**Denver Drywall: Altitude AC Hiding Radon Risk?**

By Franklin Everett Shaw

November 10, 2025

The air in your Denver home feels different, doesn’t it? It’s thinner, crisper, and sometimes… drier than you’d expect. But could that dryness, combined with the specific materials used in your home’s construction and your reliance on Altitude AC, be contributing to a hidden danger: elevated radon levels? It’s a question worth asking, and more importantly, answering with concrete action.

Radon is a colorless, odorless, radioactive gas that’s a leading cause of lung cancer. It’s formed from the natural decay of uranium in soil, rock, and water. While radon is present everywhere, certain geological conditions and building materials can cause it to accumulate to dangerous levels inside homes. Denver, with its unique geology and construction history, presents a specific set of challenges.

Could “Denver Drywall,” a term sometimes used to describe drywall installed in older Denver homes, be a factor? And how does Altitude AC, designed to combat the dry climate, play into this equation? Let’s dive into the specifics and equip you with the knowledge to protect your family.

First, let’s address the “Denver Drywall” question. While there isn’t a single, officially recognized product called “Denver Drywall,” the term often refers to drywall installed during specific construction booms in the city. Some older drywall, particularly that imported from China between 2004 and 2008, has been linked to various problems, including emitting sulfurous odors and potentially contributing to corrosion. While the direct link between this specific drywall and radon is not definitively established, it’s crucial to consider all potential sources in older homes.

Now, let’s talk about Altitude AC. These systems are designed to maintain comfortable humidity levels in Denver’s dry climate. However, any HVAC system can inadvertently affect radon levels. By creating negative pressure inside the home, they can draw radon gas from the soil more readily. This is especially true if your home has cracks in the foundation or other entry points.

So, what can you do? Here’s a step-by-step guide for Denver homeowners:

1. Test for Radon: This is the most crucial step. Don’t rely on assumptions. Purchase a radon test kit from a local hardware store or online. These kits typically involve placing a detector in the lowest lived-in level of your home for a specified period (usually 2-7 days). Follow the instructions carefully and send the detector to the lab for analysis. Alternatively, hire a certified radon measurement professional. The Colorado Department of Public Health and Environment (CDPHE) maintains a list of certified professionals.

2. Interpret Your Results: The EPA recommends taking action if your radon level is 4 picocuries per liter (pCi/L) or higher. Even levels between 2 pCi/L and 4 pCi/L warrant consideration of mitigation.

3. Identify Potential “Denver Drywall” Indicators: While not a definitive test, look for these clues, especially in homes built before 2010:

   • Sulfurous Odors: A distinct “rotten egg” smell, particularly noticeable when the AC is running.
   • Corrosion: Premature corrosion of copper wiring, air conditioning coils, or other metal components.
   • Drywall Markings: Check the back of exposed drywall (e.g., during renovations) for markings indicating the manufacturer and date of production. If you find drywall from the suspect period (2004-2008) and originating from China, it’s worth further investigation.

4. Inspect Your Foundation: Walk around the perimeter of your home, both inside and out, looking for cracks in the foundation. Seal any cracks you find with caulk or concrete sealant. Pay special attention to areas where pipes or wires enter the house.

5. Consider Mitigation Strategies Tailored to Altitude AC: If your radon levels are elevated, mitigation is essential. Here are some strategies to consider, keeping in mind your Altitude AC system:

   • Sub-slab Depressurization (SSD): This is the most common and effective radon mitigation technique. It involves installing a pipe through the foundation floor and connecting it to a fan that vents radon gas outside. When installing SSD, ensure the system is properly sealed to prevent air leakage, which can impact the efficiency of your Altitude AC.
   • Sealing and Ventilation: In some cases, sealing cracks and improving ventilation can reduce radon levels. However, this is often not sufficient as a standalone solution, especially with Altitude AC systems potentially creating negative pressure.
   • Heat Recovery Ventilator (HRV) or Energy Recovery Ventilator (ERV): These systems can improve ventilation without significantly impacting energy efficiency. They exchange stale indoor air with fresh outdoor air while recovering heat or energy. This can help reduce radon levels and improve indoor air quality, but consult with a qualified HVAC professional to ensure compatibility with your Altitude AC.

6. Choose a Colorado-Approved Radon Mitigation Contractor: Don’t just hire anyone. The CDPHE maintains a list of certified radon mitigation professionals in Colorado. These contractors have the training and experience to properly install and maintain radon mitigation systems.

7. Maintain Your Altitude AC System: Regular maintenance of your AC system is crucial for both energy efficiency and indoor air quality. Ensure your filters are clean and that the system is properly sealed to prevent air leakage.

Common Mistakes and Pitfalls:

• DIY Mitigation: While DIY radon testing is acceptable, mitigation is best left to professionals. Improperly installed mitigation systems can be ineffective or even increase radon levels.
• Ignoring Low Levels: Even radon levels below 4 pCi/L should be addressed, especially if you have risk factors for lung cancer.
• Failing to Re-test: After mitigation, it’s essential to re-test your home to ensure the system is working effectively.
• Neglecting Maintenance: Radon mitigation systems require periodic maintenance, such as fan replacement.

Real-World Scenario:

Let’s say you live in a 1970s ranch-style home in Aurora, Colorado, with an Altitude AC system. You notice a slight sulfurous odor when the AC is running and decide to test for radon. Your results come back at 5.2 pCi/L. You also find some corrosion on your copper pipes.

In this scenario, you should:

1. Contact a CDPHE-certified radon mitigation contractor.
2. Discuss the possibility of “Denver Drywall” with the contractor.
3. Consider an SSD system tailored to your home’s foundation and AC system.
4. Ensure the system is properly sealed to prevent air leakage.
5. Re-test your home after mitigation to confirm effectiveness.

Protecting your family from radon is a serious matter. By understanding the potential risks associated with “Denver Drywall,” Altitude AC systems, and Denver’s unique environment, you can take proactive steps to ensure a safe and healthy home. Don’t wait – test your home today.