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I started this post early this year after our area had some low temps that hadn't been seen here in probably decades. By the time I was near completion with the post the weather had moderated a bit and this post didn't seem so timely . . .and was abandoned. This wasn't the one I was going to work on today, but if you check the forecast for most of the nation for the next several days . . .this post has become timely again and I decided to update and post!
There's a problem that plagued many a citizen in my area last winter: Ridiculously high electric bills. I suspect it wasn't just around here, but also in many other parts of the South. You had this problem? You infuriated by it? Read on, my friend. Learn why it wasn't the electric company's fault and what you can do to try to avoid a repeat in the future. This is rather a long read, but if it helps lower your electric bill a bit . . .it should be worth it.
I should start off by making it clear that I am NOT an energy efficiency or building science expert. I probably know more than the average Joe, but I sure don't know it all. I'm going to share what I do know and give my own personal and professional opinions in the hopes I can help some folks understand what's going on and why and hopefully help them out for the future. If you're very concerned about it and want to be proactive, I suggest you hire a professional to come do an energy audit on your home. Each home is different, and while I can give some general advice, there's no way I can give advice specific to each home without seeing it in person or learning more about it. This isn't exactly a service I offer anyway, because that's not my area of expertise. My clients will be the first to tell you I will share what I DO know, and also let you know what I DON'T know. I'm all about finding someone who does that and letting them do their job. If you want to learn what I know . . .carry on reading . . .
I really feel like there are two main culprits that end up causing this issue. One is the equipment that's commonly used to heat and cool homes in the south. The other is the entire building envelope.
We'll start with the equipment. The vast majority of homes in the south use a conventional heat pump to both heat and cool their homes. When you live in an area that has fairly moderate temperatures most of the year, these heat pumps work great. Until they don't. When do they not? In extreme temps. They're not really designed to work well when the temperature outside falls below freezing. I don't have an exact number for the summertime, but I really feel they don't work as well when you get into the upper 90s and over 100. But I will say, I feel the heat pump is more to blame in the winter, and the other issue (that I'm about to get to) is more to blame in the summer.
To fully understand this you have to understand how a conventional heat pump works. I'm not going to explain that, but the short version is that a heat pump is heating or cooling air from the outside temperature. (If you really want to understand this, simply search online for how a heat pump works. You'll find all sorts of info to better explain.) So if the outside temp is 82 and it's too warm for your tastes because you prefer a consistent 72 degrees, then your heat pump will cool the air in your home down 72 degrees, but it will be cooling the air from 82 degrees. Easy peasy. Same in the winter. 56 out? No problem. Warming up air from 56 to 72 is too easy. However, when it's a bit colder out . . .say 30? That pump is going to have to work a lot harder because there's a much bigger change in temp. What if it's 9 degrees out? It just can't really keep up. There's a vast difference between 9 degree air and 72 degree air. The cards are just stacked against the machine in this instance.
So what happens? The heat pump will just run and run and run and never really get the home to the desired temperature because it's trying to achieve the impossible. This is also really hard on it since heat pumps should run a long on cycle then a long off cycle. If your heat pump is coming on and off really often and running short cycles that's a sign of a problem. If it's running constantly and never kicking off that means it's likely not able to do it's job. If that's the case, you can refer to a previous post of mine about something you can do in that situation to help keep your house warm. It's a temporary fix, but it's one that's helped me out in the past.
I should mention that the situations I'm describing above are considering a home that uses a conventional heat pump as it's only source of heating and cooling. If you supplement with a fireplace, wood burning stove, or other method of heating it will greatly reduce stress on your heat pump. I know a lot of people who simply use their heat pump to take the chill off in the Spring and Fall while the temperature is fluctuating. Arkansas is known for its unpredictable weather, including drastic swings in temperature. A heat pump switches so easily back and forth between heat and A/C that it works extremely well during these times. However, when winter finally settles in, they'll switch over to using wood (or something else) for heat. A pretty smart system in my opinion.
While not affecting the temperature, but worth mentioning . . .heat pumps also dehumidify the air. Humidity has a lot to do with comfort levels so that's a pretty big deal when you live in an area with consistently high humidity levels. So they're great for multiple reasons, but conventional units just aren't my top choice of recommendations for the reasons above. What is? I'll get to that. Keep on reading . . .
So the building envelope and the systems . . . What's that all about? Well, basically your problems aren't usually caused by one culprit. When people use a conventional heat pump as their only source of heating and cooling their home and they have a problem, they inevitably blame the heat pump. My house isn't staying warm or cool enough, so there must be a problem with the heat pump right? Wrong. Well, sometimes there definitely IS something wrong with it, but I've seen time and time again where the heat pump is blamed, but the machine checks out to be perfectly fine. I've also seen many times where folks think they must have been ripped off and want to spend another chunk of change to get a second opinion because that first one must have been wrong. Right? Wrong!
If it's 106 degrees outside during the day and it's cooling off into maybe the 80s during the night and it's staying this way for some time and your house isn't cooling off properly and you've had someone look at your heat pump and they say it's fine and you don't believe them . . .queen of run ons, I know. Well, it's not the heat pump. And it's probably not necessarily any one other thing in particular. It's probably a host of issues working together to create a bit of an energy disaster.
Take this imaginary house for example: There's a heat advisory for several days. Your house was built in the 70s or 80s and you've never redone any insulation, because they did that when they built the house right? You also have no trees on the west side of your home. Maybe you or someone else cut them down to get a better sunset view? Or maybe there just aren't any there. This house still has the original aluminum windows or maybe had new vinyl windows put in at some point, but the cheapest ones available were used. The doors are a bit bowed and air flow can easily be felt around them with the slightest breeze. So your A/C is running 24/7 and it's still 84 degrees in your house. The unit must be malfunctioning, right? Not really. This is a terrible energy efficiency set-up . . .with a terrible building envelope.
The ENTIRE building envelope and systems need to work together and they all are an important piece of the puzzle. Your structure, your insulation, your windows, your doors, your heating and cooling systems, your sun exposure, your orientation to the sun, your surface area covered with windows, their proximity to the sun. And yes, trees. Shade.
This isn't just for the summer . . .this all holds true for the winter as well. Warm air will ALWAYS be searching for a way to cold. After all there's "no such thing" as cold. Cold is simply a lack of heat, and the heat is always trying to disperse itself. I know that sounds sciency and I'm sure someone with more education in that area can explain that in more scientific terms, but I'm just speaking from common sense. In the winter the heat is trying to get out and you're trying to keep it in. In the summer the heat is trying to get in and you're trying to keep it out. Simple as that.
Furthermore, the more heat you have in the summer to deal with, the harder it is to "keep it out" and keep your home cool. If you've got a big shade tree on the western side of your home, it's going to shade your house, and more importantly, your roof when the afternoon sun is beating down during the hottest part of the day. This is going to keep the house cooler to begin with, giving your heat pump a helping hand.
Each one of the things I listed above plays a part. Some of the things I recommend to my clients when they're building:
Go with 2x6 exterior walls. This gives you a couple extra inches of thickness for insulation in your walls. Not to mention it makes your house just a little bit stronger AND your door and window jams will be a little bit thicker. That's mostly an aesthetic thing, but it's also a mental security thing. I think we as humans feel safer with thicker walls. We can get into all other sorts of depths, but I'm talking about a typical stick framed home here where your options are basically 2x4 or 2x6 exterior walls. What I recommend to my clients is 2x6 exterior walls, and 2x4 walls for all interior except for the special places we need 2x6 for plumbing.
Invest in absolutely the best insulation you can at the time. If you're going to stretch yourself somewhere, this is an area to do it. It's 2018 and right now the best thing I recommend is spray foam. I recommend spraying at the building envelope, so even if you have an attic, that means spray it on the underside of your roof decking. This also creates a nice tight seal on the home and a partially conditioned attic. If you can afford to do spray foam for the entire house, please do. You won't regret it. But if cost is a major issue, then go for the roof. The roof is the most important place to have the best insulation because it's got the most exposure to the sun. So if you need to save a bit, go ahead and spray the roof and then do cellulose in the walls. That's also not a bad choice. If the only thing you can afford is fiberglass batts, then that's sure better than nothing. But absolutely not my top choice and certainly not the most energy efficient choice. If you live in a different area you may have a slew of other options available. Do your homework and ask a lot of questions. But my basic point is invest in the absolute best option available at the time. You don't want to go mid-grade when you can afford better and 3 years later be at the bottom of the totem pole. Invest in best!!
Be smart about doors and windows. Honestly, I've talked with my window guy about this. Some folks get really hung up over the numbers on the windows. If you're doing this, I suggest you REALLY research a lot and know your stuff. Sometimes you can pay a lot more money for a smidgen of extra "number" and it doesn't really do a lick of good. Wasted money. There are absolutely some pretty efficient windows and doors out there these days, but SHOP AROUND. You're going to pay for the good stuff. With building, like many other things, you get what you pay for. The bigger consideration with your windows is going to be the surface area they cover. If you have a wall full of windows, no matter what kind of windows you put in there, they will absolutely never be as energy efficient as the wall surface. So balance young Jedi. Consider the location, the sun, whether you'll use drapes, if you're taking advantage of thermal massing (a topic for another day folks), and any number of variables. To get really efficient windows you're going to be looking at triple panes and they're not going to be cheap. Worth it? Probably so, when you see your electric bills later on.
Having a good designer who considers energy efficiency can help with this. Also, having a home custom designed for your site will make a big difference. Again, you get what you pay for.
And yes, I discuss windows with my clients. They make such a huge impact on your home in many ways. We try to select the exact windows we'll use. And I don't just mean size. I mean manufacturer, model, size, all the specifics. The more specific the better. It's just one of many benefits you get when you invest a bit more in your plans and design on the front end.
Geothermal heat pumps. Yeah, I said I'd get to what my recommendation is. I cannot speak highly enough of geothermal heat pumps. I've told many a client and also many a friend or random person asking my advice: Seriously, the ONLY negative I can think of is that they're expensive. That's it. But I also feel they're worth the additional expense. Geothermal heat pumps function very much like a conventional heat pump, with one major exception. Instead of an exterior unit that is adjusting air temps from the exterior temperature these systems use ground loops. Ground loops are a system of pipes/tubing that run underground with water running through them. The temperature is pulled from this constant. So instead of adjusting from a constantly fluctuating temperature, they're adjusting a temperature from a relatively constant one. In most places, once you get 6' or so below the surface the ground temperature is a constant 56 degrees. Give or take a bit depending on the location. Ground loops can be done several ways, but probably the most common is simply to have wells drilled. The amount of tubing depends on the size/load of the system. This is all calculated and the length determined. The depth and number of wells is derived from that number.
Geothermal heat pumps are insanely more energy efficient than conventional heat pumps. I have three in my home. My home is on a small footprint, but has three levels. It's zoned by level, which means each floor has it's own unit that is independently controlled. A great way to zone, since heat rises and the temperature can vary widely from floor to floor depending on the time of the year. Each one of my geo units only requires a 30 amp breaker and draws only about 7-9 amps while running. A conventional heat pump, by comparison, requires a 100 amp breaker. (At least that was true when I built several years ago) That alone sends an important message about energy consumption.
My units will keep any floor on my home at any temperature I want and sustain it. If it's 9 degrees outside and I want it 74 inside, I can easily keep it at 74. Same thing in the summer. 106 out? Want it 66 inside? Sure thing, no problem. Part of that is the building envelope, and part of that is the machine. I don't have the most energy efficient windows and doors. I don't even have spray foam insulation. I have cellulose in my walls and my top floor has fully vaulted ceilings. The roof is an un-vented roof assembly with dense packed cellulose. I will probably end up pulling that out someday and spray foaming the roof, but that will be part of a larger project if I do. And who knows, by the time I get around to that there may be more efficient options available.
One lovely bonus with geothermal heat pumps is you get free hot water in the summer! How's that work? Honestly, I'm more of a designer than a scientist so I don't know exactly how that works, but it has something to do with the excess heat being pulled out of the air when the A/C is running. It can simply be hooked up to your water heater (conventional tank water heater that is) and the water heater doesn't even need to "click on" and use electricity to heat the water. It's just magically hot. I'll leave it at that.
At the time of this writing, there are also still tax credit incentives for geothermal heat pump expenses. At the time we built our home, I priced out conventional units as well. The most efficient system I could obtain at the time was certainly less expensive than the geothermal system. However, when you factored in the tax credit, it made the cost almost the same. It was absolutely no question for us.
The tax credits are something that you'll need to check into over time, but here are a couple of links that share info at the time of this writing:
Existing Homes. So those are some suggestions for folks building new homes who are concerned about energy efficiency. What about if you're not building?
Well, the first thing I'd look at is insulation. Do you have any? If you do, what kind is it and how old is it? Might be time for an upgrade. If you have insulation in your attic, it might be as simple as blowing in some more. It can settle over time and may just need a booster. If you don't have any insulation in your walls, it might be easier than you think to add it. Think you have to open up the walls? Probably not. Small holes can be drilled in the walls, insulation can then be blown through these holes. The holes get filled with a plug and then a little patch job and voila! If your house is on a crawlspace and you don't have any insulation under your floors . . . yep, that can be insulated as well.
Filling any gaps is another important step. If you can feel air coming through any gap, then you're simply paying to heat or cool the outdoors because that's where your air is going! Windows, doors, trim, and basically any crack should be caulked. If you're building a new home or remodeling, caulk everywhere there is a seam. I'm not joking. EVERYWHERE. If you're not remodeling, can you see any open spaces or cracks around your windows either between the window and the casing or between the trim and the wall? Caulk those cracks. The best time to do so is when repainting. Caulk first, then paint over it. If there is air coming in between a door and the jam, and replacing the door isn't feasible, look at replacing the weatherstripping.
The photo below is one of many shots of my home under construction. I made sure to go through and take pictures of everything I could before it was all closed up. I wanted to have that photographic evidence of where framing, electrical, plumbing, and AV was. You think you'll know and it won't be a big deal, but if you are able to take pictures? Do it! I was told I wouldn't need that (and made to feel silly about it) and then not a week later (when insulation and sheetrock were in) a question arose. I said, oh I have a picture of that. I printed it out, we referenced it, question was answered. Then the same one who told me we wouldn't need those told me how glad he was I had taken them. Sometimes I do something smart. Hence having this photo to share. This should give you an idea of what your walls should look like . . .seal every crack you can find. Every last one.
Window coverings. This is sort of common sense depending on the issue at hand. In the summer, if you have west facing windows and sun just beats down on everything inside those windows in the afternoons, putting some thermal lined drapes or blinds there and closing them during those afternoon hours will help keep a lot of that heat out of the house. Then do the opposite in the winter. Open those window treatments during the day when you want that sun to come in and warm the house up, then close them up at night to keep the warmth in.
Supplemental Heat. I suppose this really depends on your specific situation. Space heaters CAN suck up a lot of energy, so I don't want to say "use them" and have everyone thinking they're going to lower electric bills. They probably won't. But in certain circumstances they can help. In my home office, where I spent the vast majority of every single day, sitting at my computer, working my magic, but not moving around much . . .well, I have a lot of windows in here. It's basically a small-ish bedroom with four good sized windows and an exterior door with a full windows. It's also on the opposite corner of my home from the geo unit heating it (which is at the other corner in the basement . . .I know, I should have known better and I didn't then, and I do now). It's the least energy efficient room in my house. It's also the hardest to keep warm or cool. Part of that reason is I often have my door closed (to the rest of the house) when my two indoor cats are being particular curious. One of them likes to attempt to play with every type of paper she can find . . .it's an office, there's a lot of paper. And the other one just likes to find whatever mischief she can. So it doesn't help with the heating and cooling as it reduces the air circulation on this floor. So what I'll often do in the winter is cheat the system a bit. I'll bring a space heater in here and set it about 3' away from me. I set it on whatever setting keeps ME comfortable, while allowing me to turn the heat for the entire floor turned down to an acceptable temp. No sense in paying to heat the entire floor when I'm in one spot for hours and hours on end. So think smart. Supplementing heat might not just mean heating with wood. If you only need to keep one location warm to save on heating the whole house, give it a try!
It takes some work, some money, and some smart thinking to create an energy efficient home. But there are really a lot of steps you can take, both big and small, that can make a noticeable impact on your electric bills. If you're building or remodeling, absolutely invest in the most energy efficient options available that you can afford. Do your homework. Seek out the advice of people who know more than you do. Or better yet, hire an energy efficiency expert to do an audit on your home. They'll be able to tell you exactly what you can do to improve!
Another thing worth mentioning is levelized billing. If you're not in a position to really do anything about your home, check this out. Maybe you rent and can't make changes, or maybe you simply can't afford to. Hey, we've all been there. At the very least, if a massive electric bill is going to derail your finances, see if you qualify for levelized billing. The electric company will average out your bills, charging you the same amount each month. I haven't personally done this, so others may have more feedback, but I would imagine it's reviewed and adjusted annually. My electric bills stay within an acceptable range all year long, even with extreme temperatures, so I prefer to just pay the billed amount. I also have some sick sort of fascination with attempting to get the bill as low as possible. Over the summer I had three bills in a row that were unacceptably high to me. I've spent about the past month refusing to turn the heat on (or the A/C as needed) in an attempt to lower that bill. I was successful! Lowest bill ever in this house! And now I have the heat on because it's ridiculous for me to sit here freezing! But if this sounds super amazing to you, contact your electric company. See if they offer this and if you qualify.
Sorry not sorry to have written a novel here. I daresay this probably could have been broken up into several different posts. However, the main point here was to skim over the likely reasons why people's energy bills spiked when we had severely low temperatures sustained an extended period of time in the South during January 2018. And to explain why the electric company most likely did not make a mistake reading your meter and what you can do to prevent a repeat. I suspect the nastiest of the low temps have passed for a few years, but who knows what future years may bring. We might not see 9 degrees this year, but 24 degrees can still leave it awfully cold in a home or cause some very nasty high bills. If you can learn a few things and empower yourself you can help prevent it from going out of control! This post sort of rambled here and there, but I hope even one of the above topics might help someone out!
If you have anything to add to this discussion, or if you have any questions, please comment below! As stated, I'm not an energy efficiency expert, but if I can answer or help out in any way I'll be glad to do so. Hopefully we'll have a milder winter overall this year than we did last and hopefully we can all make a few improvements to both stay warm AND save some money!
As always . . . devoted to design,