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IR

Infrared camera now available for Lincoln residents’ use

Wood stove, just getting started

Wood stove, just getting started

Note: a shorter version of this post appears on the Greening Lincoln site here. The infrared camera described there is available for loan to Lincoln residents; perhaps other towns have or will adopt a similar program.

High-tech tools and toys are not the subject matter of this blog. Our focus here is on appreciation and conservation—stewardship and enjoyment—of nature in general, and these 88 (usually) submerged acres and their riparian and littoral surroundings in particular.

They are, however, not unconnected. Farrar Pond was created deliberately by flooding an old pasture, itself the result of several lifetimes’ environmental modification through felling, grazing, etc. And the hollow in which all this took place was created by the recession of a great ice sheet that had scraped much of what is now New England down to bare rock, then flooded selected areas with sand and gravel ground up at the interface. A glacial outwash plain, a few kettleholes, rich bottom-land from millennia of slow re-vegetation and decay and sedimentation. Farrar Pond and its environs are thus the direct result of not one but two major climatic events, a chill and a thaw.

It now seems that events of this cataclysmic magnitude may be influenced by our own choices and behaviors, perhaps above all the needless waste and thoughtless consumption of carbon-rich fuels leading to increased atmospheric CO2, with uncertain but probably uncomfortable consequences. It was initially to moderate the carbon “footprint” of Lincoln municipal buildings that Greening Lincoln was first created (as the Green Energy Technology Committee); its remit now extends to energy/resource conservation in many forms.

So sharing knowledge of this new tool indirectly serves our conservation mission, by helping people to conserve energy, with benefits alike to natural environments and to our own physical and economic comfort. It also serves our appreciation and education mission, by enhancing awareness of both natural phenomena (hence the animal and cloud pictures) and some less-natural ones, like why snow melts earlier around certain parts of your house. So, whether for practicality or pleasure, please read on.

Heating/cooling bills too high?
Don’t see red—see infrared!

Baby, it's hot outside!

Baby, it’s hot outside!

i Series

If you’re reading this, you probably have some interest in energy conservation. Perhaps you’re a homeowner, renter or facility manager, seeking to save a little (or a whole lot) on utility bills while helping to preserve our environment. Perhaps you’re a contractor, seeking new business opportunities through helping people and planet together. A teacher or policymaker, looking for ways to engage your constituents in this important pursuit. Or maybe you’re just curious. Whatever the case, Lincoln now has a tool for you that will deepen your vision of the world around us. That tool is a FLIR Systems Inc.  i7 thermal imaging camera, and it looks like this  →

 

Thermal imaging technology, until recently used mainly by military, public-safety and high-end industrial users, is only recently available in a lightweight, hand-held package costing under $2000. Lincoln’s Green Energy Technology Committee has acquired this top-of-the-line model through, specifically for use by townsfolk. It is available for loan, and comes with instructions and all needed accessories.

 

What is thermal imaging?

Visible light is emitted by objects that are hotter than about 1000⁰F, like a candle flame at 1800⁰F or the sun at about 10,000⁰F. As surface rises, light gets brighter and bluer. But at each temperature, there are always more photons emitted in the red than in the blue, and still more in the longer-wavelength  infrared range. People cannot see infrared; we feel it as warmth. Special sensors, however, can make detailed images using these invisible wavelengths. A thermal camera cannot “see” temperature directly; it detects and analyzes emission from objects. Hot and cold surfaces emit different amounts of IR. The camera detects this difference, and displays it as a gray or color scale that self-adjusts to maximize visual contrast. More about the camera and how it works: www.flir.com/cs/emea/en/view/?id=41963 and www.flir.com/cs/emea/en/view/?id=41536

 

What can we see with it?

The camera shows us the approximate temperature of surfaces. While the camera  can’t directly “see” hot or cold air, it shows the temperature of surfaces touched by moving air. Even a small air leak around a loosely caulked window is revealed as a chilly area of wall. So the camera can detect heat gains/losses occurring through all three primary mechanisms: conduction (e.g. through-wall water pipes, single-pane windows), convection (poorly sealed window sashes and door frames, electrical outlets in leaky walls) and radiation (roof facing cold sky vs. wall facing warmer forest). The i7 has a sensing range from about -5°F to about 480°F. Higher temperatures, especially at close range, may harm the expensive sensor element, and should be avoided.

 

What’s it good for?

Almost any situation where you would like to detect small temperature differences. It can therefore be a key tool for improving home energy management. Under suitable conditions, it can reveal loose windows and partially open or leaky storm windows; failed thermopane; wall and ceiling cavities due to improper insulation installation, settling or animal nesting; air leaks of all kinds; under-insulated pipes, water-heaters and other appliances; unexpected energy waste from various devices and more.

“Suitable conditions” means whenever a temperature difference exists—a heated house in winter or a cooled house in summer. Conductive heat gain/loss shows directly. For air leaks, it helps if a wind is blowing air into the test area. (Home energy audits usually require a whole-house exhaust fan to reveal leaks.)

A key use is therefore to identify high-value opportunities for improving wall and roof insulation; sealing around doors, windows, electrical outlets, pipes, etc.;  and adding storm windows and doors. Taking pictures before and after energy-efficiency projects can both reveal any incomplete work, and demonstrate immediately the new benefits.

 

How can I learn to use it?

By using it! Instructions are provided with the camera, and it is very simple to operate. Just take it out of the box, switch it on, and see this very different aspect of the world. And include family and friends: this vision can be very entertaining for children of all ages.

The i7 is an automated, fixed-focus point-and-shoot camera. Though many adjustments are available for special purposes, most people will find “just press the button” photos completely satisfactory. Pictures are recorded as ordinary JPEG files on a microSD memory card, and can easily be saved to your own computer for viewing and sharing. (The 140×140 pixel resolution is suited to energy auditing, and will not reveal identifying information.)

 

So let’s get started.

In these photos, note that on-screen temperatures are only approximate, with emphasis on differences. If for some reason absolute numbers are needed, the camera is capable of 2% accuracy with a little calibration.

Here’s looking at you…
IR_0911 IR_0995 IR_1077
And at some of our friends…

IR_0891

Rabbit on driveway, winter night

IR_0926

Dog on driveway, summer day

Cat on a cold tile floor

Cat on a cold tile floor

 Kitchen sink, water running into drain as it warms up:
IR_0329 IR_0331 IR_0332
 Just looking around, on hot summer days and cold winter nights:
 IR_0382 The effective IR temperature of a clear night sky is far below zero. So even a winter-chilled tree is hot by comparison.  The moon still shines.  IR_1109
 IR_0822  A jet’s contrail (~-50⁰F) is warm by comparison, and clouds reflecting the setting sun are positively glowing.  IR_0862
 IR_0523 ← Unfrozen water stores and radiates heat from deeper below ground, hereabouts steady at ~55°F year-round.

In mid-summer, water remains cooler than air, while floating lily-pads get warm and a snoozing frog gets toasty →
IR_0877


Some artificial heat sources: tea kettle, digital clock, night light:
IR_0320 IR_0309  IR_0323
Some electrical appliances use power even when switched off and unplugged. This toothbrush uses a little power in standby mode, unplugged and turned off. IR_0669
IR_0341 The “wall warts” that run many of our electronic gadgets consume power even when the gadgets aren’t connected. A Kill-A-Watt meter can show surprisingly large aggregate electricity consumption by many small items. IR_0321
 Fans heat even while they cool
IR_0801 IR_0806 IR_0904
 IR_0552 and motion sensors are powered even while lights are off.  IR_0548


Now that we’re accustomed to the general appearance of thermal IR photos, let’s look at some houses.
 IR_0375 ← A well-insulated wall, with a properly installed, high-efficiency thermopane window below. Note the lower-efficiency window at upper left, and some heat venting under the front rake boards. (Latter is acceptable, and part of keeping the roof insulation dry.)


Insulation in this wall may have settled, or hot air may be blowing into the wall space from an unsealed air duct. →
 IR_0467
IR_0545 ← Window tight, frame conductive. Installed correctly; frame just passes some heat by direct conduction. Note some air leakage through shingled wall.

Even a good window will not usually insulate as well as a mediocre wall. Curtains or shades interrupt convection across the window’s interior, significantly reducing heat loss. →
 IR_0388
Both windows are single-glazed, but lower one has a good storm door outside. IR_0312
 IR_0409 A revealing photo: one of the storm windows has been left open, allowing considerable heat to escape through the single-glazed double-hung sashes.Note heat loss through the attic vent, indicating inadequate attic-floor (= interior ceiling) insulation. The small bright spot at left is the kitchen range-hood exhaust.This walk-out basement is at least somewhat insulated within. The exposed foundation is warmed in part by heat conducted up from the ground.
IR_0422 ← Storm windows left open here too, and an old-style fixed has low R-value. Glass does not transmit thermal IR; the figure is a reflection of the photographer.

Same window from the inside, showing heat loss from conduction through unprotected lower single-glazed sash. →
IR_0434
IR_0315 Modern low-E glass in this window is good, but gasket and caulking both leak air.Dark streaks on wall show places where a simple caulk bead later stopped flowing air. Total investment: about 10 minutes’ labor, 10¢ in materials.Result: no more cold drafts around the shower! IR_0338
IR_0672 Bathroom ceiling vents usually leak some air in windy weather, even with internal flapper valve working properly. IR_0334
IR_0656 IR_0318 Duplex wall outlets can leak cold air penetrating sheathing or unsealed openings and blowing inside of wall…
A simple foam insert behind this cover plate easily stopped most of the draft. IR_0643
 IR_0592 ← Double glazing on this skylight failed; window was visibly milky. Fortunately, instead of a $2000+ full replacement (with all sorts of interior mess), the glass could be swapped out neatly in 15 minutes for about $100. It’s worth asking around to find high-service, low-cost contractors!

Slider door is tight (no leaks), but old-style thermopane does not insulate as well as modern low-E glazing. →
 IR_0678
IR_0707 ← Door, storm door both leak badly. Replacing old wood storm door with modern type ended overt drafts. Leakage around inside door still allows moisture to condense on storm-door glazing, so a bit of reusable weatherstripping is stuffed into gaps.

Another warped storm-plus-inner door with much clearance beneath—installed decades ago; rubber gasket since decayed. This exit rarely used in winter, so a “sausage” cushion blocks airflow. New gasketing, new exterior storm door come later. →
 IR_0445
 A look at plumbing
Hose-bib covers are readily available. Total heat loss from bare through-wall pipes is fairly minor, but a freeze can crack valve and pipe, causing an expensive and messy flood—possibly within the wall. IR_0470
IR_0850 Boiler room in summer: all zones cold except loop for water heater. Most exposed piping here was later insulated. Pressure-relief valve (top) must remain clear. Drain valve below also remains exposed as a reminder to bleed tank occasionally to clear out scale and sediment. IR_0852
 When waste heat must be vented…
IR_1170 ← Multi-flue chimney, with unlined flue operating.

Multi-flue chimney with lined flue operating, so brickwork remains cool. →
IR_1114
Heat and hot air can flow in either direction, so similar considerations apply to summer air-conditioning and solar-heat management
Renovating a cathedral ceiling: former attic wall has some insulation; roof none. IR_1016
IR_0906 Warming up the chiller:

← Upstairs rooms are open to air. Downstairs rooms are naturally naturally cool—see especially lower-left window. Idle AC unit in upper-right, cooled by breeze, contrasts with wall warmed by late-afternoon sun.

Powered-up AC unit heats up on the outside, while room interior  chills. →
IR_0946
IR_0988 ← Chilled air blowing into room; window above and plastic sliders on each side conduct heat from outdoors…

while indoor heat gets pumped back outside. →
IR_0951

12,800 volts for you

12,800 volts for you

And all that power has to come in from somewhere…

Unless we chop it ourselves!

Wood stove, toasty-warm

Wood stove, toasty-warm

This useful tool (and fascinating educational toy) was acquired for your benefit—so please check it out soon!

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