Using a FLIR Thermal Image Camera to see where our house is losing heat - Low Carbon Lifestyle Ep41 

Hi Beltran, thanks for the comment, apologies I missed it last year. Absolutely agree that double glazing, and well fit windows, are key to minimising heat loss. Our windows are probably not that great... we decided to go for the cheapest option when we were refurbishing our whole house in 2018. Next time we replace windows, in 10-15 years time, I think I will pay much more attention!

@@TomBray-LowCarbonLifestyle you shouldn't apologize, there are a lot of comments. Hope that your next windows provide some better experience. If you need some info I would love to give you information on the topic.

Sounds like a plan - anything we can do to reduce heat loss is a positive step!

I was surprised Tom didn't mention curtains, and I wanted to ask if they're an option and the benefit of good curtains (e.g. long length so they cover the wood wall too).

Hi Greg, yeah good point - curtains are always a benefit as help add a layer of insulation and prevent air movement, I think my assumption is that most people already use curtains and get the benefit, but that trying to be a bit more ambitious / drastic could help too. 👍

@@TomBray-LowCarbonLifestyle if you still had the thermal image gun could you open/close/change curtains and show us the difference? It's easier and a bit cheaper than getting insulation done. I like thick floor length curtains because they make me feel warm and cosy. For bay windows you can have curtains that are straight to cut-off the bay, potential of that looking nice if you only use the window seat when it's sunny.

Really interested to hear more about this product. Do you have a link to it? Tom

You are talking a lot of sense. Yes there we areas that needed looking into, but rather than surprising me, these were areas I already knew were cold or draughty. I think often the camera picks up heat loss relative to surroundings, so even if you had improved a spot, that bit may well have more heat loss than the areas around it. The key is whether you think your work has reduced draughts or improved insulating properties? Is it more comfortable now? My use of the camera at work is more to highlight significant issues, rather than pick up the detail around a certain feature, and I would use the images to make the case for upgrade or refurbishment - 'look how bad this is!' - rather than to quantify heat loss. And, without being too cynical, colourful pictures like from a thermal imaging camera, really stand out in a report to any organisations leadership!

Hi Stefan, sounds like a wonderful house! But does sound complicated to reduce emissions, I agree with not wanting to impact original features. Your house sounds a lot like my mother-in-law's, who was able to replace windows with sensitive wood framed double glazing that looks 'original' and really helps reduce draughts. There are probably actions that you could do that would help reduce draughts as well through spending a day with a caulk gun, or plugging old fireplaces when not in use, the DIY stuff that can help make small differences. Whether a heat pump could provide heat in a house like that, it's a good question, heat pumps can heat any building if they are sized and installed correctly, with sufficient radiators / heat emitters. However with draughty houses it would mean a large heat pump, working hard, so potentially high energy costs. How is your house heated at the moment?

​@@TomBray-LowCarbonLifestyle Thanks for the suggestions Tom. Currently have gas central heating with quite an efficient boiler - and (cough) a gas converted AGA (just for cooking). This is not at all green - but it was in the house when we arrived and now it's very hard to get rid of. Being gas we can turn it down at night and that knocks a third off the bill. I think we might actually turn it off for the summer now that the gas prices are so high. As bad as it is, I think having this low heat spreading around the house all the time has done a lot to make it comfortable - and it's sort of the 'heart' of the house. You mentioned sealing up draughts but that leads to another confusing conundrum - controlling humidity. I just got a meter and it seems our house is just about right in terms of humidity levels. I've seen people in much newer houses with plastic windows and no draughts having horrendous problems with mould and humidity levels off the scale. Isn't the air in a house supposed to be exchanged four times an hour or something? If that's the case the only heating system worth thinking about would be one of those pumps that extracts the heat out of the vented air.- forgotten what they're called. Sorry for even more rambling - but it's a quandary I've had going round my head for some time now. I'm thinking it might be a good idea to get some solar panels. That way I could probably cover my low electricity bill, heat some water and perhaps in the future use it for an electric car or maybe some electric underfloor heating. Seems like a step in the right direction.

@@StefanMarjoram passive houses, being the epitome of heating efficiency, are completely sealed and in order to deal with moisture issues utilise hear exchangers with dehumidifiers. This is an inevitable consequence of sealing up your house. The issue about the house breathing has much to do with water being absorbed by the render. Many people make the mistake of assuming concrete render won't absorb water IE it's water proof but it isn't. If you waterproof your external walls but moisture builds up inside then it's absorbed by the walls and cannot pass through so the house starts to smell of damp. External insulation can be achieved without sealing up the buildings ability to breath. You just have to use the right material. Lastly, before looking at double glazing you could consider secondary glazing which could be made to blend in with your current windows. Too much is made of double glazing... A lot of it is inferior quality and a lot of the heat loss is actually through the plastic (which is uninsulated) so not that good anyway.

A lot of heat loss in double glazing is through the uninsulated plastic. In Canada and colder countries the frame and entire area around the frame is insulated, foamed and taped ... Shonky Britain we just sling em in there.... Gaps are covered with a thin piece of plastic and jobs a good un

They definitely make a point! I wonder whether we sometimes know intuitively what a thermal image camera can tell us - ie we know a wall or an area of house is often cold. Where they are really useful is spotting areas that are leaking heat drastically, can be quite stark to see a big cold thermal bridge!

Hi Stevem- I haven’t considered that. Very interesting. I’d be interested in seeing case studies of where that has been done!

Do people do this?

Thanks Alex - kind of you to comment Tom

Hi George, apologies for my slow reply to your question, I think the images in this video were taken with an early version of these cameras - www.flir.co.uk/instruments/ex-series/. I suspect their quality has increased since the camera I was using was purchased 5+ years ago. I have also used one of the mobile phone mounted systems and again, I think these are improving all the time. Are you hoping to use one? Thanks Tom

Hi J, Yes that is my understanding too. For us, you can kind of tell in our home where we are losing heat even without a thermal imaging camera, the camera just helped confirm our suspicions! Tom

Hi Lewis, fantastic. Our floorboards are uninsulated, I suspect this could make a significant difference if and when we did it! Tom

@@TomBray-LowCarbonLifestyle if you have a good enough crawl space then hopefully you don't need to lift any flooring.

Thanks for the feedback Marouf - I will try to use more videos that aren't my face!

@@TomBray-LowCarbonLifestyle Lose the woolly hat when you warm up!

We are looking the insulate the exterior walls on the front and rear bay window areas also. Some thermal barrier and K Rend.

Fantastic! We still haven't got our bay window installed but could be an autumn job. Pleased to hear it has made a difference!

Hi Mick, I think it was a Flir One Pro, and a few years old.

Hi Michael, thanks for the comment, something we could think about although we don't really have anywhere 100% suitable. Have you got a greenwall at your house? I would be interested in hearing more. Tom

Hi Homayoun - not got an idea about heat loss from the FLIR camera, but from a heat loss assessment done as part of our heat pump installation. This suggested heat loss from the home, on the coldest day, would be just over 5 kW. Over a year we use about 12,000 kWh of heat energy to stay comfortable and for our hot water use. Hope that makes sense! Tom

@@TomBray-LowCarbonLifestyle Hey Tom, I was thinking about how to convert heat loss to energy loss (GJ). Do you have any ideas? I was thinking about estimating the U-value of my house by using thermal imaging and also working on the Plank Law. Any thoughts on this? Thanks!

Hi Homayoun, we tend to measure heat loss as an instantaneous transfer of heat in kilowatts (kW), and would convert this to energy loss by having that loss of heat over a period of time i.e. kilowatthours (kWh) which could be converted into GJ. We can estimate heat loss using the average U-value of a building (units W/m2.K) and multiply by the surface area (m2) and the difference between the internal and external temperatures (K). Where I live we tend to size heating systems based on the extreme external low temperature (-5°C) and the desired comfortable temperature (maybe 21°C). This can give the heat loss in kW at that temperature, which was calculated for my home at around 5 kW. We then run the system throughout the year which provides up to 5 kW of heat for a number of hours per year depending on the external and internal temperatures. Overall, my system delivered around 12,000 kWh (43.2 GJ) of heat in 12 months after installation, the heat loss varies compared to the external temperature. I hope that makes sense and is helpul? I am sorry, I am not familiar with the Plank Law? Tom

Good question - we have quite heavy curtains that probably do some of the job. Curtains with higher insulating properties wouldn’t hurt too I guess!

Ian - sorry I missed this comment! It may be time to pop round?! When would be good? We could do a video...?!

@@TomBray-LowCarbonLifestyle That sounds good! Pick a day between now and 11 April - I'm around doing a bit of garden DIY and stuff 😁