Image Credit: David Goodyear
Image Credit: David Goodyear The fixed location of the through-the-wall thimble dictated placement of the boiler. The variety of stove pipe lengths available from ICC simplified installation. Connections at the boiler are hidden by a removable side panel. Once the system was plumbed, and could hold air pressure over a weekend, it was filled with water — 243 gallons, not including the water to fill the distribution lines to each radiator. Softline radiators by Stelrad require a low volume of water, resulting in less energy loss in distribution lines. The TRV valve that controls heat is on the lower right. The manifold for the heating system. A single Taco constant pressure pump provides all the power needed to distribute hot water to 12 separate zones. Below the pump, the Taco iSeries three-way valve mixes return water with supply water from the tank to modulate target temperatures based on an outdoor reset. Boiler controls include a thermostat (orange, at center) and a pressure relief valve on the left.
More Guest Blogs
Editor’s Note: This is one of a series of blogs by David Goodyear describing the construction of his new home in Flatrock, Newfoundland, the first in the province built to the Passive House standard. The first installment of the GBA blog series was titled An Introduction to the Flatrock Passive House. For a list of Goodyear’s earlier blogs on this site, see the “Related Articles” sidebar below; you’ll find his complete blog here.
The Walltherm is the showcase of the Flatrock Passive House heating system. As mentioned in previous posts, it is a wood-fired gasification boiler. With a efficiency of 93%, it dumps about 12.5 kilowatts into hot water while only 2.5 kW is emitted to the room.
It took four of us to move it with a hand truck into the living room. With the wall thimble already in place (see Image #2 below), there was only one place for the boiler to go. However, limitations in the lengths of double-wall stove pipe made the placement a little challenging. This being said, Excel ULTRABlack manufactured by ICC comes in a variety of different lengths, and they also have slip lengths to accommodate many set ups. So we placed the stove so the back was 10 inches away from the wall (minimum offset to combustibles, according to the manufacturer).
With the stove in place it was time to plumb in the various connections (see Images #3 and #4 below). Adam Rickert was on site to do the work. Connections include a supply and return from the tank, a thermostat that turns the pump on and off, a temperature gauge, and a manometer.
One issue we ran into with the stove is that the threads are made for European fittings. Although NPT threads fit fine, they bottom out completely once tightened since they are mating with a non-tapered fitting. The fittings required large amounts of teflon and leak lock to seal adequately and the results weren’t foolproof.
Multiple attempts to pressurize the system with air presented leaks between mated fittings. A local company, Island Hose and Fittings, carries Dowty Bonded Seal meant for this application. A bonded seal is really just a washer with a rubber seal bonded to the center hole of the washer. We switched directions and used Dowty seals instead since they provide a more robust seal.
The system was pressurized and remained pressurized over a weekend, so we felt that it was good to go for filling. The system was filled with water from the well using the automatic refill connected to the tank. It took almost 1.5 hours to fill the tank! At 243 gallons, plus the water needed to fill the distribution lines to each radiator, there is a lot of water! The well didn’t run dry so it’s a good sign that the well recovery flow rate recorded by the driller was probably pretty accurate.
With the installation complete, it was time to test the system.
Choosing radiators
Before getting into most of the particulars about the hydronic system and the Walltherm commissioning, I should discuss my choices of radiators. Nothing was available locally. Hydronic radiators are a specialty item so they had to be ordered regardless of brand name.
Jaga makes low-temperature radiators. They have a large surface area and provide high BTU output at low temperatures. Some of them have ECM fans to boost output. The price was beyond the scope of my build, so I abandoned that idea fairly early after I decided that I wanted to use hydronic heating. My HVAC contractor (Adam Rickert of Hot Water Systems) recommended Softline radiators by Stelrad, a low-volume radiator (see Image #5 below). The BTU output from the radiators was determined from load calculations provided by Passive Design Solutions. Moving water around at lower temperatures leads to less energy loss in the distribution lines even when they are insulated so I sized the radiators based on 120°F water temperature.
Controlling the temperature was the next question, and I had several options. Thermostats in each room with zone valves on a manifold would take up a lot of space in the mechanical room and required more controls and electronics than a simple TRV (Thermostatic Radiator Valves) controlled system. I decided that TRVs were a great option for a low-energy house and really simplified the distribution at the manifolds (see Image #6 below). They require no electricity and open and close based on temperature response. Coupled with a constant pressure pump (see Image #7 below), they provide all the same benefits as using variable-speed pumps and zone valves without all the electronics.
Commissioning the system
Commissioning the system was a lengthy process. First, it had to be filled with water. Once the tank was filled, ball valves to the radiator distribution manifolds were opened and lines were filled with water. Because the radiators are controlled by TRVs, they had to be fully opened to allow water to enter the radiators. Once the radiators were filled, they had to be purged of air. Each radiator has a air bleeding valve installed for this purpose. With the TRVs opened, the pump was set to provide 14 feet of head. Each supply valve was adjusted at the manifold to give 1 gallon/minute since the calculated load in BTU/hour was based on that flow rate.
When the wood stove is burning, the Logix24 tank could easily hit 80°C (176°F). Distributing high-temperature water is wasteful from an energy perspective and would lead to large temperature swings in each zone due to cycling of the radiators. The Taco iSeries outdoor reset mixing valve does two things to help solve this problem.
First, since the hot water in the return manifold still contains useful energy, it can be reused. The valve mixes some of that water back into the supply manifold as hot water is drawn from the Logix 24 tank. Second, the valve also uses an outdoor reset sensor to determine how much water from the hydronic return manifold it needs to mix with hot water from the Logix24 tank to modulate distribution temperatures as outdoor temperature changes.
As the temperature outside rises, the water temperature to the supply manifold decreases. As it gets colder, the water temperature rises. The system dynamically changes the radiator temperature in response to the energy loss in the building. This setup should be more efficient than a non-mixed system and temperature response should be more even.
Setting up the electrics
In addition to the Walltherm connection to the tank, we installed several 4500-watt electric elements to provide a grid-connected heating source. This provides much more flexibility than using wood alone. Electric elements can be used during the heating season when wood is not being burned and to keep the domestic hot water coil inside the tank ready for hot water use. We’ll use electricity when going on vacation and during the shoulder seasons when heating with wood will lead to overheating in the living space.
The water inside the tank is highly stratified. Water at the top of the tank may be at 60°C (140°F) while the bottom may be at 25°C (77°F). This provides a way to heat (“charge”) the tank partially with hot water and leave “storage” room at the bottom for wood heat.
I pre-designed the control system and my electricians (Trevor Leonard and Mike Molloy of 709 Electrical) made some modifications so it would conform to the electrical code. The control circuit is a little beyond the scope of the blog, so details are omitted for now.
The manufacturer of the stove provides all the safety equipment needed for safe operation, including a 30 PSI pressure relief valve (see Image #8 below). This valve is plumbed from the stove to the outside. Should the water pressure ever increase beyond 30 PSI, the valve will evacuate the hot water to the exterior of the house.
Likewise, if water hits 95°C (203°F) in the water jacket, a capillary temperature sensor opens a valve attached to a copper lance that is plumbed directly to 7°C (44.6°F) well water. The damper in the stove is controlled by a thermostatic control. As temperature rises, the stove damper (attached by a chain to the control arm of the thermostat) starts to close and air supply to the stove decreases.
To extract heat from the stove, the boiler charging set (PAW, Grundfos Alpha 1 pump) is thermostatically controlled and starts around 68°C (154°F). The pump was tested before the initial burn by turning the thermostat dial down until the pump turned on. Initially, the pump was noisy ( a good sign there was still air in the lines.) We had to use higher pressure water to force air through the supply/return and into the Logix tank where it could escape through an automatic air vent.
With all the testing and verification out of the way, it was time to light the stove.
Time for a fire
Building a fire is tricky at first but once you get the hang of it, it’s not that hard. Everything depends on the bed of hot embers filling the area around the injector plate at the base of the firebox. The trick is to start with kindling and then add larger pieces of wood. After 20 to 25 minutes, the water in the boiler is about 50°C (122°F) and the flue temperature is over 400°C (752°F). Actuating the gasification process is just a matter of pulling a lever on the side of the stove and, Voila!
The temperature in the water jacket starts to rise significantly and the pump comes on. The flue temperature drops to around 150°C (302°F) as heat from the flue gas is absorbed by the stove heat exchanger. Kindling and six pieces of wood burn about 2.5 hours. I estimated there was a temperature rise of 72°F based on the temperature gauges on the tank. This is equivalent of about 23 kWh of heated water.
After this time, the whole tank has a temperature of about 149°F. Since the mixing valve tempers this water to around 95°F (at least during the spring) that is more than enough for heat and hot water for the next day. During a 2.5-hour burn, the house received about 5.6 kWh worth of space heat, so radiators on the main level won’t come on at all while the stove is burning. They typically come on the next day if it’s not sunny.
Overall I am pleased with the system. The house is amazingly comfortable with the low-temperature radiators. The only thing I am sorry about is that it is almost the end of heating season for our house according to the WUFI model …. so it may be next year before I really get to use it extensively.
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39 Comments
Wood-fired boilers
David,
I've had an almost 40-year fascination with the idea of a wood-fired boiler, ever since I saw an HS Tarm boiler at Louis Mackall's house back in about 1980. There is something elegant about a hydronic system that burns a fuel that is easy to gather.
Your system is a nerd's dream. I can imagine that it will be satisfying to operate.
All of that said, my fascination with wood-fired hydronic systems has faded over the decades, for a variety of reasons: the design heating load of a well-insulated building is usually quite low, so it's a rare day when you need to keep a wood fire going for long; burning wood releases particulates, which are harmful to human health; a "front-loading" analysis of the carbon releases associated with wood burning reveals that these carbon releases aren't good for the planet; and hydronic systems are mechanically complicated (a fact that raises maintenance issues).
Good luck! It's fun to read about your system.
Wood-fired boilers
Martin, The designed heat load for the house in the middle of winter is somewhere around 4.5 kW. The stove outputs about 5 kW without the insulation kit. The insulation kit and IR glass, the output drops to about 2.5 kW. Luckily I researched most of this as we were designing the house so I could match the output to the design load. Luckily, for this low energy house, it looks like a 3 hour burn per day (5-6 chunks of wood 4" in diameter) will give enough space heat and enough thermal storage to heat the house and provide hot water for a day, or more depending on the outside temp. We have used the stove quite a bit now and the living room gets warm but not uncomfortably warm.
I don't dispute the front loading analysis. I based my choice on many variables. Particulate emissions was one of them. I dont claim to be an expert in the emissions standards so I don't know if the standards are a good metric to meet but the stove does meet meet the EPA phase 2 boiler emmissions and my understanding is that the stove typically produces about 0.3 g of particulate per kg burned. Assuming I burn about 1 cord per year, I will release about 0.5 kg of particulate (I may have this calculated wrong). Is this insignificant? Probably depends on what you want to compare it to. Also, burning 1 cord of wood a year is a much more sustainable practice than burning 6-7 cords as is typical in most wood burning homes in Newfoundland.
I agree, they can be complicated. I have tried to make mine as simple as possible. For example, a single constant pressure pump feeding a manifold without zone valves. Choosing TRVs for my thermostats. There are ways to make it simpler but hydronic systems are typically more complated than most heating systems. My HVAC installer said most of his clients are doctors and engineers! Im a physicist. The demographic drawn to these systems is interesting to say the least. Luckily for me, I can do my own maintenance....hopefully!
Thanks for the commentary and I am glad that you enjoyed reading about the system. We enjoyed designing it!
great article
Hi david, thank you for the detailed article!
Could you elaborate on the cost of the entire heating system? Do you have plans for AC, or is it not needed in your climate?
Cost
Hi Mike,
The stove is about $7000 CAD the tank $4300, and I lost track on the hydronics but it wasn't cheap. This being said, my reasons for wood with the hydronic distribution is so wood could be used as a primary energy source for heating/DHW once electricity rates double. Maybe a solar panel system would have been possible but at the time we started building, net metering was illegal. Even with net metering, meeting net zero here would be fairly difficult under the current situation. The solar potential is almost the lowest in Canada at 970 kWh/kW so the payback is long ie 20-25 years. That will half once Muskrat falls comes on line and power rates double.
As for AC...we are now 2/3 of the way through the coldest june in history. With daily highs of 9 C and lows of 0 C, its still heating season and in two days it will be the first day of summer! We typically have about 5-10 weeks of hot weather depending on the year usually starting around July 1. After July 1, temperatures soar to 25 C! Stifling hot! This was all said "tongue in cheek"! So AC is not necessary but it does add to the comfort level. I am working on installing a Nyle geyser-r that should provide some hot water and all of the AC needs for the house as a byproduct of hot water production.
Thanks for the numbers David.
Thanks for the numbers David. I went with mini splits and solar here in Massachusetts, but we have very generous rebates/net metering (3 year payback on a 10.56kw system).
I was very interested in the Walltherm, as we have a heavily wooded farm that offers free fuel, but could not get the costs to compete, even before factoring in AC. I do feel that without solar, gasification is the way to go heating wise.
efficiency
> Distributing high-temperature water is wasteful from an energy perspective
I say that higher temperature water means less pumping costs for a given amount of heat moved.
> would lead to large temperature swings in each zone due to cycling of the radiators.
Why? You have a TRV to modulate the flow to match the room load.
I assume that active thermal mass (eg, a water tank) provides steadier air temperatures, less frequent burns and cleaner burns than a tankless, non-hydronic system.
Not to mention... @ Jon R
...that since (in this case) the boiler and plumbing are entirely within conditioned space higher standby & distribution losses related to the higher temps aren't really lost.
That's not to say that the Taco iSeries isn't a good solution, but it could end up using marginally more pumping power to distribute the heat than some other solutions. (A very small fraction of an already small number, to be sure.)
efficiency
I think the pumping costs are small compared to the total heating costs. The losses can be high through the distribution lines since the R-values are typically only about R-3 or R-4 for pipe insulation. The losses would be proportional to the difference between the water and the ambient air temperature. The heat loss for lets say for 140 F water compared to 95 F moving through the same distribution pipe with the same R-value water would be (140-68)/(95-68)=2.66. Moving the 95F water is more efficient and allows you to get more heat where you need it ie at the radiators.
When the heat load requirement is small, I think that the higher thermal mass of the rad and tmperatures local to the TRV will be higher causing it to close leaving a mass of really hot water in the rad to cool down. if the rad hasnt delivered enough heat, the trv will open again and the system will cycle. I believe that this is one of the benefits of low temperature systems. Although the distribution is all within the thermal envelope, having the heat delivered to the rads where the heat is needed is more important than having it delivered by heat loss through the pipes and between the joist space for example.
The thermal storage really provides a way to burn quick and clean and store about 85% of the energy. Otherwise we would be opening windows and wasting all the wood heat.
Please by all means, correct me if I am wrong.
TRV
A better calculation would be if the greater heat (btu) misdirection (not losses) from higher temp insulated distribution pipes is enough to worry about.
A TRV modulates. Ie, it doesn't cycle between open and closed. But that doesn't guarantee that it's a stable control system that doesn't oscillate.
AFAIK, the primary benefit of outdoor reset in a systems with TRVs comes with boilers that have higher efficiency when producing lower water temperatures. That doesn't apply when OR is only used to control the distribution temperature (and it depends on the boiler).
Would be interesting to turn off OR and see how much difference it makes.
Jon R
my main reason for the reset is that the water in the tank can easily hit 80C, mixing it down using some return water made sense at the time for moving low temperature water. Its also much safer with kids around. This all being said, it is funny to feel a radiator with a temperature of 95F when the outside temperature is about 32 F...yet the house is still warm.
"...misdirection (not losses)..." is correct. @ David, Jon
If it's all inside of conditioned space the distribution losses are still heating the house, just not the particular radiator or zone that was actively using the hot water. They are NOT losses, since the distribution losses accrue to offset the heat load of the unintended zones they are heating.
A primary benefit of outdoor reset (ODR) is room temperature stability/comfort. In a high-R house it's debatable whether ODR really adds much to the comfort factor, since there isn't going to be a rapid or deep chill after the thermostat is satisfied under any circumstances.
In a Passivehouse it hardly matters whether ANY of the heat makes it to the radiators. The notion that "...having the heat delivered to the rads where the heat is needed is more important than having it delivered by heat loss through the pipes..." just isn't quite true. Bear with the napkin math on this:
At a temperature difference of 110F (180F water, 70F room) the heat loss through R3 insulation on half-inch PEX is 15-20 BTU/hr per running foot. A sitting human emits about 400 BTU/hr. That mean it takes about 20-30' of 180F/R3 pipe to add up the an occupancy difference of just one sitting person. It's hard to imagine how that would create a perceptible comfort (or even easily measurable) difference in any of the "illegitimate" zones that might be experiencing the parasitic heating from those losses, or that the right-sized radiator wouldn't get enough heat. If adding one more person to a room than expected is a temperature control or comfort problem perhaps we should be running around in personal thermal-control suits and just forget heating the house. :-)
While 180F water isn't necessary for delivering the heat (or comfort), neither is ODR in a PassiveHouse. The number of occupants of the room makes as much of a difference in the room temp & comfort as the water temperature delivered at the rads. You might as well just set it to 120F (since that's how you sized the rads) or even 140F. It would be difficult to tell the difference comfort-wise between that and a continuously variable water temp that might even drop below human body temp.
It's true that as a percentage of the total heating bill the pumping power is pretty small. Even at a 90%+ pumping duty cycle ECM drive pumps operated at constant pressure like that Viridian won't add up to a double-digit percentage of the entire heating bill. (It can be that high using old-school pumps in a low heating load/high duty cycle scenario.)
Dana
As usual, informative. Dana makes some good points.
So all in all it seems that my heating system has generated some discussion. I am happy about this because I get to hear about things that I haven't considered or can learn something from. My primary reasoning for the hydronic system was being able to burn at high efficiency and deliver that heat at a later time while decreasing my dependency on the grid. I think we can all agree that the system does achieve that goal.
Dana, I love the napkin math! I do napkin math all the time...usually on post it notes! I can barely see my desk when I get on a roll!
Yes, that's the way to run a wood-burner! @ David
Being able to fire the wood boiler at it's optimum combustion efficiency, storing the heat for later is the right way to do it, especially at your very low average loads.
A wood boiler can deliver the heat at miniscule rates out of the thermal mass storage between burns, and at a peak output of 2.5kw (8500 BTU/hr) into the boiler room and won't turn the place into a sauna during the burns, utilizing the thermal mass of the house to soak up the intermittent excess during burn periods. A burn cycle at 93% efficiency and storing the heat is quite a bit better than a throttled back firing rate at 65-70% efficiency, no storage.
By contrast a plain old wood stove has no thermal storage to speak of, and only about a 2:1 or 3:1 turn down ratio to at firing rates that deliver the best efficiency. (And the heat can't be easily redistributed to remote rooms, unlike hydronic systems.) While wood stoves can be throttled lower, at very low fire efficiency drops as emissions go up.
Response to Dana Dorsett
Dana,
Right.
Except my old-fashioned wood stove (which heats my whole house), cost me only $100 when I bought it. (Used, of course.) Just saying.
It sounds like David Goodyear's system (including radiators) cost something north of $15,000. I'm not sure whether that includes any labor cost, but it sounds like it didn't.
David's system burns more cleanly and efficiently than my old wood stove, of course.
I hear ya! @ Martin
The older wood stove will use nearly twice as much wood per BTU delivered and won't heat the house as evenly as the hydronic system, but USD$15,000 buys a lot of wood (and even more chainsaw maintenance + gas).
My contractor-installed ~80% efficiency soap-stone model ran a bit over $5K all-in (including stainless flue liner, and outdoor combustion air kit.) It can heat the whole house too, but some of the bedrooms run pretty cold at design temp when that's the only source of heat in the house.
If my house were anything like a PassiveHouse (rather than the tightened up 95 year old antique that it is) that wouldn't be an issue- it would all be "warm enough" even with point-source heating.
less grid dependence?
With your system the majority of your heat energy is non-grid while the majority of your heat distribution energy is very grid dependent.
During a power outage, is the heat energy that would normally be heating water lost up the chimney?
At first blush, this seems only slightly less "grid dependent" than burning fossil fuels with a typical forced air distribution system. The difference is that the remaining direct heat will likely suffice for a Passive House during a grid outage.
less grid dependence
Hi, the answers are discussed above.
Why not electric heat
Hard to understand that with the low cost of solar, why would any house, especially a passive house, need to create carbon in our atmosphere for heat. I am running both my Nisan LEAF and electric cove heaters at my house off my grid tie solar. Also heating my water with a small tankless electric water heater.
Electric heat
At the time we designed the house, grid tie was illegal. I won’t get into the politics of this. Also there are no solar incentives. At about 12000 kWh per year for total energy usage we would really need a 14kW system because the solar potential is pretty low ie 970kwh/kw and to account for future degradation of the system. The system would cost about 30000$+. Grid tie is now
Possible but there are no incentives to help offset cost. Most of my reasoning has already been explained above so Have a read through if you have a chance.
I looked this in the design
I looked this in the design stage as well. Like you, we have no grid tie option, so solar was off the table. In the end, I couldn't come anywhere close to justifying the cost premium of this over straight electric. Our peak heating demand is less than half of yours, which obviously makes a difference. The other two things it had against it was the rather large footprint of floor space it takes, and the aforementioned emissions.
David,I had been wondering
David,
I had been wondering why you would prefer a wood burning heating system, the lack of a grid tied option explains it completely.
I recently priced a 12kW system for my house in Halifax, $35000 CAD was the estimate. I'm hoping I can get our homes consumption down enough that with the delivered ~14000kWh would be enough to cover the house and two electric cars driving ~15000 km/year. Comparing the price of gas to the cost of solar, and offsetting our power bill, that works out to about a 7 year pay off, without factoring inflation. But if I compare the cost of the power used by the cars to solar the payout period stretches out to about 15 years. We do have a good net metering policy here, but wow these prices for solar aren't helping anyone.
Oh, and thanks for share your experience in building your house!
Wood heat, emissions, etc
I get the feeling that several people object to wood heat and my decisions and that's OK. I can't apologize but I can provide some more background. I tend to research my decisions to death. I typically don't do anything on a whim. In the past two years I have changed my lifestyle significantly. I am infinity more energy conscious than I ever was. I feel guilty when I drive my gasoline powered vehicle but I do so as efficiently as I can, ganging up chores with trips back and forth to work, not taking frivolous Sunday joyrides. I only travel for work when necessary. Does the cost of the fuel matter to me. No. I really don't care about the cost, but I do care about burning the fuel wisely regardless of the price. Would I like an electric vehicle? yes, unfortunately that option is not ready for Newfoundland but I wish it were.
My new home has provided me with other options to make a difference. I now have a grassy field growing that will only need cutting once per year. I used to mow 3 times a week because of protective covenance in my old community. I have turned the whole back yard of our new property into a potato field and root vegetable crops and plan on doing it as organically as possible. We have changed the way we eat. Purchasing local, growing our own, foraging for local food, all to minimize impact as much as I can while I am here. I am currently building a cellar for long term storage of food items. I could have purchased more refrigerators that use more energy but I decided to spend a little more to create underground storage instead. I stay away from non-renewable fuels like propane which are imported into the province. In NL we have become far too dependent on the mainland. We have a 3 day supply of many items and I have seen what happens when ferry service is unable to operate. When food and good supply chains are disrupted, people get nasty. I have seen it. Besides, why should I buy carrots imported from Israel? Yes Israel!!! when i can grow them in my back yard.
I guess I just want to point out that our low energy house is just part of a bigger picture to help minimize my impact in the short 80 years that I have on the planet, create a more sustainable future for my family, to show people that change is good, even if it is combining some old ways with the new. I am only sorry that I didn't start thinking about this sooner.
The World is A Better Place
I've followed the progress of your house with a great deal of interest. Lord knows I haven't agreed with all your decisions as to layout and functionality, but you've built a very pretty house. I noticed that in another blog posting you stated that "a house is more than blueprints and numbers". Actually in your case, your entire home is nothing but blueprints and numbers. Throughout the entire build you've been obsessed with Passive house standards, building envelope decisions, product specs and blower door tests, all in order to achieve some magic number of "sustainability". Now you write about your desire to make the world a better place through the construction of this house.
I'd like you to consider something. Let's say that you lived in the ONLY house in Flatrock Newfoundland and it took 50 barrels of oil to heat your home every year (and all that oil has to be trucked in from somewhere else). When oil is selling for $35 a barrel it's a hefty cost, but not unmanageable. However, when oil hits $150 a barrel that's outrageous. You can't continue paying that much, so you decide to build a Passive house that only needs 10 barrels of oil a year to heat.
Have you made the world a better place?
No. You know why? Because in order to pay for your new Passive home you sold your old drafty, leaky home to someone else. Now there are TWO houses in Flatrock, and the oil company has to deliver 60 barrels of oil, 10 barrels for you and 50 barrels for your neighbor.
You spent a lot of money and time in designing and building your new house but you didn't improve the world, you made it worse because of all the extra materials, labor and energy used to not only manufacture the building products, bring them to the site, assemble them and now heat and maintain it.
I recall you mentioning in a previous comment that this new house is basically an improved version of your previous house with the same basic layout and all. Why didn't you just fix the old house? If you had done that you may have reduced your energy needs by half (but not to Passive house standards) and really done something to make the world a better place. Or was this entire process really just a numbers game?
Holy Moly!
Ouch!
Thank goodness NL has oil.
Reply to Scott
You wrote:
"Because in order to pay for your new Passive home you sold your old drafty, leaky home to someone else. Now there are TWO houses in Flatrock"
This makes no sense. It's a complete straw-man argument. He isn't the only house in Flatrock, and someone wasn't lured out there to live because David's old house became available. Every new house does consume more materials and energy than staying put, but unless you live in an area with a declining population, where are people supposed to live if we don't maintain and expand our housing stock?
The other implied criticism is he lives in a remote area to which energy has to be transported. i'm no admirer of the suburbs, but unless we are all going to huddle together in dense urban areas and leave the whole rest of our country unpopulated, houses are going to have to be built in places like Flatrock, and David has done the community a service by building a really well performing one. I don't think he should face some moral approbation for having done so.
What Malcolm said.
Scott: do
What Malcolm said.
Scott: do you suggest no one ever build a new house? Eventually, nearly every existing house will be torn down, or fall down. Doesn't it make sense to gradually improve the average house by building energy efficient new ones?
In Response
No, I don't think people should stop building houses. I think David has built a fine house which I'm sure will live up to his Passive house standards. What annoys me is his statement that
"our low energy house is just part of a bigger picture to help minimize my impact in the short 80 years that I have on the planet, create a more sustainable future for my family".
Adding one new house to the world's inventory doesn't minimize your impact on the planet, it adds to it. All those building materials have to be produced, transported, assembled into a house, water and sewage lines have to be run, more electricity used, more trees cut down to heat it, more money spent to maintain it.
The thing not talked about is what happens with the old house, the one they sold to pay for this one. Yes, there will always be people looking for a home, but that house is still as leaky, drafty, and inefficient as it was before he sold it, and passing the problems off to someone else doesn't mean that you are now a champion of the earth.
If you really want to improve the world then improve the housing stock you are living in now. To use another example, if I'm driving around in an 15 mpg gas guzzler and I sell it to buy a Prius I haven't done a thing for the world if the gas guzzler is still on the road. All I've done is pass the problem on to someone else.
Throughout this entire blog series I've had the impression that the entire reason for building this house was not to create a safe, energy efficient home (he could have done that with his old home) but was instead a scientific study in how to assemble a bunch of technologies and products and end up with a Passive house he could boast about.
"I have a 0.1% air change per hour number, what's yours".
The fact that he didn't even really solve any of the layout, functionality or traffic pattern problems in the new houses design only compounds the problem. He just built the same house he had before, All in all, I think this entire building is simply a vanity project for David, something to boast about and get some praise from the building scientists. But he certainly hasn't done the community a service.
Vanity Project....Holy Moly!
Scott
I don't know why you have taken against David. I have noticed you do get quite annoyed when people don't follow your architectural suggestions, but leaving that aside, your larger argument still founders on the rocks.
At it's core it is a neo-Malthusian criticism: Each new use of resources damages the earth. And taken to its logical conclusion, if David really wanted to make a difference he should have committed suicide in an environmentally friendly way. You are still working on the basis that in any transaction there are only two parties. The one in the new house or car and someone who has the old one. How do we as a group get to live in energy efficient dwellings or vehicles? Surely it's by building or buying them. Over time the entire stock or fleet is replaced. How is that bad?
I'm not big on the "I'm going to change the world" arguments when someone builds a house, but that's not what David has said. He as an individual has made some choices he hopes will reduce his impact on his surroundings. That's a petty modest claim, but something a lot of us can't make.
I don't
I don't have anything against David. I don't even know him. All the information I have regarding him and his build has been provided through his own writings, his drawings, plans and pictures. I do however, have problems with his house.
As I have said before, it seems that throughout this entire build the main goal and purpose to build has been to achieve "Passive House Status", not to create a practical and functional home. Every blog he's written has focused entirely on some system, product, or design feature that will tighten up the building envelope and get that coveted "air changes per hour" number below whatever the Passive house people require in order to issue you their plaque.
What irks me is that basic, common sense design decisions got overlooked (or completely ignored) in the race to the Passive house finish line, an example being that you don't route a major circulation pathway through the kitchen work triangle. That's basic common sense. Any first year architectural student would have caught that. To make matters worse, the entire main floor of the house is poorly laid out. The sheer amount of space that's completely wasted on hallways is pointless, and the leftover spaces, such as the mechanical room and garage entry mudroom are far too small. Ninety five percent of the time they'll be entering the house through the garage/breezeway/mudroom. Who wants to have to cut through the livingroom or dining room to get to the kitchen? These aren't MY architectural suggestions, they're basic common sense organizational guidelines. Any designer should have caught these flaws and corrected them before a shovel went into the ground.
David can build any house he wants, in any size or style he wants, but in the race to the Passive house finish line all he did was create a very efficient, very expensive box with a lot of poorly functioning little boxes inside it. Just because he could afford to build this house doesn't mean he should have. I just wish he'd posted his first blog 6 months before he'd actually started building so these basic layout problems could have been corrected.
As to his previous house, I still stand by my opinion. It's still as inefficient, leaky and wasteful as it was when he owned it. The world didn't get any better by passing it off to someone else. You say that over time the entire stock or fleet is replaced. Not by using Passive house design standards. Their system is so involved and specific that retrofitting an old house to bring it up to their standards is practically impossible. And that is ultimately the reason why David decided to build new. He wanted a "Passive House Showplace", not an improved older home. He could have really helped the world by renovating that old house and decreasing the amount of fuel and energy needed but then he wouldn't have received his plaque.
Scott
Oh those new-fangled architects actually encouraging visitors to enter the kitchen and treat it as a public entertainment space. Fussing with air-sealing and disregarding their elders advice! Thank God you and I are old enough we won't have to endure it much longer!
false premise
Scott,
The fact that he sold his house to build a new one is not relevant to the argument you're trying to make, unless your argument includes the idea that all construction should stop. Whoever bought his old house needed a place to live. If David's house didn't go on the market, another house would have sold and it's likely another house would have been built. That's the comparison that should be made, between David's new house and what a typical new house would be like. The scenario you present wherein there is now an extra house, consuming extra energy on top of the original one is true only in the very short term. In the long term, that's not how it works.
You said,
"I don't have anything against David...I do however, have problems with his house."
I think this is a meaningless equivocation, given the content of your criticisms. I personally think you've gone over the line from criticism to hostility.
You also said,
"And that is ultimately the reason why David decided to build new. He wanted a "Passive House Showplace", not an improved older home."
I suggest you should be careful when you try to intuit someone's motives and thought processes, and you should be even more careful about proclaiming the conclusions you come to as facts. You're speaking to things you can't possibly know.
Scott, I assume this is your
Scott, I assume this is your website: http://scottwilsonarchitect.com/? If so, considering your continued hostility toward David's architectural decisions and motivation, it seems a bit disingenuous since you design second homes and estates for clients, which include a lot of extraneous details, convoluted rooflines, unnecessarily expensive materials, and other things that may seem attractive to you or your clients but that are strictly elements of architectural vanity.
I've appreciated David's willingness to share his process and decisions, and his layout seems to work for him.
In most cases I don't believe that single-family Passive Houses make financial sense, but it's people like David who are pushing the envelope forward, and help "Pretty Good House" ideas seem reasonable.
If you have a design philosophy or project that you think should be shared, I suggest submitting a proposal to Martin for publication.
Housing needs
To just keep up with the population growth in the rest of the country (1.2% in 2017) Flatrock needs to construct 7 houses a year.
Sometimes Scott's comments, attitudes, and opinions are a little overbearing. I do feel like this has become somewhat hostile and I wouldn't want to "irk" Scott further so I will keep my reply short. My feeling is that, regardless of whatever justification I provide, it will be returned by some contrarian attitude.
Adding to what Trevor pointed out, Scott appears to be mouthing off about things he possibly couldn't know like: "And that is ultimately the reason why David decided to build new. He wanted a "Passive House Showplace". This is simply not true. Other than saying that I will be using my knowledge to move forward I don't really feel a need to say anything more about Scott's comments or further justify what I have done to him.
I’ve been in the custom residential design/build industry for over 38 years, and if there is one thing I’ve learned is that the homeowner gets to choose how their house works and looks. The idea that everyone should build a house with “common sense design decisions" that "got overlooked (or completely ignored)”, not only is arrogant, conceited and elitist, but is also ignorant.
I’m sure every design professional can criticize anyone's project, as all of us do not have the same ideas, likes and styles. Respect for other’s designs is one of the first lessons I learned in Architectural school.
David,
Don't worry about it. It's all water under the bridge. The post are months old.
Impressive System David!
Is there a reason why your boiler system wouldn't work well with radiant heat in the floors instead of the radiators?
Is there a reason why you chose not to go that route?
This is what I'm leaning towards doing in my house I'm building now to live in for the majority of the reminder of my life.
thanks for all the info you have provided. It's been super helpful!
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