Hemplime
An optional hemplime wall for data centers that want less heat from the sun, steadier humidity and less noise. It fits a new build or an existing site. BioVerdi SAS offers it as an add-on, not as part of every build.
What it is
Hemplime is the woody core of the hemp plant, mixed with lime and water. It carries no load, so it is cast around a frame. A model residential code treats it as wall infill.
Most data centers are built from steel or precast concrete. The hemplime wall goes inside that structure; it does not replace it.
Microsoft builds first datacenters with wood to slash carbon emissions. Microsoft Source, 2024.
New builds and existing sites
In a new build, the wall is cast inside the steel shell. In an existing data center, a hemp-clay plaster about 6 cm thick can be trowelled onto the walls; the study found it adds insulation and blocks more sound.
Cooling
Heat moves slowly through it: tested samples conduct 0.087 to 0.10 W/m·K. It also takes in and gives back moisture, which keeps indoor humidity steadier.
The servers make most of the heat. In one study, 19.5% of a data center's cooling load came through the walls and roof, in a cold region. How much a wall changes that share depends on the climate, so we model it per site. It does not cool the racks.
Noise
Hemplime soaks up sound. Bare samples absorbed 40 to 50% of incoming sound on average.
Light mixes absorb 60 to 100% of sound at their peak, between 500 and 1,200 Hz. Dense mixes block more: in a hemp-clay mix, a 4 cm layer at 821 kg/m³ cut sound by 30 dB.
The wall we build
A steel shell outside, a hemplime wall inside and an air gap between them. Warm air rises out of the gap and takes the sun's heat with it. We add fans only for the hours when the air does not move on its own.
Two walls with a gap block more noise than one. A double wall has one weak spot, usually between 60 and 100 Hz, so the gap is sized for each site.
Carbon
Hemp takes in carbon as it grows. Producer figures cited by ASTM put the carbon dioxide held in hemplime at 108 to 165 kg per cubic metre.
Hunt, Green Building With Hempcrete. ASTM Standardization News, 2020.
Cost
We do not claim hemplime is cheaper to build. We found no reviewed study that gives a reliable price. The saving is the heat and noise the wall keeps out and the carbon it holds.
Tell us what you are building.
Send the load, the site and the timeline you have so far. A rough sketch is enough to start, and we will come back with a configuration.
Talk to us