I haven't been back to these forums in a while since we've been busy settling into our new house. I wanted to say thanks to everyone who answered my questions over the past couple of years. If I hadn't found these forums back when we were designing our house, I never would have included a good SIPs envelope along with geo-exchange, radiant heating, solar thermal panels, and drain-water heat recovery. Also, I would probably have a smaller mortgage. 

For those interested, here are more details on our new house.  While I'm nowhere near an expert like many here, I'd be happy to answer any questions you may have.  Thanks again!

Looks great! Congratulations on the house performance and rating.

Is it my imagination or does energy efficiency seem to lead to arts and crafts styling. Maybe something about the grouped windows for solar gain and the arts and crafts ethic for simple high quality design.

-Rosalinda

Dude. Nice work on the home and nice layout on your site.

Questions:

1) What do you feed from the Drain Water Heat Recovery Pipe? All the other cold faucets in the home except the kitchen? Toilets? Do you notice the effect when you take a shower? What size did you put in?
2)Is the mixing valve's sole function to keep feed to the tankless water heater from the buffer tank below 40C? How has that hot water system been functioning for you from a user point of view?
3) The WEL system - do you still like it? Do you think it can go the distance for even more complex systems?

1) What do you feed from the Drain Water Heat Recovery Pipe? All the other cold faucets in the home except the kitchen? Toilets? Do you notice the effect when you take a shower? What size did you put in?

We went with a Power-Pipe (R4-54), which extracts heat from the two showers upstairs. Our energy modeller indicated that the savings from a DWHR unit was basically nil which I found odd. I was convinced by the posts here and the Enercan study that DWHR was a good idea. Tough call though because the $1400 installed cost of the unit was getting close to the cost of another set of solar thermal panels ($2000). I'm trying to track effectiveness by measuring temperature differential between entering and exiting water when a shower is running. So far, it looks like we're getting about a 5 deg C boost when showering. In hindsight the extra solar panel might have been better bang for the buck.

2) Is the mixing valve's sole function to keep feed to the tankless water heater from the buffer tank below 40C? How has that hot water system been functioning for you from a user point of view?

Yes, the solar tank has gotten as warm as 65C on cold sunny days when the solar panels and the geo-exchange desuperheater are really boosting the water temp. So the main purpose of the valve is to knock the temp down to a safe faucet temp to avoid scalding. However, my plumber and builder convinced me that going with a NG tankless heater as finishing heating was a good idea. The unit apparently has to do some heating and can't operate in pure pass-through mode so the mixing valve knocks the water temp down to 40 C to ensure the tankless unit has to heat at least 9 C to final temp. The DHW system has performed really well. I'm especially pleased with the output of the solar panels since we live in a sunny, but cold area.

3) The WEL system - do you still like it? Do you think it can go the distance for even more complex systems?

The WEL is pretty good, but definitely a bit of work to get all setup. Took me probably 10 hours spread over the xmas holidays. I found two problems with plumbing connections while I was working in the mechanical room that I had the builder fix so the setup time was well worth it. I think it will scale well as I hope to add electrical usage monitoring soon. The vendor/manufacturer (Phil) is very helpful which make the DIY aspect easier. Here's my more detailed review of my WEL.

To answer some questions from another thread:

Great blog/website! Really like the logging data. I'm not sure what type of meter Enmax gave you but Is there any way to tie it in?

Thanks. The WEL logging system is pretty cool. I just have a standard meter from Enmax, I don't think it will do net-metering yet. Enmax has really dragged their heels on offering solar PV around here.

Would love to know how often backup heat comes on in the heat pump. Also how much power it is using itself.

The installer left the backup electric heat on the Nordic GSHP off. Even during the coldest nights (-35 deg C) this winter, the GSHP was able to keep up. It's a two-stage unit that would just run during cold snaps. House stayed nice and toasty though. Once I get some electrical usage monitoring sensors for the WEL, I'll be able to tell how much power the GSHP is using and can calculate COP.

On the waste water recovery unit data, I'm curious as to why there is small temperature spikes ( at night) when there is no water flow. I understand the drops, they would be heat loss due to venting in the stack but why heat gain? Is there times when Calgary's sewers have warmer air in them?

Yeah, the nature of the WEL temperature sensors is to drift back to room temperature when water isn't flowing (as shown by the flow meter reading 0 L/min). Once someone takes a shower, the pipes quickly starting showing the real temperature of the water flowing. Looking at last nights graph, our basement tenant took a shower/bath in the evening, then the system coasted until this morning when we got up and started using the hot water.

p.s. do you post from a Mac?

Yes, at home I use Google Chrome on a Mac. Too bad as this forum software only has decent editing of posts for Windows IE users. :(

Guy - great to hear you are not needing the backup. I trust you can save all your data to compare year to year for the next five? Many people feel that geo does not work well in a heat dominated climate so it will be interesting to compare annual data in four or five years.
Is there any way to track your actual cost of heating dhw? It seems to me that in some ways you are your own worse enemy when it come to the roi on the Power pipe. Between solar and dsh your hot water cost can't be very much even if you were finishing with a standard electric heater. Now if you'd put that extra bank of tubes in ••••. 'course you might need more water storage.
Bob

Guy - great to hear you are not needing the backup. I trust you can save all your data to compare year to year for the next five? Many people feel that geo does not work well in a heat dominated climate so it will be interesting to compare annual data in four or five years.

I think the heat-dominated climate concern is for places where most of the load is heating and only a little is cooling, thus the GSHP is sized to handle the heating and then way too powerful to work efficiently for air-conditioning. Luckily (or unluckily as it's currently snowing hard here right now), Calgary is 100% heating only with no need for air-conditioning. So the GSHP I purchased solely heats water for the radiant floor system.

Is there any way to track your actual cost of heating dhw? It seems to me that in some ways you are your own worse enemy when it come to the roi on the Power pipe. Between solar and dsh your hot water cost can't be very much even if you were finishing with a standard electric heater. Now if you'd put that extra bank of tubes in ••••. 'course you might need more water storage.

Yeah that's the stinker with building an energy efficient house. Every improvement you make in efficiency lengthens the ROI on other components by many years. We didn't build this house purely on a ROI basis. We wanted a house that could be net-zero (once we add solar PV in 5 years or so) with a low carbon footprint. These days you still pay a premium for that. Hopefully in 5-10 years, net-zero or near net-zero houses will be much more price competitive with standard homes.

Unfortunately the link for your house details is not working