After living in the house for 1½ years, I finally have enough distance to evaluate the many decisions that went into building it. I plan to write a long series of "Hindsight" posts, speaking frankly about what worked and what we'd do differently if we had to do it all over again.
For my first hindsight post, I'm going to keep it simple and talk about our kitchen appliances. Don't worry, I'll cover all the hairy Passivhaus details eventually, but it's been 9 months since my last blog post so I'll start at the shallow end.
When we built our house in Tucson, we found out the hard way that there are two categories of refrigerator: standard depth and counter depth. Counter-depth refrigerators look sleek amid the cabinets since they don't stick out past the counter, but they cost more, have lower capacity, and are generally less energy-efficient than their standard-depth brethren. Our kitchen in Tucson was designed for a counter-depth model, so we were stuck paying more for a smaller, less-efficient fridge. With this in mind, I designed our current kitchen to accommodate a standard-depth refrigerator.
My choice of brands was limited by my irrational grudge against the Whirlpool Corporation (I had a vexing over-the-range microwave experience with them back in '04), so I combed the list of CEE Tier 3 refrigerators and discovered that Frigidaire made a couple of likely 21-ft3 models.
We got the FGUI2149 (356 kWh/year) because our local vendor was able to locate one for us (it was a relatively obscure model), but the slightly-fancier FPUI2188 would have done equally well. Both models seems to have been discontinued, alas, but Whirlpool appears to still make a few with similar specs.
The shelves inside the refrigerator door are a good size and easy to rearrange, and I've never found myself cursing at the refrigerator, so it must be pretty good. My only gripe is that the cover of the ice cream compartment (which sees a lot of traffic in our house) has a cheap plastic catch and seems likely to break one of these days. There is also an occasional rattle when the condenser is on, but we've never bothered leveling the refrigerator according to the manual so I suspect that might fix it.
Long story short, if you have a time machine and can buy appliances that were discontinued two years ago, I can cheerfully recommend the Frigidaire FGUI2149. We haven't owned it long enough to know how reliable it is, but for now we have no real complaints.
No custom home is complete without a huge and powerful gas range. The ultimate expression of this would be a $50,000 La Cornue Grand Palais (which I invite you to purchase through my Amazon Associates link), but plenty of fine stoves are available for a mere $10,000 or less from Viking, Wolf, Dacor, and others. (I was also perfectly happy with my humble GE range back in Chicago, and probably would have done fine with something similar.) Ted makes a lot of stir-frys, so he longed for a lot of power, and a gas range seemed like the obvious choice.
But our blue-flamed ambitions came to an unexpected end when energy guru Marc persuaded us to skip the gas range and install an induction cooktop instead. In a super-tight house like ours, the combustion from a gas stove would require more makeup air than we would expect to get from random leaks in our envelope. Furthermore, gas cooking requires fossil fuels, and it would be nice to build a house that could operate exclusively from clean energy. Induction stoves, we learned, could give us a high-powered, responsive cooking experience without any carbon-spewing combustion.
Induction burners are electric, but unlike radiant electric burners they use magnets to induce a current in the metal cookware, essentially turning the pan itself into the heating element. They boil water extremely quickly, like a radiant electric burner, but they are every bit as responsive as a gas flame. And unlike a gas flame, the settings are electronic and therefore extremely consistent, which means I can set the burner to 7 and know it's exactly the same power as every other time I've set it to 7.
We bought the low-end Bosch induction cooktop (MSRP $1,699), and it has all the features we need. All it lacks compared with the higher-end models is precise heat controls, which allow you to press the "5" button rather than pushing the up-arrow until it reaches 5. But I don't mind using the arrow buttons (you can hold them down until they reach the desired setting), and the low-end model has the same cooking power as the others (the most powerful burner goes to 3,600W, which is roughly equivalent to a 26,000 BTU gas flame—insanely powerful).
It also has a separate timer for each burner, which is particularly handy when using the pressure cooker. For example if I'm cooking chickpeas, I bring the cooker to pressure, lower the heat, and then set the timer to 30 minutes. It stops on its own, and then the pressure releases naturally at its own pace—great for set-it-and-forget-it cooking.
Our cooktop gave us a bit of trouble initially, and we had to get the logic board replaced under warranty, but otherwise it's worked very well.
I don't have much to say about our oven, which is actually a fairly glowing recommendation. The controls are straightforward (I don't think I've ever had to consult the user's manual), and I can't recall ever being annoyed with it. The one weird behavior is that the fan blows for a while after you turn off the oven, but it's not obnoxiously loud, so I don't mind it.
I have mixed feelings about our dishwasher. It has some good features: it's very quiet, and it has a dedicated tray on top for silverware. But sadly it doesn't clean the dishes all that well. I checked the sprayers, I clean the filters regularly, and I've tried various types of detergent, but a few dishes per load tend to need soaking and rewashing. If anyone from Miele reads this, I invite you to contact me and troubleshoot this further, but for now I am not particularly impressed.
Externally-vented range hoods are not the best idea in a tightly-sealed passive house because they require a lot of makeup air, so we weren't going to install one at all. But Aubrey from Zehnder America, who sold us our heat recovery ventilator, recommended we get a recirculating range hood to suck grease and smoke from the air before the HRV exhaust vents suck it up.
Unfortunately, island range hoods are a lot more expensive than wall-mounted range hoods. XO Ventilation had the best prices (though Frigidaire seems to have introduced a few models as well), and the one we bought is fairly attractive. One of the lights didn't work, so we fixed that under warranty, but otherwise there's not much to report.
After writing this, I'm questioning the value of reviewing products that have been discontinued. But three out of the five appliances are still available, plus I might land a fat commission from that La Cornue Amazon affiliate link, so hopefully this wasn't a waste of time.
I've been sick with a bad cold all week, but I pried myself off the sofa this afternoon and took a walk down our wee woodland path. Our house is on a 2-acre lot, and most of our trees are north of the house, but there's a quarter-acre patch to the south that I plan to turn into a tiny woodsy circuit. It's all visible from our big south windows, so it will be enjoyable from both outdoors and in.
The entry point from our front yard:
That post is our personal weather station, provided by Efficiency Vermont to collect data for their study of our house's performance. The white bags to the left contain topsoil that was cleared from our site for construction and will soon be turned into raised garden beds (more on that below).
Heading deeper into the woods:
Our whole neighborhood is overrun with wild raspberries (red and black), but it's hard to pick most of them because of the prickly brambles. I've cleared this pathway hoping to access them better, and I'll also plant more spring bulbs to enjoy before the brambles start to grow. So far I've planted a smattering of daffodils, hyacinth, and squill, but I hope to load the woods with all sorts of shade-friendly bulbs.
Turn to the left and you can see the road:
Walk down the slope and turn left again to face the house:
I still haven't decided where to carve out the rest of the path, so the only way out is back the way I came:
The lot next door is not likely to be developed—our uphill neighbor bought it for extra privacy—so we don't foresee any invasive construction in that direction:
And now the front yard. The dirt is rock-hard after two years of being driven on by construction vehicles. But later this month our excavation contractor will come and terrace it into a large fenced garden. He'll build three retaining walls made from boulders, put down a layer of sand for drainage, and then cover it all with topsoil.
This year I'll concentrate on growing vegetables, but I'm sure I'll sneak some ornamentals onto the property as well. There's a spot near our driveway, north of the garage, that would look delightful with some flowering trees if I can find any that don't require full sun:
You can see the edge of the deck outside the front door—it's a lovely spot in the afternoon once the sun goes past the top of the house.
So that's the "Before" series, which I hope will be replaced over the years with heaps of charming "After" pictures. It's probably a good thing I don't realize how much work all of this will be!
One of the few things I miss about living in Arizona is my wee postage stamp of a garden. I had two raised beds, several fruit trees, and some lovely rose bushes. Like most Tucsonans we didn't try to maintain a lawn, instead covering most of the ground with gravel, and we watered the plants as little as possible using a drip irrigation system.
I miss my roses most of all. I was initially surprised to learn you could grow roses in the desert since I always associated them with northern climes, but then I recalled that roses have thorns, and any plant that can hurt you will probably grow brilliantly in the desert. And they did, year-round! In fact, I'm not sure I'll ever grow roses again, since I'll never grow anything nicer than this fragrant beauty from 2009 (note scale):
My tomatoes were not as uniformly successful as my roses. Arizona's growing season is enviably long (the last frost is mid-March), but tomatoes won't set fruit once the temperatures get too high, starting in June. They'll start fruiting again in September or so, assuming they didn't die from some other cause over the brutal summer. My best crop came from growing very small native tomatoes, but they grew so relentlessly that I was praying for frost by Christmastime, since my plants had sprung their banks and overtaken the entire back yard.
May 2008 (note the blooming ocotillo trellis):
December 2008 (yikes!):
(Frost came a few weeks later, and overnight the entire jungle withered and my garden's balance was restored.)
You can probably understand why gardening for only six months a year in Vermont seemed a little weak after my year-round Tucson shenanigans. My initial plan was to build a greenhouse, but I quickly realized I didn't want to heat a greenhouse. So we created a nice little garden space right inside the house, with huge south- and east-facing windows.
Speaking of Googling, I suspect I'm now on a DEA watchlist, because nearly all the online information about hydroponic gardening is about growing your own pot. My browser history is riddled with sites like rollitup.org, 420magazine.com, and growherbsindoor.info, which really have a lot of helpful information (even for chard-growing squares like me). There's a lot of winking in the hydro world ("Here's what you'll need for your... tomatoes"), and mail-order sites cater to their customers' need for discretion:
Here's what I bought, mostly from our local hydro dealer (cash only) and pet store. I divided the list into one-time setup items and repeat-purchase maintenance items:
Setup items (one-time purchase)
2 x 10-gallon plastic totes (opaque, roughly 7.5" high)
When you set up your system, you'll need a power drill with a hole saw the same size as your net pots (3" in our case) to drill the circles through the tote lid. Don't try to cut the circles with a utility knife; many have tried and lived to regret it, or so I hear.
Our system has a total of 22 plant bays, and underestimating the efficacy of store-bought seeds I started 50 seeds in the rapid-rooter plugs. This was unnecessary, since all of the seeds sprouted and I ended up discarding half of them.
The seedlings in their hydroponic bays:
I hadn't added the hydroton pebbles yet—our neighborhood hydro vendor said we could omit them, but our plants were rather wobbly inside the too-large 3" net pots, and I was concerned about sunlight streaming into the tub and causing algae to grow. This is why it's important to get opaque tubs rather than clear.
The arugula and Rouge d'Hiver lettuce turned out to be a poor choice, since you need a lot of plants to get a salad's worth of lettuce. The head lettuce varieties were better suited to our system, and after harvest I planted some more, along with some oak leaf lettuce.
We've now eaten everything from the first round except for the chard, which I am slowly harvesting for banana-chard smoothies, which taste a lot better than they sound:
As a passivhaus dweller who has not given up on achieving net-zero energy use, I was concerned about how much electricity my indoor garden would require. The answer: very little. The two aquarium pumps draw a combined 5 watts, and my abundance of natural light means I don't need supplemental lighting at all. If I were trying to grow fruiting plants like tomatoes, I'd need a 96-watt T5 fluorescent fixture as a bare minumum, and possibly quite a bit more, even with my huge south-facing window.
I may try growing tomatoes indoors this fall, but I'll likely abandon the effort if it needs more than 100W several hours a day. I tried starting tomato seeds in dirt but managed to kill them by overwatering. Next time I'll stick to hydro!
Unlike tomatoes (and "tomatoes"), hydroponic greens require very little work and maintenance. Every few days I check and adjust the pH levels (a slightly acidic reservoir of pH 5.5-6.5 is ideal for nutrient uptake). I might add some water as well, but we haven't had a major problem with evaporation, and my hydroponic system hasn't affected the indoor humidity level. The biggest chore is to change the water every couple of weeks. I opted not to plumb the garden area for water, since it's not near the bathrooms or kitchen and I didn't want to introduce a risk of leakage anywhere else in the house. So I made a little cart out of a furniture dolly and an extra shelf and push the tubs to the hall bathroom:
Then I remove the lid and rest it on some 2x4 scraps:
This is a good opportunity to check out the size and density of your roots (such photos are known in the hydro world as "root porn"):
(BTW, this is pretty tame as root porn goes, because most of those plants are new—only the two chard plants are mature.)
First I remove the airstones and dump the water out of the reservoir, and then I give it a hearty rinse with the shower sprayer to clear away any algae or slime. I haven't had any reservoir issues yet, so I haven't bothered with soap or hydrogen peroxide. Then I rinse off the roots as well.
Here's a look at the airstones. The idea is to introduce lots of oxygen bubbles into the reservoir, which the roots need. One of the best things for me about hydroponics (versus soil container gardening) is that you can't overwater the plants, and you can leave town for a few days or even a week without having to maintain the system. A long absence isn't ideal for pH management, but it probably wouldn't kill the plants in a system like mine.
I could probably get away with a single airstone for each tub, but the gang at rollitup.org and every other hydro site says the more bubbles the better. Speaking of bubbles, the pumps are audible but not annoying. We started with a really cheap pump, but it was decidedly louder than the Fusion Quiet Power and maybe only $10 cheaper. I meditate in the next room, and the pump noise is not an issue.
Sadly I will have to suspend my hydroponic adventures in the next month or so—the solar angle will be too high and I probably won't get enough sunlight. I'll have to content myself with outdoor gardening, which frankly scares me. Growing 22 little plants in a weed-free environment (in more ways than one!) is so much simpler than going outside and turning our ~1,800 square feet of tire-compacted front yard into the garden of my dreams, which you can count on me to post about in, say, 20 years.
We've been living in the house for a little more than four months now, but it seems like much longer than that (in a good way). The long ordeal of planning and construction has faded from our memories, and we're simply enjoying living here.
In most respects the house is performing extremely well. The 12,000 BTU heat pump is having no trouble keeping the entire house comfortable. Outdoor temperatures haven't fallen much below 20°F yet (-7°C), so it hasn't really been challenged, but we're not too worried. We left town for a few days last week and turned the heat pump down to 60° (it's normally set to 68), and it never even ran while we were away. The indoor temps ranged from 62-66°, even though outdoor temps stayed below freezing.
Our one complaint this winter is that the house has been extremely dry (relative humidity ranging between 20-25%), with our heat recovery ventilator running on low, at 62 CFM. This isn't too surprising, since Ted and I are only two people living in a fairly voluminous house without pets. We don't have any houseplants yet either, but I plan to remedy this soon by setting up our indoor vegetable garden upstairs (that will be a whole other post, hopefully in the near future).
For now our solution is to run a humidifier. (I know, so pedestrian!) The main problem is that the humidifier is quite loud, drowning out our whisper-quiet heat pump and HRV. Our long-term fix will be to add plants and see how that affects things, and then maybe get an ERV core for the ventilation system. It's pretty easy to swap cores, apparently, and the ERV will transfer moisture from the outgoing stale air to the incoming fresh air. Naturally, our many geeky onlookers (including Peter Schneider of Efficiency Vermont, who installed all the monitoring equipment) will be curious to see what difference the ERV makes for comfort and energy use.
You may have noticed that this post is called "Winter in a Passive House," and not "Winter in an Almost Passive House." This is because we built a full-fledged, certifiable passive house (pending the actual certification, which we haven't gotten around to yet). We made the decision ages ago, but I never changed the name of the site because I didn't want to jinx things. I'm not so worried now, since we did insanely well on our blower door test (91CFM, which translates to 0.29ACH50). I therefore feel pretty confident about our final PHPP numbers, even if we messed up a thermal bridge calculation or two.
I haven't decided what we should rename the site, so for now I'll just strike out the "Almost" and see where the spirit moves me.
Speaking of winter, here are some lovely new snowy pix!
Occupant behavior can make the difference between an efficient house and a wasteful one. Notorious energy hogs include plasma TVs, old refrigerators or freezers, ice-makers, and dehumidifiers. And don't overlook sneaky items like DVRs, always-on computer and entertainment equipment, etc.