Classic heat leaks - Page 1
Forum section: electronics / general

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 18, 2018, 04:20:19 pm
content: Has anyone else got 'classic heat leak' images they'd like to share? These are my front door and adjacent wall (behind the electricity meter box). I think these images are telling me I should spend less on thermal cameras and more on insulation...Images made with a Therm-App Pro and 19mm lens, ThermViewer, stitched using Microsoft Image Composite Editor and finally tweaked with Paint Shop Pro.More details on these imageshereandhere.

author: railrun
author_rank: Regular Contributor
timestamp: March 18, 2018, 06:32:03 pm
content: Regarding your second picture: is it a water damage?

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 18, 2018, 07:01:33 pm
content: No, not water damage. It is an outside wall but somewhat protected by a storm porch. However, there is an electricity meter box on the outside and the house supply cable comes from there, through the wall, then to the nearby fusebox and distribution point. I suspect the hole in the wall is not sealed. It is hidden by a large wooden plate on the outside and plasterboard on the inside. I expect if I liberally spray expanding foam around the area it might help. But I shall wait for warmer weather.

author: Supercharged
author_rank: Regular Contributor
timestamp: March 18, 2018, 07:14:54 pm
content: Quote from: Ultrapurple on March 18, 2018, 07:01:33 pmBe careful with the insulating foam around the fusebox, it might create a fire hazard, if impropper foam is used.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 18, 2018, 07:19:06 pm
content: A very good point. I will plan with care and choose the product accordingly.

author: FrankE
author_rank: Regular Contributor
timestamp: March 18, 2018, 07:58:18 pm
content: What's the resolution of the Therm App Pro camera?I was out at the oil exhibition and conference a couple of years back and spoke with the reps on a thermal camera company's stand..They advised the resolution on most cameras isn't good enough to pinpoint air infiltration and that I'd be cheaper getting a survey done or hiring a pro camera.My place gets down to 11 degrees Celcius unheated and doesn;t hold heat for any length of time when it is heated in stark contrast to the Passivhaus flat I stayed in when I lived in Darmstadt.

author: MyThermalWorld
author_rank: Contributor
timestamp: March 18, 2018, 08:46:38 pm
content: Great topic!This is a blower door test I did from a DIY blower door I made.The left image is without the blower door and due to hot air rising and leaving around the window, the insulation looks good. But when reversing the air flow by creating under pressure, the cold air is dragged inn the same way revealing the air leaks.

author: MyThermalWorld
author_rank: Contributor
timestamp: March 18, 2018, 09:03:07 pm
content: Quote from: FrankE on March 18, 2018, 07:58:18 pmI would say it's not the resolution that's the most important, but the distance and camera lense/focus distance. And you need temperature differences of 10°C as well as pressure difference. With negative pressure you'll see the leaks from the inside, and with positive pressure you'll see the leaks from the outside. My experience is that you'll need higher resolution to pinpoint air leaks from the outside than from the inside of a building.I've been able to pinpoint the same leaks with my FLIR One (160x120) as with my FLIR E75 (320x240) from the inside of buildings.Here in Norway there is a open space between the wall cladding and the insulation to vent the cladding and prevent moisture. So air leaks has to be detected from the inside in newer houses.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 19, 2018, 09:35:51 am
content: Quote from: FrankE on March 18, 2018, 07:58:18 pmThe Therm-App Pro sensor resolution is 640 x 480 and the NETD was quoted as <30mK. (Mine isveryearly production - serial number 0001. Later production versions may have fractionally higher NETD for better image stability). Focus is manual and is easy to adjust from close-up to infinity.

author: Ultrapurple
author_rank: Super Contributor
timestamp: March 19, 2018, 09:38:16 am
content: Quote from: MyThermalWorld on March 18, 2018, 08:46:38 pmThanks! That really does show how these cameras can reveal where our heating money goes.

author: Pinkus
author_rank: Frequent Contributor
timestamp: March 19, 2018, 10:50:18 pm
content: Quote from: Ultrapurple on March 19, 2018, 09:38:16 amOne hint: if your kitchen fume hood blows the air to the outside (= a non circulating type of fume hood), it acts similar to the blower door test described above. Just switch it on full power (close all doors and windows of course), wait 10 minutes and then check your doors, windows etc. You will be stunned where cold air creeps in!With the kitchen-fume-hood-test you will be much quicker to identify potential problems. See two pictures attached as an example (window and light switch on the wall).

author: eeviking
author_rank: Regular Contributor
timestamp: March 20, 2018, 07:18:41 pm
content: That's a great hint. ThankI all ready know my attic hatch is leaking in air when the fume hood is running full speed. Will see if I can find other leaks when I get home.

author: MyThermalWorld
author_rank: Contributor
timestamp: March 21, 2018, 09:15:35 pm
content: This image illustrates thermal convection in a building quite well. The cold air flows inn under the door and the hot air flows out at the top of the door. This makes the makes a draft in the room. The convection can also be seen on the wall. The room on this side of the room is heated and the other side of the door is unheated. And the temperature outside is -12°C.I added a seal around the door later, and though still leaking a bit as these doors are not made for insulation purpose (due to it's use indoor), it was noticeable on the electric bill.