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Anybody familiar with British Columbia building codes?

Pascalli2 | Posted in Building Code Questions on

I am building a home in BC, and plan to use Lunos e2 for my HRV. There is a lot of stuff about ventilation and HRV in the latest code revision (Dec 2014, I believe). Is there, by any chance, anybody out there familiar with the BC codes that can tell me if I am going to experience issues trying to use the Lunos fans?

A couple things that I am concerned about (off the top of my head).

– The code seems to want a single switch that is to be left on ensuring the fans are always running to the minimum cfm – this requirement seems based on a centralized ventilation system and not necessarily easily adaptable to Lunos.

– Code minimum ventilation rates are higher than what I am intending to provide with my Lunos fans. I figure that additional ventilation will be created by bathroom fans and range hood (non-HRV, of course) such that I overall I should be fine for ventilation, but my dedicated HRV cfm from the Lunos will be less than the mandated code amount. This also plays into the fact that I would like to not leave them all on the highest setting all the time.

– It looks like BC code requires a CSA approval that I don’t believe the Lunos fans have.

It might be a long shot looking for somebody familiar with BCBC here, but I figured I would check. Thanks!

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  1. GBA Editor
    Martin Holladay | | #1

    If you are patient, Malcolm Taylor, a GBA reader who is knowledgeable about BC codes, will see your question and will probably post an answer.

    In the meantime, or if Malcolm doesn't answer, here's some advice: the best person to answer code questions is your local code authority (building official), because their interpretation is the only one that matters.

  2. user-1061844 | | #2

    You can set the controller for the lunos on setting 4 - which means it has 4 flowrates, but no off setting (9, 18, 27 and 35CFM) - this should satisfy the code requirement for not being able to turn it off.

    FYI We distribute the Lunos in the USA with, but not in Canada.

  3. Expert Member

    There are a number of ways to meet the ventilation requirements. Let me try and stick to those most closely related to the situation you describe.

    Each bedroom, and the living area need to be supplied with outside air at a rate determined by the code. You can't make up the amount you are below this number by supplementing it with the bathroom and kitchen fans as they are not supplying air, they exhaust it. So you need the Lunos to be able to run continuously at the required rate.

    Each bathroom and kitchen need to continuously exhaust air at a required rate. The only way I can see to use the Lunos exhaust cycle for this instead of the bathroom and kitchen fans (or the air returns in a centralized system) is to locate more Lunos units in the kitchen and baths. In other words, from a code perspective the Lunos exhaust capability isn't much use.

    The code assumes most systems will be either a central HRV or a supply only system that continuously runs the bathroom and kitchen fans as the exhaust component.

    The switching requirements are there so that if you use the kitchen and bath fans as your exhaust they also have a separate switch to increase their output when you want to use them at a higher rate than their continuous run function. The two switches are so you don't inadvertently turn off the fans altogether. I don't see a problem with the Lunos switching, but it is something to run by your BI.

    Crawlspaces can either be ventilated (supply and exhaust) or connected to the floor above with passive air grills.

    Hope this has been of some help. Feel free to ask more specific questions.

  4. Pascalli2 | | #4

    Great, thank you so much for the responses.

    Malcolm - I really appreciate your help on this. Would you be able to shed some light on these further questions:

    1. What is the code required cfm (or L/s) for a bedroom of approximately 169 square feet (or 1400 cubic)?

    2. I am planning on 5 pairs of Lunos fans, which results in a range of 45 - 110 cfm total (about 22-52 L/s). Every bedroom will have one fan, but not a complete pair. From what I can tell, I need either 35 or 42 L/s to meet code for the whole house (depends on how they want to count our spare bedroom). The code rates are attainable using the Lunos fans, but is there an issue with the fact that they could potentially all be turned to low and fall below the required rate?

    3. From your comments regarding bathrooms, am I correct in thinking that an eGo fan with a maximum continous exchagne of 12cfm (27cfm exhaust only) would not meet code requirements for bathroom ventilation? I had planned to use an eGo in our powder room (toilet and sink only - no shower). Does code specify a lower requirement for a bathroom that does not have a shower?

    4. Will I need to have my other bathroom exhaust fans continuously exhausting, even though they are not part of our primary ventilation system? It seems like a shame to be dumping conditioned air when the bathroom is not smelly or humid.

    5. Do you have any other thoughts or comments about using Lunos from a code perspective?

    Thanks again - I really appreciate it!

  5. Expert Member

    Bear with me, I'm out tonight but will get back to you by the weekend.

  6. Pascalli2 | | #6

    No worries - Since you are offering free advice, I am more than happy to take it on your schedule. :)

  7. Expert Member

    I'm not sure my first answer was all that accurate. The Lunos fall outside all the systems the code anticipates.
    Let me try again:

    Although they anticipate using the bath and kitchen fans as part of the ventilation requirements, you can also locate the exhaust portion of any system anywhere you want as long as you supply air to all the bedrooms and the common area. So you could argue that having Lunos in each location satisfies the requirements.

    The rate of required exhaust is determined both by the number of bedrooms and the floor area of the whole dwelling. You have to use a table in the code to determine it. (The rate of exhaust = the aggregate of the rate of the various supplies so you get a balanced system).

    I'm backtracking on what I said about the switching of the Lunos. It may be a problem if you can set them below the required rate. You would need something that kept them from going below that.

    As long as you have a fan or fans that meet the exhaust requirements, you don't need to have the kitchen or bathroom fans running continuously. If you do need them to make up part of the requirement, only the ones you need have to run, not the rest.

    Apart from the ventilation requirements there are separate ones for the fans in kitchens and bathrooms. The code doesn't seem to distinguish between bathrooms and water closet rooms, or whether they contain baths or showers. There are tables showing the required capacity in the same code section (9.32.3).

    All the relevant tables are here:

    Sorry if this is a bit scattered. I find it a difficult code section to interpret.

  8. Pascalli2 | | #8

    Thanks Malcolm, it is reassuring to hear that I am not the only one who finds the ventilation section a bit complex. It kind of seems like I am trying to fit a round peg in a square hole by choosing lunos here
    . While I think it is great that code is trying to address the issue of ventilation, it also seems to make innovation more of a challenge.

    I think it will help a bit if I ignore the fact that they are hrv as far as the city is concerned, as I think that simplifies some of their requirements. Ultimately, though, like Martin pointed out, I guess it will come down to city staff's interpretation and understanding. If they are flexible enough to acknowledge that the spirit is met, even if the particulars don't match code, then I am set.

  9. Expert Member

    "like Martin pointed out, I guess it will come down to city staff's interpretation and understanding."

    That's what has happened with both the rain screen and seismic provisions. They come in, get interpreted, and some modifications or clarifications are issued. Local building inspectors hopefully use their common sense in enforcement.

    The ventilation requirements haven't caused much of a stir among builders, largely because they came in at the same time as the new energy efficiency requirements, which, are much more difficult to interpret and have bigger consequences to the design process. Most builders are just leaving the ventilation to an HVAC contractor who installs whatever they usually do.

    One other out in the code is that single storey houses under 1800 sf can still use an exhaust only system. Don't know if that applies to you.

  10. Pascalli2 | | #10

    If I were more committed to responsible building, I would fall under the 1800 sq ft single storey exemption, but I'm afraid my approach is one of trying to compensate for my excess by minimising its impact.

    The energy efficiency requirements don't seem as tricky to me, but that is probably because I was already planning to exceed code in most of those areas. Hours spent onGBA helps, too.

    Here's hoping the city is collaborative instead of adversarial.

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