The RIGHT Way to Ventilate Your Building

Buildings nowadays are more airtight and commonly used types of ventilation systems don't work as they used to. Creating a healthy and comfortable indoor living environment begins with ventilating our spaces the right way. Without proper ventilation, we risk stale air, mold growth, harmful pollutants, even allergies, and a diminished quality of life. But out of all the available types of ventilation systems which one is the best for us and our buildings? That's exactly what we're going to explore.
✅ Are you an architect, engineer, or builder who wants to learn to design and build energy-efficient, healthy and affordable Passive House buildings?
👉 Click here to read more and become a Certified Passive House Designer/Consultant: passivehouseschool.com/course...
📞 Want to learn how you can start designing Passive House projects and become a worldwide accredited professional? Book a FREE discovery call with me - passivehouseschool.com/call/?...
----
My name is Anton Dobrevski and I'm an architect and accredited Passive House Trainer who is passionate about designing High-Performance and Healthy buildings. On this channel, I'll be talking about Building Science and the Passive House Standard, more specifically about Insulation, Airtightness, Vapour Control, Heat recovery ventilation systems, Thermal bridge-free designs, Fresh Air, Healthy Buildings, Comfort, Innovative Building Products, and I will show you around some of the projects I am working on. You'll also find videos revealing the thinking, the process, and the ideas behind the making of Passive House buildings. If you are an Architect, Engineer or Builder hit that subscribe button!
⌚️Timestamps:
00:00 Intro
00:45 The role of ventilation
02:36 Ventilation Type 1
04:36 Ventilation Type 2
06:23 Ventilation Type 3

[@cvetitoyoy]

Suuuper useful video! Thank you!

[@tealkerberus748]

As a matter of interest, for those of us who watch with cc on, the text you put at the bottom of the screen is completely covered by the cc.

[@AntonDobrevski]

Thanks for the feedback. I will have it in mind.

[@sofiapavlova3091]

Hey Anton, that`s again another very interesting video. So much to say on this topic but I will just highlight how important the air ventilation is especially for young people and kids. We experience nowadays an increase of developed allergies amongst these age groups.

[@AntonDobrevski]

Thank you! You are totally right - ventilation is crucial for creating a healthy living environment (especially with airtight buildings) and it can help with allergies but also prevent dry skin and respiratory problems.

[@vivenreddy]

Great content. Do you recommend vented or unvented roof?

[@AntonDobrevski]

Thank you! 🙂 If the roof space is heated, it is recommended to have ventilation and connect it to a Mechanical Ventilation with Heat Recovery (MVHR) system. This ensures a continuous exchange of air while recovering heat, contributing to both indoor air quality and energy efficiency. If it's unheated, it is still recommended to ventilate it but in that case, it shouldn't be connected to the heat recovery system. On the other side, whether there should be a ventilated cavity in the roof buildup depends on the buildup itself.

[@centerbuilder7677]

Anton, just went through a bunch of you videos. Thanks for all the information. I have a question. The ridge vent and the vent where the top of wall meets the trusses. 1. Is this good enough? Two doesn’t it defeat the purpose if I was to run 4-6” foam board insulation between the trusses. Pushing the heat out of ridge vent and the other vent. I know the moisture is the enemy. Can you elaborate?

[@AntonDobrevski]

Happy to see you are enjoying the videos. It depends on whether you want to have a heated (insulation along the pitched roof) or unheated attic (insulation on the ceiling). For unheated attics that’s not a problem as the attic will be vented with the outdoor air that will be getting in/out through the soffit and ridge vents. When you have a heated attic (where the insulation is between the trusses), then the attic space should be connected to the ventilation system of the building and the soffit and ridge vents will be used to only to ventilate the space between the insulation system and the roof tiles (sort of how a ventilated wall façade works).

[@centerbuilder7677]

@@AntonDobrevski my attic is not heated. One of my furnaces is sitting in the attic. Should I run insulation between the trusses and how many inches.

[@AntonDobrevski]

@@centerbuilder7677 If the attic is unheated and you are not planning to have any living spaces in it, then it's better to insulate the attic floor. The insulation thickness very much depends on the building location, size, design etc. and it is determined by making a complete energy model of the building in the PHPP software.

[@centerbuilder7677]

@@AntonDobrevski I’m planning on 18” of attic floor. But I was also going to insulate between the trusses. Is that not needed?

[@AntonDobrevski]

If you're planning on installing 18 inches of insulation on the attic floor, that should provide substantial insulation for your unheated attic (You can also check out my video "What's the BEST Insulation Thickness?"). This is generally the preferred method for unheated attics, as it keeps the heat in your living space below, not in the attic. Insulating between the trusses is typically done when the attic is a heated, livable space. However, if your furnace is in the attic, you might want to consider some localized insulation around it to protect it from extreme cold, which could improve its efficiency and lifespan. But broadly speaking, for an unheated attic, focusing on the attic floor insulation is usually sufficient and more cost-effective.

[@sofiapavlova3091]

I am quite curious what to consider by the choice between HRU and ERU. It seems to me that HRUs are more common in Europe.

[@AntonDobrevski]

HRVs are indeed more common and the slightly more affordable option. What should be considered when choosing one over the other are the climate conditions - if the outside temperatures during the winter are low, there is a high chance that the interior humidity will be very low too. And for these cases, we should use ERV which will maintin comfortable humidity levels indoors. The same principles applies for very hot and humid climates where we use ERVs not to bring in all the moisture from the outside. All in all, whether you should use an ERV or HRV should be determined based on an enedrgy model of the building using the Passive House Planning Package (PHPP). In this model are considered the climate of the location and everything that has an effect on the indoor relative humidity.

[@sofiapavlova3091]

Thank you, Anton. That’s very helpful to know. It so crucial for clients to choose the right sustainability consultant / architect.

[@Beeblebrox6868]

It's a very interesting presentation and I've learned a lot. However, I find the argument in favour of the speaker's preferred active system to be a direct betrayal of the core "passive house" philosophy. Designing a system like that is fundamentally not passive if it required active ventilation/filtering to work! It's just not good enough. You've mandated a more expensive, more technically complicated and breakdown-prone system that many will not be able to afford. I think the dismissal of the 2nd option, extraction ventilation, was not convincing and painted a misleading assessment of its benefits and drawbacks.

[@tealkerberus748]

Note that at the current accelerating rate of increase of carbon dioxide in our atmosphere, by the end of this century the air outside will not be useful for ventilating our houses. We need to be designing ventilation systems that will be able to be retrofitted with some form of mechanical or biological decarbonation and recirculation in order to provide healthy indoor air quality.

[@AntonDobrevski]

Additional filters/modules with filters can be added to the outdoor air duct of MVHR systems which can address this issue.