for the square version of these lights also. This is a used one, of which I have only the one.

These are the trimless lights. They come with mounting bars and also butterfly clips, but I just didn't like the flimsy-ness of the mounting, so using wood rails - I got 50 of the white square ones below. An interesting feature is that since these are all trimless, they are mudded right into the ceiling drywall. This means no removing and replacing the fixture - but there is a facility to service them - the fixtures are designed so you can reach inside the opening and remove steel covers to service the wiring and the voltage converter as well.