<fort-nav><navclass="fort-nav"data-fort="nav"><ahref="/">Adam Banega</a><ahref="/films/clay-floor/">Index</a><ahref="/clay-floor.html"class="active"aria-current="page">Clay Floor Field Notes</a><ahref="/thermal-mass-lag.html">Thermal Mass & Fan Lag</a></nav></fort-nav>
<p>The clay floor mix was a blend of 60% clay, 30% sand, and 10% straw. This ratio provided the necessary thermal mass while ensuring structural integrity. The clay was sourced locally, and the straw was added to prevent cracking as the floor dried.</p>
<figure>
<imgsrc="https://images.pexels.com/photos/5479520/pexels-photo-5479520.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940"alt="Tomatoes ripening in a greenhouse">
<figcaption>What the floor was for. Heat without mass cooks fruit; heat with mass ripens it.</figcaption>
</figure>
</section>
<section>
<h2>14 July lag log</h2>
<p>On 14 July, we observed an 8-10 minute lag between the heat spike and the exhaust fan trigger at 92°F/33°C. This lag is crucial as it allows the clay floor to absorb the heat, preventing sudden humidity spikes that can damage the plants.</p>
<divclass="callout">The best engineering is invisible. The clay floor does its job quietly, ensuring the greenhouse environment remains stable.</div>
</section>
<section>
<h2>Fan delay</h2>
<p>We used a 140 CFM inline fan with a bimetallic thermostat and a 15-minute time delay relay on the intake. This setup ensured that the fan only activated when necessary, reducing energy consumption and maintaining a consistent environment.</p>
</section>
<section>
<h2>Three failure modes</h2>
<p>1. **Cracking**: If the straw content is too low, the clay floor can crack as it dries. This can be mitigated by ensuring the straw is evenly distributed throughout the mix.</p>
<p>2. **Poor thermal performance**: If the clay content is too low, the floor won't have enough thermal mass to absorb the heat effectively. This can be avoided by sticking to the recommended mix ratios.</p>
<p>3. **Humidity spikes**: If the fan delay is not set correctly, the greenhouse can experience sudden humidity spikes, which can damage the plants. This can be prevented by carefully calibrating the thermostat and time delay relay.</p>
</section>
<section>
<h2>Grounding</h2>
<divclass="fort-box">
<fort-kgquery="greenhouse"><ulclass="fort-kg"data-fort="kg"data-query="greenhouse"><li>greenhouse — building in which plants are grown</li><li>Greenhouse — vehicle component</li><li>Greenhouse — album by Leo Kottke</li><li>Greenhouse — Wikimedia disambiguation page</li><li>Greenhouse — album by Brotherhood of Man</li></ul></fort-kg>
