Not only is my house making me sick; it’s not even making me comfortable while it’s making me sick. Let me explain what I mean.
My lovely wife Kathy and I live in a three-level home built in the 1970s. It has forced-air heating (same as the majority of U.S. homes). With five daughters and 16 grandchildren, well…you understand why we haven’t changed it.
It is a well-known fact that all forced-air homes have one thing in common: they all have a blanket on the couch. Why? Because hot air rises, leaving the colder air near the floor. Since hot air rises, you need to get the heat back down to where the couch is. So you install a ceiling fan. Now you have created a draft to get your own heat back.
But wait, it gets worse!
This three-level home of mine has only one thermostat, located strategically in the hallway — where no one lives. Interestingly, my car has three thermostats: one on the driver’s side, one on the passenger’s side and one in the back seat. My house has one; my car has three.
Having only one thermostat in the house causes us to migrate twice a year just like wildebeests. In the summer, it’s too hot to stay upstairs. So, we migrate to the basement. In the winter, it’s too cold to stay in the basement. So, we migrate back upstairs. Just like wildebeests, twice a year we pack up our belongings and migrate.
In the summertime, the air conditioning kicks in. Since cold air sinks, our basement gets so cold that you could swing beef in the family room. Our cat sleeps atop the water heater to keep warm.
Additionally, since all our floors are terrifyingly cold all year, the entire house is carpeted. (I’ll come back to the horror of that in a bit.) Stepping out of the hot shower onto a bare tile floor is an exercise in pain management and mind control. You have to mentally prepare yourself for that first step onto the tile. It makes my knees weak just sitting here typing about it.
(By the way, as a side note, don’t you think the term “forced air” sounds abusive?)
Temperature Realities
Let’s talk temperature. Residential forced-air thermostats are able to measure air temperature only. But air temperature is not the true measurement for comfort. Operative temperature is actually the true measure of comfort.
Operative Temperature = Air Temperature + Mean Radiant Temperature ÷ 2.
Mean radiant temperature is the measurement of the area-weighted temperature of all of the objects that surround the body; e.g., furniture, walls, flooring, etc.
For example, if the mean radiant temperature of your furniture is 62°F, and the air temperature of the room is 70°F, you will feel like it is 66°F, even though the thermostat says 70°F (which is often the case). You will find you must keep the thermostat at 73°F just to be comfortable. I am often uncomfortable because of the mean radiant temperature of the room.
However, temperature alone accounts for only 20 percent of the comfort pie. According to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), other factors contribute to this as well.
Note: If you’re in the heating business, you would be well advised to get yourself a copy of the ASHRAE Standard 55 that covers comfort.
These other factors include: relative humidity, stratification (the difference between the temperature at the floor versus the temperature at the ceiling), asymmetrical temperatures (differences of temperature between one side of a room versus another, or temperatures next to large, plate-glass windows), drafts, odors, fan noise, temperature drift, operative temperature and a host of other less-important factors. Many of these comfort factors are exacerbated by forced-air systems that heat air and move it from room to room using a fan.
Serious Sickness
Now that I’ve covered the “uncomfortable” part, here comes the “making me sick” part. Every human being sheds about 1.5 million dead skin cells every hour. Yes, you heard me right, 1.5 million. Per hour. Where do these dead skin cells go? Into the ductwork and onto the carpeting.
Dust mites produce 200 times their body weight in dust-mite poop over the course of their lifetimes.
You know that foul smell when you first fire up your furnace in the fall? That smell comes from dead skins cells burning on top of the furnace’s heat exchanger. The last time your Uncle Harry was over, it seems he left a couple hundred thousand dead skin cells behind. And that is what you are smelling: Uncle Harry’s dead skin cells cooking on your heat exchanger.
You may be asking, “Doesn’t my furnace filter trap these dead skin cells?” Furnace manufacturers recommend you change your filter every month. That’s probably not going to happen, but let’s just say you actually did change it once a month.
New furnace filters are less effective at filtering than old filters. That seems counterintuitive, but it’s no less true. The older the filter, the more it traps. But the more it traps, the less air flow it allows through, hindering the performance of the furnace and limiting its life span. So if you change the filter every month, you get poor filter performance. If you don’t change it every month, you get poor furnace performance.
Your choice. Either way, the system won’t get most of the dead skin cells that are causing the issue in the first place.
The good news is, you can buy high-efficiency, pleated furnace filters with electrostatic charges that will remove 97 percent of particulates. These can cost upwards of $100 per filter. Replacing these monthly could produce financial ruin.
Fortunately, the dead skin cells that fall into the carpet are quickly eaten by dust mites.
· The good news: Dust mites are really, really small, so you can’t see them.
· The bad news: Dust mites are really, really small, so you can’t see them.
A teaspoon of dust can contain well over 2,000 dust mites. Dust mites are from the arachnid family (spiders), and they eat dead skin cells. On average, 10 square feet of carpeting contains 10,000 dust mites. And then they die. It is not uncommon to find 100,000 dust-mite carcasses decomposing in 10 square feet of carpeting.
Besides their disgusting, decomposing, dead bodies, dust mites produce 200 times their body weight in dust-mite poop over the course of their lifetimes. That’s a lot of poop by anyone’s standards. And their little dust-mite claws ensure 95 percent of them survive regular carpet vacuuming.
Here’s an interesting fact: Carpeting doubles its weight every seven years no matter how much vacuuming is done. Where do you suppose that extra weight comes from?
If you want to spend an afternoon terrifying yourself, go to YouTube and type in: “What’s crawling in my carpet?” You will immediately want to rip all the carpeting from your home. If you are prone to allergies, your allergist will often recommend removing the carpeting as a first step in getting relief.
Now for the bacteria: Philip M. Tierno Jr. has a Ph.D. in microbiology and immunology. He authored a book called “The Secret Life of Germs.” In it, his research shows that your carpet probably contains about 200,000 bacteria per square inch, making it 4,000 times filthier than your toilet seat.
Wait a minute. Isn’t the main reason you have carpeting is because your feet are cold?
Hmm. I wonder if there’s another solution.
The Solution
Many of the indoor air quality problems associated with uncomfortable and sick structures can be solved or greatly minimized by installing radiant heating. First, there is the unsurpassed comfort. My friend and industry colleague Mark Eatherton gave me the best definition of comfort I have ever heard. It goes like this:
“Comfort is not being aware of your environmental surroundings. You are not hot, nor are you cold. Your sinuses are not dry, nor is the humidity too high, and you shouldn’t be able to hear any noises associated with the delivery of your comfort. If you are not thinking about your surroundings, simply stated, you are comfortable.”
Isn’t that great! From a comfort standpoint, radiant heat has the best ability to provide satisfaction in all these scenarios. It provides more even heat in the places where you need it, like at your feet. There are no fans creating noise or moving odors from room to room. (If you’ve ever cooked lutefisk in the kitchen and then tried to sleep in the bedroom, you understand odor movement.)
You can rip the carpets up and have nice, warm hardwood floors that don’t trap dust mites and bacteria. If you’d like to have an area rug where you step out of bed, no problem.
Radiant heating provides a great alternative to sick and uncomfortable living spaces. That’s my take on it, anyway.
Now, you may be thinking, “Well, Steve, don’t you say all of this because you sell radiant heating systems?” Actually, it’s the other way around. I sell radiant systems because I believe in them.
I would be grateful to hear your thoughts, ideas and stories. Until then, best regards and happy heating.
Steve Swanson is the national trainer at Uponor Academy. He actively welcomes reader comments and can be reached at [email protected].