HRV / HVAC engineering help in Ontario
My building inspector came to do my HVAC rough-in inspection today. After he had ignored my e-mails and phone calls for 2 months, I gave up and just bought the Zehnder unit I wanted. The last thing he had said to me was he was “sure it would be fine”, and he’d call me back in half an hour (which he never did, called him again and got another promise of a return phone call that never happened). So now he claims he sent an e-mail telling me the Zehnder didn’t meet the Ontario building code, and needs a report from an engineer to allow it to pass. I thought I recalled reading someone on here saying they were part of a performance house HVAC design company, but I didn’t get the contact details at the time. Can that person, or anyone else for that matter help me out? I have a ground source geothermal loop that will be pre-conditioning the incoming air, so there definitely won’t be any issue with frosting the core. I need someone who can crunch some numbers, and has the right letters after their name to give me a report to satisfy this guy.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
Trevor,
Not sure what your inspector needs, but I think that your first phone call should be to Zehnder.
Every now and then, GBA has a Q&A thread about code officials rejecting Zehnder equipment. Here is a link to one of those threads: Zehnder ComfoTube code issue.
I misunderstood him in our prior discussion. He will not accept any unit other than those on the approved list. So there's no point going down that road. I'm sure the comfotube will also come up when he comes back. I am now convinced the Ontario Building code is a corrupt document that has only the surface appearance of being about building safety, efficiency and science. The more I learn about it and how stuff gets in it, the more disgusted I am.
Trevor,
A Zehnder rep might be able to tell you how many Zehnder units have been installed in Ontario, and the methods used to gain approval for these installations.
I work as an architectural & hvac designer with an engineering firm in Ontario. Trevor Day & Associates. You can contact me at e f o l e y @ n e x i c o m . n e t. However, I believe Zehnder has their own designers. I don't know if that's an additional cost to the equipment or if that design comes with your purchase. If they designed the system, they should be able to provide the required documentation. Which Zehnder unit did you install? A couple of them aren't HVI certified, which might be what he is looking for. 9.32.3.9.(1) requires fans to be rated according to CAN/CSA-C260-M, “Rating the Performance of Residential Mechanical Ventilating Equipment”, or (b) HVI 916, “Airflow Test Procedure”. Part 6 does not have these same requirements. You could have the system designed under part 6.
Zehnder is doing their best to resolve the situation. I will update when it's all over. HVI certification isn't the issue, indeed my inspector didn't even know what that was (seems to be a common theme that if it isn't explicitly mentioned in the OBC, he's never heard of it). The code req he's indirectly referencing is CAN/CSA C439, the proxy for which seems to be an Energy Star approval. The one I got is the CA350. Anyway, so it looks like I can't use your help for this issue, but maybe when he inevitably questions the heating system I'll heg in touch.
Wow Trevor, that's some scary stuff!!! I will be following this conversation for sure. In fact I'm going to "tag" my name here so I can find it with the search function: Lance Peters
If you don't mind me asking, which Zehnder model did you buy? Seems odd to me... they make some of the better regarded products on the market, you'd think you're safe ordering something like that!
I have the CA350. It doesn't matter a whole lot, this would apply to any of the European makes and models, as well as UltimateAir. None will pass the C439 test because they don't use re-circulation for frost protection. It's especially annoying, because re-circulation is just a cheat. It's like claiming your car is more fuel efficient because you left it in the parking lot. When an HRV goes into re-circ mode, it's no longer delivering the rated air flow, which is its only purpose. If it gets down to -40, it literally just stops. If you want to actually continue to ventilate at low ambient temperatures, you have to pre-heat the air, period. The C439 test will not allow it. If you use an electric heater, it will fail the for using too much energy. Even if you use a passive geothermal loop, apparently the test method actually adds the free energy you get from the ground into the equation so that it will still fail for efficiency. It's hard to imagine an explanation for that other than corruption.
It all comes down to how much of a stickler your inspector is. Some are very lax, some are reasonable and some are rigidly by the book. I would suggest if you are considering one, submit a ventilation system design and include the model of HRV/ERV. If they are going to take issue with it, you'll find out before purchasing it.
Thanks for the advice, Trevor. That definitely sounds like C439 is very poorly written. Hopefully eith Zehnder can help you out, or an approved HVAC design can be sourced without costing you too much. Let us know how this plays out!
Time to brush up on your paperwork-filling-out skills. Building officials love them some paperwork. You need to submit a Application for an Alternative Solution. Like this one: https://www.markham.ca/wps/wcm/connect/markhampublic/7a3a7be3-feff-4da4-8f6c-0520b1b39add/Alternative-Solutions-EDITABLE.pdf?MOD=AJPERES&CACHEID=7a3a7be3-feff-4da4-8f6c-0520b1b39add
No reason he shouldn't accept it if you can demonstrate that the efficiency of the unit will be equivalent to one tested according to CSA 439. You'll need some supporting documentation. Extra hoops to jump through...
At this point, I have more or less given up. I can already foresee a lot of problems with trying the alternative solutions route. In the best case scenario, it gets approved but it takes 6 months to complete the process. I don't have 6 months, I have negative 2 months. I already asked him about the Alternative Solutions route, and he insists that because it's a product approval issue it's not applicable. He may be wrong about that, but convincing this guy he's wrong about anything is nigh impossible. So that's several months just there. Then I have to find someone with a BCIN to be the "designer". Then I have to come up with the test data, which also means buying the CAN-439 code document and analyse it to ensure the testing is equivalent. From what Zehnder told me, there is actually wording in there specifically designed to prevent exactly what I'm trying to do; the only way to meet the efficiency requirement would be to use a ground source loop, but apparently that's addressed in the test and basically says you can't do it. It seems pretty bullet proof, this scam.
Trevor,
Yours is a cautionary tale for Ontario builders. Thanks for letting others know.
I hope you are able to either return the Zehnder unit or sell it on eBay.
That's ridiculous. This is exactly what the alternative solutions application is for. I'm sorry your building official is so un-pliable. The alternative solutions document get submitted to the chief building official though, so maybe he would be more sensible or have a better understanding of the code. Unless this building official is the CBO. The testing does not have to be equivalent, it just has to perform the same function at the same or higher performance level. A high quality Zehnder HRV will certainly achieve higher performance than a cheap builders grade HRV commonly installed. You just need to demonstrate this with some kind of proof. How much proof would vary with your building inspector but I would provide the Passive House test report and a bit of math showing how the efficiency of your HRV is better than a low grade HRV. Division C 2.1..1.2 which deals with tests in Alternative Solutions says you can use a test from different standards that provide comparable results.
You could also provide examples of this HRV being used in some of the highest performing homes around the world.
The applicable objective is OR2 which states "An objective of this Code is to limit the probability that, as a result of the design or construction of a building, the capacity of the infrastructure supporting the use, treatment or disposal of a resource will be exposed to an unacceptable risk of being exceeded."
The functional statement is F131 "To limit excessive energy consumption."
It should not be difficult to prove that it meets the function of that objective. The Alternative solution would be submitted with your building permit, which has a 10 day limit on when they have to issue the permit or refuse it and give the reasons why. No 6 month waiting period for you. Whoever your hvac designer is should be able to provide a BCIN'd (that's totally a verb) drawing for your ventilation. I know I do on every hvac design I send out.
Sometimes you just have to play their game...
Every time I lament living in a town with no building code or inspections, something like this happens and I'm glad.
"The Alternative solution would be submitted with your building permit..."
How does that get handled if the building permit was already issued? He said something on the phone to me (as part of his usual word salad in explaining why the Ontario Building Code is supreme and it's best not to question it), that was in effect "once your building permit is issued, no design changes are allowed".
The whole thing is made all the more frustrating by the fact that this guy generally takes 1-4 weeks just to reply to a question, always goes beyond the promised length of time to respond, and is unreachable by phone. So all I can do is e-mail, then wait for either a phone call or an e-mail. I'm currently waiting for approval for the use of Zhender's Comfoflex duct. He said he'd get right back to me as long as the approval is clear cut and he doesn't have to look up and cross reference the UL standards. He didn't get right back to me, and I've already gotten my phone call for this week so that means at least another week before he calls me back to tell me than UL 181 is not recognized by the Ontario Building Code.
"...this guy generally takes 1-4 weeks just to reply to a question, always goes beyond the promised length of time to respond, and is unreachable by phone."
Seriously?
Does this (so called) "public servant" have a supervisor to complain to?
Again, absurdity. You just submit a revision to your permit. The Building Code Act says "Notice of change: (12) No person shall make a material change or cause a material change to be made to a plan, specification, document or other information on the basis of which a permit was issued without notifying, filing details with and obtaining the authorization of the chief building official. 1992, c. 23, s. 8 (12).". The building department has to review the change and let you know if it will be accepted or not. If you submit revisions to your permit, I don't know if the same time frame applies. It doesn't seem to be spelled out in the code. You can contact the Building Code Commission regarding a building official who is not following the building code.
I would be asking the municipality to assign a different building official to your permit. This one is clearly not qualified to handle a permit that falls out of the ordinary construction practices.
Trevor,
That's an awful situation. My BI is in his office for an hour each morning and afternoon. I always leave with the answers I need. Right across the hall there is a planner available too. Both he and his predecessor also often stop by and eat their lunches with us on site if they are nearby. I don't know if I am lucky or you are unlucky, but either way that's frustrating.
Dana, the supervisor has been CC'd on a lot of the e-mails. She hasn't felt the need to say anything about the core issue, or the way in which it is being handled. There are no other inspectors for our municipality, and in fact this one is shared with another municipality so he only works two days a week for our area. That is a significant part of the response time problem.
Yupster, I've sent you an e-mail.
Thanks,
Trevor
Wow, just wow! I will be sure to be clearing every detail of my ventilation system ahead of time! Hopefully being within the Ottawa city limits will make things easier for me than what you're going through, Trevor. Good luck, and keep us posted.
UPDATE:
After a long, mostly pointless journey, a resolution is in place. Two key factors allowed us to use both the Zehnder HRV and the 3" HDPE ducting.
1)HVAC design specifying the HRV and 3" flexible duct (thanks to YUPSTER at Trevor Day & Associates for this; highly recommend for any potential design needs)
2)The discovery of a datasheet from Zehnder showing testing of their CA550 with a ComfoFond at -25C, and Zehnder's offer to upgrade our CA350 to a CA550.
You might be wondering why I didn't just get the design back in April, and be done with it. Well, I would have if not for a bunch of misinformation fed to me by the building inspector, and some miscommunication between several parties. I proposed many possible solutions to the inspector back in April; I asked about getting an HVAC design, the Alternative Solutions approach, and a proscriptive approach. I was told flat out that none of these had any chance of getting approved. This was the seed of all the time wasting, but many other factors helped it grow. The building inspector refused to communicate with Zehnder to determine exactly what was needed, so I was forced to be the go-between. This led to a lot of time pursuing things Zehnder guessed he took issue with; e.g. UL1812 for the HRV and UL181 for the ducting, neither of which he ended up caring about. Meanwhile I was not aware of the -25C data for the CA550 until quite recently, and I discovered it by accident on their website. In the end, I have to assume his supervisor must have said something to him, since the design and equipment he approved is exactly what he said he would never approve. Maybe he's just crazy. I don't know.
So, what is the take away from all of this? My exact scenario was the result of a huge number of converging storms (taking over the project in mid-stream from a scatterbrained builder, dealing with a difficult inspector, misinformation and miscommunication from all directions). It's hard to imagine something as convoluted as this ever happening to someone again. Have an HVAC design that calls out every detail very specifically. Everything else is detail dependent.
good advice Trevor, advice often repeated on this forum. Have a design done by someone qualified. When working with my HVAC contractor, having the full room by room heat loss calc on-hand meant ZERO chance of grossly oversizing/overselling. I also had the ERV design completed and was submitted with the building permit. We are going with the Venmar X24ERV which has all the creds. It's not quite as efficient as the zender, but it is getting close. Full install including duct work is 4K.
Ryan,
If the full cost of your Venmar ERV installation (including ducts) is $4,000, you are saving between $4,000 and $6,000 compared to the typical Zehnder installation.
You can buy a lot of electricity for the $4,000 to $6,000 you saved -- or you could use the money to buy a PV system rated at 1.1 to 1.7 kW.
Ryan,
The X24ERV is a nice looking unit; we looked hard at it (well, the vanEE version, the exact same except for the label - Venmar owns vanEE). Sounds like a very reasonable price, depending on exactly what your interior duct work is like. We were quoted about 2850, but that didn't include anything past the supply/return of the ERV. In the end, I think the Zehnder unit came in a little under 4k, but that's with me doing all the labour and not paying for the supply side duct materials. That probably would have added $1500 (less if we used generic duct, but that is more work). Also not included is the commissioning, another hit of about $750. I don't think it's fair to include that though, because it's comparing apples to oranges. The Zehnder commissioning is setting the supply and exhaust rates at each distribution point. The Venmar one is just sticking a differential manometer into two ports of the ERV and setting the fans so that total exhaust = total intake.
I think the efficiency of the X24ERV is actually slightly higher than the Zehnder equivalent, and the opposite is true if you're looking at the HRV versions. Ultimately, four things swayed us from the Venmar to the Zehnder.
1) Zehnder has swappable cores. We still haven't decided whether HRV or ERV is best for us. Now if we've made a mistake with the HRV, it's far less of a big deal to rectify. We could even swap seasonally.
2) Bypass mode.
3) Direct support from the manufacturer. The local HVAC contractors vary in their knowledge of dedicated ventilation systems, but the range of that variability is from very little knowledge all the way down to negative knowledge (e.g. one contractor insisted you could not install an HRV without a forced air furnace). So since I had to take responsibility for making sure our system was right, I felt it important to have a good resource. One call to vanEE tech support was all I needed in order to figure out it wasn't going to be them.
4) I really disliked their controller. This was actually the biggest issue, because it determines how the unit operates. You have almost no control over anything with Venmar's. Not only that, but the automatic settings don't even seem to satisfy the basic requirements of ventilation. You can run it full recirc, continuous on low speed, in 20min/hr mode or Smart mode. I can't even think of a purpose of full recirc mode. 20min/hr mode is almost as pointless, IMHO. If you look at the chart they have for Smart mode, there's pretty big chunks of temperature/humidity ranges where it is effectively not ventilating at all. (e.g. below 25%RH at -5C, it goes to standby for 50 minutes per hour - why? Same thing for 15C, >65%RH. Guess you don't need to breathe when that happens? And then it just shuts off completely >70%RH and >25C. Again, who needs to breathe, right?) This would all be fine if there was just a mode where you could set the fan speed manually (other than just low speed). Ultimately, I think the only satisfactory way to run this would be to run continuous at low speed, and program that low speed to meet the typical ventilation requirements. Notably, you cannot select a boost mode, so I don't know what you're expected to do if you have a party, or you want to increase the exhaust rate for showers or cooking.
Another nice feature that I discovered after the fact is that the Zehnder can be set to ramp up or down automatically based on carbon dioxide levels. Given the wide range of opinions on how much ventilation is enough or too much, I think this will come in really handy.
my zehnder quote, equipment only, including $700 commissioning was $10,191USD for the 550 unit, not including shipping taxes and duties. At that price point compared to the Venmar/Vanee, i honestly just couldn't swallow it. Even if for a few days of the year it gets stuffy, hopefully just general occupancy of opening and closing doors helps keep the air somewhat fresh.