INSULATION

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Here is some feedback from people in South Wonston that have used the Thermal Imaging Camera.

Feedback 1:

“We found heat leakage around some windows that we have replaced.

A section of wall was missing the cavity wall insulation but it is too late now to go back to the supplier.

The roof insulation was shown to be adequate.

The front door showed some heat loss but it is not a door that we want to change so have put some insulation around the door. We are looking to do other things such as putting thermal blinds on the door window.”

Feedback 2:

“The thermal camera was very useful in showing up areas where there is/was heat leakage.

The easy stuff was around the top of the cavity wall leaking into the loft space. I addressed this with some extra insulation.

Another area is where my downstairs hard surface floor meets the inner cavity wall, but to address that means taking off the skirting board and using either insulation or expanding foam to seal the gap. On my list of things to do but not yet done!

The camera showed up some areas of the external cavity wall where the insulation is a bit patchy, around the external chimney breast being an example. Not sure how to fix that.

A lesson for me is that when having windows/doors replaced, use the opportunity to ensure the surrounding cavity wall areas are properly reinsulated.”

Feedback 3:

“The imaging camera was very helpful, it showed that the insulation above our two bedroom dormer windows was insufficient. We purchased some additional insulation to correct the problem.

We were very grateful for the loan of the camera.”

Feedback 4:

A longer account on someone’s experiences, we have added some notes below the feedback.

“I didn't achieve what I had expected in using the thermal imaging camera, i.e. I suspected the end/ south facing wall of our house might reveal 'gaps' in the cavity insulation, (1982/ 83 build, blown-in rock wool) and some patches of heat loss under windows. (Note 1)

I surveyed the outer walls from outside and inside late on a 'cold' night. Obvious heat loss only showed around UPVC door frames and the lower door panels. A small upstairs back bedroom that had always been a bit chilly showed two heat loss, patches, inside at ceiling level on the south facing wall. One of these in the corner showed signs of a slight black mould development indicating the possibility of some condensation. The other patch did not show any discolouration.

Up in the roof void I crawled around and above both patches found no disturbance/ loss of upstairs ceiling insulation, which is about 150- 200 mm glass fibre and rockwool matting. (Note 2)

At roof eaves level where the venting is likely to be a pathway for air exchange, I guessed the camera telling me there is a movement of air and its likely warmer air than that outside moving across the 'loft' and hence the aim of the roof void ventilation being effective but indicating the heat loss to the roof void isn't zero! (Note 3) So, consequent to the foregoing I've not found good reason to take action to improve insulation.

Some other factors: 

Double glazing / replacement doors are far from the best, (bought when funds were 'tight'!).

The upstairs window lintels sit above the eaves soffit and are not insulated as, let’s say 'todays'.

We live at a lower ambient temperature compared to many 'like' homes and don't 'waste' heat, (all the same we ventilate but on selected days, i.e. not during wet cold Nov, Dec, Jan weather and we blank off bathroom extract vents, (say Oct to Mar), to avoid outgoing heated air/ incoming gale driven cold air when bathrooms finished with/ not in use. We have a kitchen extract that we can similarly blank off in extreme windy weather and no other wall vents.  The indoor access door to the garage is heavily draft proofed and the roll-up garage door * has a curtain draped down on the inside, (this also doubles to reduce heat reflected inwards in the summer months due to being east facing/ AM sun). (Note 4)

* bought as insulated slats.

We've now fixed radiator reflective bubble wrap sheeting behind external radiators and have pull down blinds between windows and curtains.

In the worst winter weather, or when away, we erect stiff sheets of builder’s floor protection cut to fit the reveals/ cill/ head and so more or less isolate convecting warm air from the double glazing, especially the patio and back/ kitchen doors.

When discussing solar panels with a local installer nearly two years ago his assessment of our fuel costs was "your bills are relatively low and considering your ages you'll unlikely recover expenditure before you die!". (Note 5)

My wife, grew-up well up in the Yorkshire Pennines, and, I, only half the altitude, on Bedfordshire's Chiltern Hills. Both 30's / 40's semi's non cavity walls/ coal fires and hence a life of frosted inside winter windows and the habit of counting every bag/ quality of coal being delivered. Both just post the 1947 winter, experiences of the 62/ 63 winter and schools where not every class had radiator heating.

We first lived in a residential caravan, pretty damn cold in the winter, and a link detached bungalow in Cumberland, as was. 

Our house previous to this was 'all electric'. (Note 6)

Hence, we feel quickly learn fuel cost budget management/ planning over and above childhood experiences!

Hence, I feel I paint a domestic picture of '60+ years of fuel economy'!

There's, also, elements of my, largely, construction industry career having an influence. 

Hope the foregoing helpful/ interesting?” 

Note 1 - It is not always easy to detect gaps in cavity wall insulation with a thermal imaging camera. For a more accurate picture a professional borescope survey will give pictures of what is inside the wall cavity.

Note 2 - Really useful result from thermal imaging and fairly easy to resolve.

Note 3 - Lofts need to be ventilated to prevent damp and it is fine for cold air to be coming into the loft as it’s above the loft insulation laid in the floor of the loft.

Note 4 - If the house was built before 1990, the wall between the garage and the house may not be insulated, as this was not a building regulations requirement then.  Solid wall insulation could be fixed to the wall on the garage side, to reduce heat loss to the colder garage.

Note 5 - If a heat pump is installed to replace the gas boiler, this would increase electricity usage and could change the economics of installing solar panels to significantly reduce the payback period.

Note 6 - To reduce carbon emissions, homes will all eventually need to become all electric. Air source heat pumps are nearly three times more efficient, and so use three times less electricity, than electric wall panel heaters.