Understanding Terminology
Summertime Overheating
Jun
With the UK coming to the end of another Extreme Heat Warning, and summer temperatures continuing to rise over the years, overheating is becoming one of the biggest challenges facing designers, contractors and homeowners.
For years, the focus has rightly been on keeping heat inside our buildings during the winter. However, the industry now needs to give equal consideration to summertime overheating (Part O) as it does to achieving ever lower U-values.
This is where natural insulation products come into their own.
Pavatex Woodfibre insulation not only delivers excellent thermal performance in winter but also provides outstanding protection against summer heat. One of the key reasons is its density and heat storage capacity.
|
Product |
Typical Density (kg/m³) |
Heat Storage Capacity (kJ/m³K) |
Summer Heat Protection |
|
Glass Mineral Wool Batt |
15 – 35 |
13 – 29 |
⭐ |
|
Stone Mineral Wool Batt |
35 – 70 |
29 – 59 |
⭐⭐ |
|
PIR Insulation Board |
30 – 40 |
42 – 56 |
⭐⭐ |
|
Pavaflex |
50 – 55 |
116 |
⭐⭐⭐⭐ |
|
Isolair Multi |
145 – 200 |
305 – 420 |
⭐⭐⭐⭐⭐ |
|
|
|
|
|
What is Heat Storage Capacity?
Heat Storage Capacity is a measure of how much heat an insulation material can absorb and temporarily store before it passes through the building fabric. In general, the higher the value, the longer it can help delay heat entering the building, improving comfort during hot weather.
Heat Storage Capacity values are calculated using typical published densities and specific heat capacities for commonly available insulation products. Actual summer performance depends on the complete wall or roof build-up, including insulation thickness, construction, shading, glazing, ventilation, and airtightness.
Unlike many conventional insulation materials, woodfibre has a much higher density and a significantly greater ability to store heat than many conventional insulation materials, including PIR insulation. Rather than allowing heat from the sun to pass quickly through the building fabric, it slows heat transfer, helping to keep internal spaces cooler during the hottest parts of the day.
The benefits include:
• Improved summer comfort
• Reduced reliance on air conditioning
• Lower energy costs
• Better year-round thermal performance
• A breathable, natural insulation solution
As our climate changes, designing for summer performance is no longer a luxury, it’s becoming essential.
Choosing insulation is no longer just about achieving the lowest U-value. It’s about creating buildings that are comfortable, healthy and energy-efficient in every season.
How are you addressing summertime overheating in your projects?
