Can your home be too AIRTIGHT???
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- čas přidán 11. 09. 2024
- Air tightness is actually really critical. It impacts all aspects of the health and comfort of a building. In this video we talk about air tightness targets for new homes, with gas appliances, all electric and homes with a centralised or decentralised heat recovery ventilation systems. How air tight should all these homes be? Can your home be too air tight?
For any questions don't hesitate to contact us.
www.efficiencymatrix.com.au
www.energyleaks.com.au
Build it tight, control it right.
another variation is "build it tight, ventilate it right"
@@joshuahayes6672 Possibly the one you provided is original
All new buildings and remodels need to be air tight in order to be more comfortable and energy efficient.
Air sealing, super insulation, triple pane windows, energy efficient heating and cooling systems, energy efficient appliances, set back thermostats, LED lighting, solar panels with battery storage and a 220 volt outlet for an electric vehicle charger all need to be considered as part of the build or remodel. Solar panels with battery backup can now be your buildings back up power when the utility power goes out. No need for a noisy fossil generator.
Interesting video guys, Im looking to do a Passive house build so this makes me feel alot better
That's an air leakage of 0.6 !!!
This man talks about a leakage rate of 7, holy moly......
@@mirola73 I'm well and truly into my build since this comment and detailing air tighness is tricky but I am getting there. 0.6 shouldn't be an issue to get
Hope so!
How do you build air tight with gas heating ? And gas appliances
Even if your home is not airtight, gas appliances need ventilation. If there is no wind, how can you be guaranteed that you have enough ventilation, with a leaky home?
Why would you suggest a gas *ducted* heater have an ACH of ~7@50Pa? The combustion source is outside so no danger of CO buildup. For a gas wall heater, that’s a different story.
To clarify; I’m retrofitting a 1990s home with induction cooktop but gas ducted heating, and aiming for 5 ACH@50Pa.
Shaun Ruigrok Well actually, on some old homes with an old ducted heating system, there were a couple of situations where CO was being emitted from the outlets, while the ducted heating system was running.
Efficiency Matrix Oh wow, interesting, I had not heard of this. I don’t have a CO sensor, I might just get myself one now and check… assuming we’re getting a reading of
The house does need to "breathe" you are actually just saying you want to control the "breathing". Your energy recovery ventilation unit is like a bionic lung for the home that is probably more efficient than the old school home.
WRONG WRONG WRONG WRONG. Thank God someone is taking about this. Nobody in America is gonna know how often or when to open their windows for fresh air, nor will they want to. You do NOT want an air tight house. You want an air tight ceiling, and an air tight floor, yes, but your walls should not be air tight... they should be weather tight and condensation resistant. You can not ignore the fact that there is a huge 3' x 7' flap called a front door. You must allow for the people to open and close this flap quickly many times per day. If your house is very air tight then you will surely break through this envelop when you use the front door repeatedly. The problem is that you will not know where this break will happen and it might happens in an unfavorable location. We must focus more of our time and money on other factors that affect energy efficiency and comfort. Stop wasting time on trying to make a home very air tight and then managing the flow mechanically.
How air tight is very air tight?
In this video we talk about an air change rate of 10 @ 50Pa. In relation to your concern about the door opening, do you mean that if the building is completely air tight, you won’t be able to open the door inward and outward?
@@ecoevo You are talking about an air exchange over the course of one hour or one minute, but when you open the front door you are immediately displacing a large volume of air, which will surpass the 10 @50pa by a large amount and break through the weakest point in the envelope. In a real-world scenario, a household of people including children will open and close the flap (entry door) quickly and frequently, damaging one or more points in the the envelope. It may even happen in a location where the ceiling meets the attic. This can draw in fiberglass dust and heat, and maybe nobody will ever know it's happening.
The air that a typical entry door can displace can be calculated with a simple geometric equation of 1/4 * πr² * h where r is 3'and h is 7'. The displaced air volume is ~49.5 cu. ft. A typical house has a floor area between 1300 sq ft and 6000 sq ft. Using the more conservative assumption of 1300sq ft with an 8'ceiling (if you have a door 7' tall, you at least have an 8'ceiling), the internal house volume is 10,400 cu. ft. The volume of air displaced by the door is less than 0.5% of the house volume, I cannot see how would you experience any problem opening the door when the house has 10ACH @ 50pa. To be honest, purely by the compressibility of air can cater for this 0.5% volumetric compression.
In regard, to fibreglass dust and heat, these are the symptoms of a draughty, non-airtight house. Where do these unwanted substances enter the house? They enter via the air leaks.
@@ecoevo I appreciate the response, and you are almost correct, but you are missing a couple of factors, ie: velocity. A quickly opened door will draw more air than a slowly opened door. Also you are not realizing that the force required to compress that much volume of air is greater than the force required to rip open a piece of tape or a bead of spray foam. In my retrofit building practices, I do not air seal around the exterior walls/doors/windows. I'm my region, the allowed amount of air replacement for new construction is about equal to the area of a microwave oven, but this is not enough. By leaving room for a little air (not water nor condensation build-up) but slow moving air, to enter the home in a controlled way in a favorable location, I ensure the integrity of the other air-tight locations, whilst allowing any person of any age or range of knowledge to inhabit the structure, without any operating issues with their appliances, vents, fireplaces, etc.. Furthermore, their energy bills are virtually the same because they are not paying to operate fresh air fans... additionally, they will likely get more life out of their appliances, and their dwelling with LESS maintenance and repair costs overall.
I just wish the politicians would stop interfering, and allow us the ability to make smart decisions.