I like the stand alone dehumidifers better than ones incorprated in to hvac system. When you place the dehumidiferes in the conditioned space they sense the RH in that space, many central dehumidifiers sense the RH in the area they are located in and do not dehumidify the conditioned space as well. Where are you located? Where are central units located? Have you talked to hvac company about adjusting dip switch settings? Many times they are installed with factory settings and need to be adjusted for your climate. ERV's are usually not for cold climates..that would be an HRV, so I wonder about your location. Also ERV's are for 'tight' houses..with less than .25 air changes per hour. If your house is not at this level of air tightness the ERV can bring in moisture adding to the dehumidification load of hvac. Was the house tested for air tightness with a blower door? To 'see' what is happening behind the walls and between floors of your home would require a thermal scan of your home. This will show you moisture intrustion sites and moisture in walls, ceilings and floors. IMO this will be the way to go to actually KNOW what is happening. Then whatever the IR scan shows will be on you to address. Around here (Louisiana) thermal scan (InfraRed) scans are used often when home owners and builders are seeking solutions. I've even seen them used in court cases. But hopefully...it won't come to that! best of luck.

Thanks to everyone who have replied with suggestions. I did figure it out and it's all quite embarassing! I read on the internet that sometimes a dead animal smell can sometimes be confused with burning electrical wires. I smelled my daughters light switch in her bathroom and oila! Boy was it strong. There was also an electrical outlet close to the smell in the kitchen so, I called the electrician...But wait, it gets better! Electrician came out. Said it wasn't electrical wires, more like a chemical or hair burning. Took him about 30 minutes, but he figured it out. I had purchased some strong kind of glue to fix my daughter's shoes. The glue was sealed up, but sitting on my counter in the kitchen. My daughter's shoes were in her closet (therefore the smell in the bedroom) and my handyman had used to glue to fix the lightswitch he had cracked in my daughter's bathroom. Threw out the glue, the shoes, and the lightswitch. Mystery solved!

I'm with karateken123, I'd love to know if mama_mia really did resolve the odor problem she wrote about in 2010. What she is describing sounds exactly like what I have been fighting in a small house I bought in June 2015 (still haven't moved in.) My odor also defies all normal description and typical odor causes. I've tried lots of things and I've had a dozen experts from various fields in and no one knows what it is. I had some success with an ozone treatment, but the odor was back in a few weeks. I thought that humidity and/or heat hitting the house made it worse, but since it is cooling off now, and the odor has been steadily bad anyway, I am starting to suspect that the amount of wind might be a variable that causes the strength of the odor to fluctuate and not heat or humidity. My situation is a little different from mama_mia because my house is a slab-on-grade, so no crawl space, and the odor is strongest on the south facing side of the house, where my front door/vestibule and kitchen are situated, but it does either carry to or exist in the other rooms of the house-just not as strong. Please, don't reply if you have only the typical recommendations--this problem defies all normal solutions and I've been working on it and researching for months. Unless you have something that is NOT typical to suggest, then you can be sure I've thought of it/tried it.

I have lived in... A cheap Michigan home on a slab that I don't remember well, but my mom said it had ants, "They built it on an anthill." An old MI farmhouse on a dirt-floored smelly basement. Smelled like mice. Our furnace, water heater, and oil tank were down there and when a storm came that threatened to turn into a tornado, none of us kids would go down there because none of us could find our shoes. We were barefoot all summer unless we were going to town with a parent. An 1955 NJ ranch home on a dry basement that had a noisy sub pump that came on when it rained. A 1955 Baton Rouge ranch-style house with large overhangs and no gutters. "Gutters don't work down here," we were told. The rain came so fast that the gutters would have overflowed. Insisted on a pier-and-beam construction on this house because I knew that my knees would not allow me to stand or walk for long on concrete. When I was 13 I played the role of a runner for my great aunt at a ceramic show, and was on my crutches again for a week afterward. So we only looked at old houses in BR. In town, all the newer houses were on slabs. Our house smelled musty some times. Then we learned that the guest bathtub drained to the ground under the house! My 1950 MI house on Chippewa had a basement that was too humid. That had to do with the gutters. They were no good - rusted and not leveled right. They leaked like crazy above the front door. The front porch was wood. But all the identical houses in the neighborhood had concrete porches. Turns out there was a root cellar (like a closet with a dirt floor and concrete walls and top that is "outside" the basement - a door in the basement wall opens up to this dirt-floored closet. It stays cooler than the rest of the basement. Turns out that the concrete porch is the top of the "root cellar" and when somebody took it out, they took out the roof of the cellar! Smart-a$$ then used plywood to make a "ceiling" to the root cellar. Plywood under dirt that is above the cellar. By the time I bought the house, it was rotted. When it rained, a flood of water from the roof went onto the porch because of the improper slant of the gutter. Stream of water went to root cellar, then across the basement floor to the floor drain near the furnace and water heater! I had my own little river in the basement. New concrete porch fixed that snafu! Still needed dehumidification. Our current 1978 house (goodby 1950s!)has a dry concrete basement with a sump pump. Smells fine. At the front of the house, the garage, laundry room, foyer, and living room are all on a slab. There are cracks in the corners of some walls due to uneven settling of the slab. The previous owner spent several thousand dollars on "Ram Jacks" TM to stabilize the living room. That is my tour through the basements of my life!