I'm living in a four-story townhouse with two separate AC systems, but I'm struggling with humidity on the top floors, even while the ACs are running. We've made several modifications to improve insulation and energy efficiency, but now the upper levels are too airtight, causing humidity to build up because the AC doesn't activate often enough. At nighttime, setting the AC to a lower temperature helps, but I need a more consistent solution during the day. I've been advised by an HVAC technician that there are no options for a whole house dehumidifier due to space constraints near the blower unit, which measures around 36"L x 80"H at the widest point of the roof slope. I'm tired of using noisy portable dehumidifiers that need frequent emptying and add extra heat to the house. Are there any compact whole-house dehumidifier options that could be installed in the limited space, or alternatives that can connect to my existing duct system?
2 Answers
You might want to look for a high-capacity dehumidifier measured in pints per day instead of just focusing on square footage. I saw some 15-gallon per day models on Amazon for around $280. They can be effective if positioned near your air handler to help circulate air. Plus, if you're able to get to the drain pipe, you can set it up to drain directly instead of emptying a bucket all the time, which makes it more manageable. Another temporary option could be cranking your AC to the lowest setting so it'll run continuously, just be prepared for it to feel super cold!
I checked your photos, and it looks like the layout of your HVAC could accommodate a whole house dehumidifier with the right installation. You can install one in various configurations, and there are options where it's not integrated into the system, although that might create some issues with airflow and duct temperatures. Small models like the Santa Fe Ultra 70 or AprilAire E070 are compact—about 12x12x28 inches—which could work in your tight space. Just make sure to consider the installation space and the air circulation to save yourself from extra heat issues!
Yeah, I see your point. The space behind the air handler seems tricky. Maybe there's a chance for a stand-alone system that could work better?
But I’m really curious about the setup. I'm not sure how to install a dehumidifier in that closet with all the ductwork in the way. Would a small unit even fit there?