Years ago, shortly after putting solar panels on my house, I ran some tests to see if cleaning my panels of pollen made a difference. At the time, I found minimal difference in the output of my entire system so I concluded that I didn’t really have to worry about keeping the panels clean. Plus, most of the on-line info I found supported this, stating that rain naturally washes away most of the debris that settles on the panels.
However, this past year, I upgraded my system with solar optimizers. Due to tree growth, my array was having more problems from shading, causing the entire system performance to degrade. Optimizers allow each panel to operate more independently, reducing the negative effect of shading on one panel. In addition, the optimizers were connected to the internet, allowing me to monitor the output of each individual panel. Most modern systems provide this capability. It’s an extremely powerful troubleshooting tool.
As an energy geek, I wanted to see how my panels were performing after installing the optimizers, since I paid a good chunk of change for the upgrade. Sadly, when I compared my system output to past years, I didn’t really see much, if any improvement! Why would this be?
On paper, geothermal, or more accurately, Ground Source Heat Pumps (GSHP), are amazing. They pump out endless heat during the winter and cold during the summer at costs that are often much lower than conventional heat pumps. They don’t pollute (directly). They’re quiet, comfortable and, when properly maintained, should last decades.
But what’s the reality? Are geothermal heat pumps really worth it? Keep reading to learn the answers!
I received an excellent question today, in a nutshell it was: “Why is my house so humid that condensation is dripping from the ceiling?”
The questioner reminded me of all the times I’ve heard this question, both on this blog and when I was in the field, helping track down issues in people’s homes. Clearly this is serious issue that needs more attention because it leads to problems with a home’s health, comfort and efficiency – exactly the things I focus on! (I also wrote extensively on this in a previous article: “Cathedral Ceilings – Mold and Moisture”)
Let’s look at car charging. Consider a Level 2 home car charger. (Wikipedia article on car chargers.) These are the type that wire into your home’s breaker box using a 240V line (in the USA). These charge your car at up to ~7.2 kilo-Watts (7,200 Watts), drawing ~32-40 Amperes of current. (note: for the rest of the article, I’ll use the shorthand notation – ‘V’ for Volts; ‘W’ for Watts; ‘kW’ for kilo-Watts, and ‘A’ for Amperes.)
This sounds like a lot, but how does it compare to other things in your house?
Tongue and groove ceilings – they’re beautiful, but like many beautiful things, they can be problematic.
(Photo shows a thermal scan of a ceiling where cold air is leaking in through the gaps – those are the black streaks down the photo)
Unfortunately, T&G ceilings have become the single most discussed items on Ted’s Energy Tips due to their overwhelming tendency to be associated with water, mold, or moisture problems.
Does your ceiling drip water?
I’ve probably heard this a hundred times – “Help! Water is leaking from my ceiling! We had a cold snap and now it’s a beautiful day and now it’s raining in my house!” The caller/writer then tells me that the roofer came out to check for leaks and couldn’t find anything. If they took it a step further, someone pulled off some of the ceiling planks, saw the real problem (condensation) and told them that they need to ventilate the ceilings. If they’re unlucky, they spent thousands of dollars, added ventilation, and the water problems became worse!
Why do ceilings drip when there’s no leak?
Boil a pot of water with a lid on it. Wait a minute then lift the lid. What do you see? Lots of water on the underside of the lid. There’s no ‘leak’ but yet the lid is covered with water due to condensation forming on it. This is exactly what’s happening inside your ceiling. Under the right conditions, when water vapor in the air comes in contact with a surface cooler than the air, the water vapor becomes liquid water. If this happens enough, the water builds up and forms large drop of water. Those get large enough and, PLOP!, it starts raining in your house!
All too often, a T&G ceiling is constructed in a way that virtually guarantees water problems. The roof is installed over the rafters. Fiberglass is shoved between the rafters. T&G boards are nailed to the rafters. Bingo – you get mold, water “leaks”, and thousands of dollars of repairs which probably don’t even fix the problem.
Why don’t normal ceilings drip?
A typical ceiling is made of sheetrock or plaster, and all the seams are carefully filled in. That’s then painted, usually with several coats of paint. While some tiny amount of water vapor can get through the paint and sheetrock, it’s a very small quantity. Small enough that, under normal conditions, natural air flow and moisture transfer removes the moisture that does get into the ceiling cavity above the sheetrock.
However, even these ceilings often have problems when holes are cut in them for recessed lights. This allows that air and moisture to move much more quickly into the ceiling where it can condense and lead to mold growth and wood rot. The key fact – if air gets into your ceiling, even through small holes, it will carry water vapor with it which is very likely to lead to moisture problems.
Why are T&G ceilings so bad?
Water vapor is tiny. Really, really tiny. So tiny, that even the smallest crack is billions and billions of times larger than the water molecule. Tongue and groove ceilings may look ‘tight’ but to a water molecule, it’s like a wide open door! So that water vapor simply flows right up through those cracks and into the ceiling cavity above.
To Make matters worse, most ceilings are stuffed with fiberglass insulation, which doesn’t stop the water vapor at all. So the vapor keeps wafting up past the insulation until it reaches the underside of your roof. That roof deck is cold in the winter and on clear nights. When the vapor hits it, it condenses into liquid water. This is when the real problems start…
When it’s below freezing, the water freezes into ice. More water vapor enters, contacts the ice, and adds to the ice. Before you know it, the entire underside of the roof and anything else cold enough in the ceiling cavity, is covered with a layer of ice. This could go on for days, weeks or even months until the ice melts and it starts raining in your living room!
Even when it’s not below freezing, in most climates, it gets cold enough and there’s enough water vapor carried by the air for condensation to form inside the ceiling. The wood can absorb some of that moisture and slowly transfer it out. But with a T&G ceiling, the water supply inside the house is nearly infinite, so it keeps building up. Pretty soon, the wood is saturated and larger water droplets form. They’ll drip down, following gravity, until they find a place to leak out. That’s why the drips often form far away from where the condensation is actually occurring, which is often high up the ceiling.
Will ventilation solve the problem?
Builders are taught that roofs have to be ventilated in order to ‘flush out’ the moisture. The problem is, that doesn’t work with T&G ceilings. In fact, it often makes problems worse.
Why? As the air moves through the cavity, it has a tendency to draw more air from the inside of the house into the cavity. Some of that is flushed out with the air moving through the cavity. But when the water vapor carried by the air comes in contact with cold surfaces, it basically sticks. If there’s enough, which there usually is in a house during winter, then you still have the condensation problem.
How do you prevent water vapor from getting in the ceiling?
Take a step back. What ceilings work properly? We started discussing how a typical drywall ceiling usually doesn’t have moisture problems like these (unless you put holes in it). So the easiest solution is to build a normal drywall ceiling over which you install the T&G boards – purely for aesthetic purposes. Drywall is cheap. Replacing your roof is expensive.
What about plastic sheeting?
Drywall is cheap. Replacing your roof is expensive. Some builders try to ‘cheap out’ by just putting plastic up, usually with thousands of staples, then nailing the T&G boards to the rafters, with thousands more nails. Do you think a sheet of plastic with thousands of holes in it is going to stop the movement of water vapor, one of the tiniest molecules in nature, from getting into the ceiling? Maybe it will take 5 years to rot out the roof instead of 3. But eventually, you’re going to be spending many thousands of dollars for a new roof, just because the builder decided to take the cheap approach and save a little bit of drywall.
Ok, Ted, how would you build a T&G ceiling?
Glad you asked. Here’s how I did it when we replaced our sunroom. We used high density spray foam. The foam completely fills the rafter bays, as in the photo above. Any remaining cracks are caulked. Then we installed the T&G ceiling to the rafters, like in the photo below:
We’ve had this ceiling for more than 10 years now with zero issues. It’s on the kitchen which gets humid from cooking, but still, no problems.
Would you do it differently if you did it again?
Good question! I might add a thin sheet of foil faced polyiso sheet foam across the rafters before installing the T&G ceiling to add another layer of moisture barrier and to reduce thermal bridging through the wooden rafters. In extremely cold climates, this would be highly recommended as you could still get condensation on the exposed rafters because they transmit the cold much more than the insulation. But in eastern PA where I live, it’s not cold enough to warrant that extra work for the minimal gain given this construction.
I already installed my ceiling, can I seal the wood or the seams?
In a word – no. That might slow the process slightly, but eventually you’re going to regret the decision when your roof rots out and your ceiling is filled with mold. Shortcuts don’t work with T&G ceilings. You have to do them right, or you’ll pay the price eventually.
Can I install recessed lights in a T&G ceiling?
If you’ve read much on this, or any other energy efficiency and building science website, you’ll know that recessed lights are nightmares. Yes, they look clean and some are even rated ‘air tight’, but those ratings are BS. They are filled with holes which let ample moisture through. That moisture will go into your ceiling and cause the same issues.
The compromise I’ll make is if you do a full foam job like I did and then install low-profile LED lights that don’t require reducing the insulation. Since the T&G ceiling isn’t an air barrier anyway, cutting holes in it to mount these lights doesn’t matter. The low profile LED lights look just like normal recessed lights but they don’t protrude into the ceiling cavity. Here’s an example of a ‘canless’ recessed light at Home Depot.
For the last few years, I’ve been closely (Evy would say “obsessively”) following the electric vehicle (EV) market, waiting for the “perfect” car. I wanted something compact yet spacious enough to haul my bike or golf clubs. It had to have good range, preferably enough so I could use it with only a single recharge when visiting my folks on Cape Cod. It should be comfortable. It couldn’t cost a fortune. Easy, right?
I had been driving a Volkswagen e-Golf for the last couple years. A friend wasn’t using hers, so I took over her lease. I liked the e-Golf a lot, and would have bought it IF it had more range. But this was one of the early models with under 100 miles of range under the best of conditions, so it was unsuitable for road trips. That was fine, as 99% of the time, I’m only driving locally and could use Evy’s car for road trips.
But the time had come for me to get my own car. The Kia Niro EV looks like the perfect car for me. It is exactly the right size, has a range of about 250 miles. Supports fast charging for road trips. It looks sharp. Has a ton of cargo space and is priced competitively. BUT, it wasn’t yet on the market, and I wasn’t willing to wait for it to come to Pennsylvania. Scratch that off my list, darn it!
The Hyundai Kona Electric, the sibling of the Kia Niro was my second choice. It’s smaller than the Niro but still has ample cargo capacity. Since it shares the drive-train with the Niro, it’s peppy and has even more range (since it’s smaller). It’s similarly priced (mid $30’s before $7500 tax incentive). But again, it isn’t available widely yet. Plus, dealers have been marking it up well above MSRP, and I refuse to support price gouging. So back to the drawing board.
Then Tesla announced the Model Y, their compact SUV. The Model Y checks all the boxes for me except it’s a little larger than I wanted. It’s also more expensive. But it looks like a great vehicle. It has a range of up to 300 miles. Since it will use the Tesla supercharger network, there are plenty of charging stations along the i95 corridor, so I could drive anywhere around here conveniently. A big plus is it’s available in an AWD version, which is a big plus for Evy, who is a Subaru AWD die-hard. Even better, Tesla’s (poorly named) auto-pilot feature and top safety ratings make it desirable for longer trips. Finally, Tesla has a big head start on all the other car manufacturers so their cars are several generations ahead. Unfortunately, the Model Y won’t be on the market for a couple of years (at least!) Darn you Tesla for teasing me so!
Because I really wanted to get a car ASAP, I starting looking at used vehicles. I knew I didn’t want another first generation EV because their ranges were too short. A used Tesla was too expensive. What to do? What to do?
After doing a lot of research, and checking used car prices, I decided that the Chevy Volt was the vehicle for me. Here’s why:
It runs ~50 miles on batteries alone, making it perfect for local travel.- As a hybrid, it has unlimited range (just like a regular hybrid) and gets good gas mileage (42 mpg) making it suitable for road trips.
It’s compact without being tiny.
You can buy used 2nd generation (2016-) with low mileage for around $20,000
It has decent cargo space with the rear seats folded down.
It’s comfortable as long as you don’t sit in the rear seats!
As luck would have it, a local Chevy dealer had a spotless Volt with modest miles on the odometer. They were selling it for a good price so I grabbed it.
I should note that Chevy recently announced that they were discontinuing the Volt, so I think dealers are moving them off their lots. Who wants a discontinued car? Me!
Why is the Chevy Volt Much Better than a Conventional Hybrid?
The first thing people ask is: “why not get a plug-in Prius or other plug-in hybrid? The answer is, basically, they suck as electric cars. Every other plug-in hybrid uses it’s gasoline engine at the same time as the electric motors in order to generate a useful amount of power. They were designed as conventional hybrids where the gas engine always runs. When they converted them to plug-in hybrids, which are just hybrids with larger batteries and a mode that turns off the gas engine, they neglected to give them powerful enough electric motors. These things are downright pokey in electric only range!
The Chevy Volt is what’s called a “serial hybrid.” Instead of using the gas engine to power the wheels directly, it’s used only to generate electricity to charge the batteries. The batteries, in turn, power the electric motors. The generator (gas engine) can also feed electricity directly to the motors. The electric motor is the primary drive and has to be powerful enough to do the job of accelerating up to highway speeds and pass safely. The Volt does this admirably. And, while it’s no Tesla, it leaves all the plug-in hybrids in the dust.
The downside is that it still has a gas engine, so the system lacks the utter simplicity of a completely electric car. But for $20,000, it’s a great vehicle. It’s been on the market for a number of years, so Chevy dealers know how to service it. And, as the battery capacity diminishes over time (they all do), it will still be useful because the battery is much larger than a conventional hybrid.
Is the Chevy Volt perfect? No, but no car is. The rear seats are definitely “child sized.” They have decent legroom but the headroom is pathetic. Evy whacked her head on the roof as she entered the rear seat. Ouch! The cargo space with the rear seats up is enough for groceries, but not big enough for my golf clubs, so mostly I drive with the seats folded down, figuring no passenger would want to sit back there anyway! Acceleration, while good (~8 seconds), is not blistering. But I’m not a motor-head, so that doesn’t bother me. It’s at least as good as other cars I’ve driven. But acceleration fanatics will find it lacking. Hybrid gas mileage could be better. Modern hybrids are getting more than 50mph, so the Volt’s 41mpg seems low. I won’t know the “real” mileage until I take a road trip since I drive it 100% on electricity now (infinite MPG!!!) I’ll report back after my first trip.
Overall, the Chevy Volt is a great “gateway” vehicle. It runs very nicely in electric mode, but you have none of the “range anxiety” you have with other electric cars. You just drive it normally and burn no fuel. Until you drain the batteries and the gas engine kicks in. This type of every-day normalcy makes it ideal for those who are looking at having a very eco-friendly vehicle without worrying about “will I get there?” And at their current used-car prices, they’re a “best buy” that I’d recommend for anybody looking to test the electric car waters.