AAC Blocks: Thermal Efficiency of

Peciacake

Peciacake

Well-Known Member
After searching SF forum and other expat forum posts for AAC / Qcon blocks & not being able to find a direct answer to my query I would be grateful for advice / experience re the best method of QCon block construction. A builder we are considering has recommended external walls constructed using 20x20x60 QCon blocks whereas we'd planned for a cavity wall using 20X7.5X60 blocks with a styrene foam sheet sandwiched between to maximise insulation. The builder believes we will achieve the same insulative effect using the single 20x20x60 blocks. Does anyone have a reference guide available or have experience with the single-brick method? Any advice appreciated.
 
Peciacake said:
After searching SF forum and other expat forum posts for AAC / Qcon blocks & not being able to find a direct answer to my query I would be grateful for advice / experience re the best method of QCon block construction. A builder we are considering has recommended external walls constructed using 20x20x60 QCon blocks whereas we'd planned for a cavity wall using 20X7.5X60 blocks with a styrene foam sheet sandwiched between to maximise insulation. The builder believes we will achieve the same insulative effect using the single 20x20x60 blocks. Does anyone have a reference guide available or have experience with the single-brick method? Any advice appreciated.
Click to expand...
Contact coffee as was just recently the last build to use them.

Home Renovation upcoming

Don't worry about the glass doors @Coffee. Just don't clean them. Your dogs will soon leave some tell-tale signs, paw prints, doggy kisses, and muddy scratch marks etc.. I am reminded about when my mother in law paid a visit to our house. I made a special effort to clean the 4-panelled glass...
www.surinfarang.com
 
Peciacake said:
After searching SF forum and other expat forum posts for AAC / Qcon blocks & not being able to find a direct answer to my query I would be grateful for advice / experience re the best method of QCon block construction. A builder we are considering has recommended external walls constructed using 20x20x60 QCon blocks whereas we'd planned for a cavity wall using 20X7.5X60 blocks with a styrene foam sheet sandwiched between to maximise insulation. The builder believes we will achieve the same insulative effect using the single 20x20x60 blocks. Does anyone have a reference guide available or have experience with the single-brick method? Any advice appreciated.
Click to expand...
I would suggest the man to consult is a fellow forum member, @Bandersnatch. He has written an excellent blog called: https://ecohousethailand.com/. Well worth a read.
 
gotlost said:
Contact coffee as was just recently the last build to use them.

Home Renovation upcoming

Don't worry about the glass doors @Coffee. Just don't clean them. Your dogs will soon leave some tell-tale signs, paw prints, doggy kisses, and muddy scratch marks etc.. I am reminded about when my mother in law paid a visit to our house. I made a special effort to clean the 4-panelled glass...
www.surinfarang.com
Click to expand...

@Peciacake
My experience is limited as I have not resided in the new addition.
Finishing waterproofing on roof...touching up painting...waiting on curtains...etc.

So a "reference guide" or/ with "insulative effect" experience I have nought.
 
Peciacake said:
After searching SF forum and other expat forum posts for AAC / Qcon blocks & not being able to find a direct answer to my query I would be grateful for advice / experience re the best method of QCon block construction. A builder we are considering has recommended external walls constructed using 20x20x60 QCon blocks whereas we'd planned for a cavity wall using 20X7.5X60 blocks with a styrene foam sheet sandwiched between to maximise insulation. The builder believes we will achieve the same insulative effect using the single 20x20x60 blocks. Does anyone have a reference guide available or have experience with the single-brick method? Any advice appreciated.
Click to expand...

While waiting to find a more authoritative source of information, this forum thread may be interesting to read: coolthaihouse.com • View topic - Two walls Vs Q-con blocks

As someone living in a 2 storey built using sections of the red-brick method interspersed with standard cement blocks, any other form of construction would be a vast improvement!
 
To answer the OP, I have analysed the thermal efficiency of 2 different Q-Con walls, one being a single wall built with 20mm thick Q-Con bricks, the other a double wall of 75mm Q-Con bricks with a 50mm sheet of polystyrene sandwiched in between. All information obtained from the Internet and references provided.

1620863390901.png
Reference: https://static-marketing-2.onestockhome.com/attachments/581/qcon_handbook_eng.pdf

From the Q-Con handbook, 20mm bricks have a thermal efficiency of 2.342 against 1.079 for the 75mm brick. So 2 x 75 mm bricks would have a R rating of 2.158 against the 200mm brick's R rating of 2.342.

A 50mm polystyrene sheet has a thermal efficiency (R-Value) of 1.32m2K/W.
Reference: https://www.insulationshop.co/50mm_polystyrene_insulation_boards_eps_70jablite.html

It follows, a double wall of 2 x 75mm Q-Con wall with a 50mm insert of polystyrene sheet would have a thermal efficiency or R rating of 2.158 + 1.32 = 3.478. This is significantly more than a single wall of 200mm Q-Con brick that only offers an R rating of 2.342.

In conclusion, your builder has not done the maths! I believe his advice is incorrect. A double brick wall of 75mm bricks with a 50mm polystyrene sheet in between has an R rating more than 1.6 times higher than a single 200mm wall.

N.B. I am not an expert in this field, I have only analysed information from the Internet. Check my findings and draw your own conclusions.
 
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Merlin said:
While waiting to find a more authoritative source of information, this forum thread may be interesting to read: coolthaihouse.com • View topic - Two walls Vs Q-con blocks

As someone living in a 2 storey built using sections of the red-brick method interspersed with standard cement blocks, any other form of construction would be a vast improvement!
Click to expand...

Interesting suggestion to use burnt rice husks as insulation. I would never have thought of that. Easy to get in Surin and free for domestic use. I use loads on my garden.

Family collecting free burnt rice at Surin Biomass power plant:

20200912_034750974_ios.jpg
 
nomad97 said:
To answer the OP, I have analysed the thermal efficiency of 2 different Q-Con walls, one being a single wall built with 20mm thick Q-Con bricks, the other a double wall of 75mm Q-Con bricks with a 50mm sheet of polystyrene sandwiched in between. All information obtained from the Internet and references provided.

View attachment 40202
Reference: https://static-marketing-2.onestockhome.com/attachments/581/qcon_handbook_eng.pdf

From the Q-Con handbook, 20mm bricks have a thermal efficiency of 2.342 against 1.079 for the 75mm brick. So 2 x 75 mm bricks would have a R rating of 2.158 against the 20mm brick's R rating of 2.342.

A 50mm polystyrene sheet has a thermal efficiency (R-Value) of 1.32m2K/W.
Reference: https://www.insulationshop.co/50mm_polystyrene_insulation_boards_eps_70jablite.html

It follows, a double wall of 2 x 75mm Q-Con wall with a 50mm insert of polystyrene sheet would have a thermal efficiency or R rating of 2.158 + 1.32 = 3.478. This is significantly more than a single wall of 20mm Q-Con brick that only offers an R rating of 2.342.

In conclusion, your builder has not done the maths! I believe his advice is incorrect. A double brick wall of 75mm bricks with a 50mm polystyrene sheet in between has an R rating more than 1.6 times higher than a single 20mm wall.

N.B. I am not an expert in this field, I have only analysed information from the Internet. Check my findings and draw your own conclusions.
Click to expand...
Hi Nomad, did you mean 200 mm v's 75 mm?
 
nomad97 said:
To answer the OP, I have analysed the thermal efficiency of 2 different Q-Con walls, one being a single wall built with 20mm thick Q-Con bricks, the other a double wall of 75mm Q-Con bricks with a 50mm sheet of polystyrene sandwiched in between. All information obtained from the Internet and references provided.

View attachment 40202
Reference: https://static-marketing-2.onestockhome.com/attachments/581/qcon_handbook_eng.pdf

From the Q-Con handbook, 20mm bricks have a thermal efficiency of 2.342 against 1.079 for the 75mm brick. So 2 x 75 mm bricks would have a R rating of 2.158 against the 200mm brick's R rating of 2.342.

A 50mm polystyrene sheet has a thermal efficiency (R-Value) of 1.32m2K/W.
Reference: https://www.insulationshop.co/50mm_polystyrene_insulation_boards_eps_70jablite.html

It follows, a double wall of 2 x 75mm Q-Con wall with a 50mm insert of polystyrene sheet would have a thermal efficiency or R rating of 2.158 + 1.32 = 3.478. This is significantly more than a single wall of 200mm Q-Con brick that only offers an R rating of 2.342.

In conclusion, your builder has not done the maths! I believe his advice is incorrect. A double brick wall of 75mm bricks with a 50mm polystyrene sheet in between has an R rating more than 1.6 times higher than a single 200mm wall.

N.B. I am not an expert in this field, I have only analysed information from the Internet. Check my findings and draw your own conclusions.
Click to expand...

You pay for the difference at exactly what cost...materials and additional labor manhours ?
 
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