The purpose of vent air, from what I have heard, is to prevent the room from fogging up in the first place when you are cooking or taking a hot steamy bath or shower. A better test, I would think, would be how well the system prevents the room from getting all foggy from the moment the fog machine starts starts. If no vent air allows the room to get foggier and foggier over time and the vent air prevents it from getting foggier over time would be better proof of how allowing vent air.

I am fully impressed! It’s just a complete kzread.infoUgkxGqOCINHE0Z0E5gxzSdNi9NWGugRY5Hm2 plan with the best resources and step by step instructions . These shed plans are so satisfying as if the sheds build themselves on their own. Worthy work Ryan!

Funny story about Aprilaire: when I left commercial for residential integration, Aprilaire was the "Nest Thermostat" at that time (2006). I called support asking "How can I control a VAV box (Variable Air Volume)" and the support guy said "It's a HOUSE! Why do you need VAV?!" Fast forward to today: All the PH HVAC units are balanced damper systems with VFDs. I should have done product development sooner, but it is the market education rate that defines adoption rate. Thanks for Build Network Matt.

Great demonstration. Another reason for makeup air is safety - if you don't have it, the path of least resistance for incoming air is the water heater exhaust if you have a gas water heater. Air pulled from there contains carbon monoxide.

@CBBC435

3 ай бұрын

What about sewer pipe vents? Methane. I'm thinking that applies as well.

Great demo. My first career was HVAC for Pharmaceutical Research Labs where flow tracking is everything. It's used to create positive or negatively pressurized zones to ensure fumes go where they need to go and not into the researchers. And all this with amazingly high cooling/heating efficiency thanks to ERVs. This was back in 1988! Took this long to become popular in homes. LumenCache can power this level of MUA and EFs just fine, plus monitor the pressure differential.

The math at the end is the same that I use to decide which size pizza to get. Turns out, it is always the biggest.

We cook a lot and have a wolf setup with a 1500cfm exhaust hood. Just crack the window on the other side of the room and everything is good.

@TheBalognaPony

Жыл бұрын

This is the first thing that comes to mind.....open a damn window 😂

@typhoonjenkins8330

Жыл бұрын

I have a BlueStar 1200 CFM 42" Pyramid hood over our 36" BlueStar 6 burner range. I open the kitchen window too. The only problem is, we live in the midwwest and when we;re in the dead of winter, we freze our butts off. LOL In the last two house I had a 60" Garland full commercial with a 60 inch garland hood, and prior to that a 48" Viking Commercial (Black) range with a Viking 48" (vent a fan" hood. This BlueStar is easily the best of the 3. More powerful, able to run very consistently under super high heat and really does the job. BlueStar is the UL rated rated version of Garland Commercial stuff. I'd never buy another Viking again, that thing looked great, but it was a very low quality and flimsy unit back then. Hopefully they've made a bunch of improvements by now. BlueStar is my favorite brand, ever with the cheezee name, it's a beast

@stucorbett7905

Жыл бұрын

@@typhoonjenkins8330 We have the same problem in winter. Montana. I just put a sweater on while cooking. Problem solved.

@Chris_at_Home

Жыл бұрын

I put two 4” round ducts coming in under the floor in the basement and then in the wall up high one comes out in the laundry room and the other over the kitchen cabinets. The cold air won’t rise up in the pipe unless a fan is running. Our home is small but has double stud foam filled walls.

Thank you, Matt, for a great visual. In a future video, can you address post construction troubleshooting and repairs? I often wonder if a homeowner will know if the powered makeup air equipment (and ERV or HRV's) are working or need repaired? Now retired, I had only built a few custom homes (less than 3000 sq ft) and a lot of Habitat homes and had passive makeup air through the HVAC in north Texas for simplicity.

I believe that any system which is taking conditioned air out of the envelope (dryers, gas hot water heaters, bath fans, etc) should have the option to supply its own make-up air. I had a wood-stove in the 90's which had a separate intake pipe for combustion air so it didn't evacuate air out of the house. I wish more things were designed with this level of thought.

@randomrazr

Жыл бұрын

would an air exhcnager do that

@gibblespascack1418

Жыл бұрын

If you had an EPA certified wood stove, your house would leak enough to supply the wood stove and the required air in a controlled EPA certified wood stove would not be the same as a pre EPA wood stove. With the outside air supply, you are cooling the wood stove and it does not burn as clean as it could, if the air was RT. So you are losing heat through smoke instead of burning those combustibles in the smoke(when using an EPA certified wood stove). If you had an air tight house, an ERV would be a better option from an efficiency standpoint.

@randomrazr

Жыл бұрын

@@gibblespascack1418 what about HRV?

The custom makeup air built into the fumehood is cool. Biological safety cabinets work with a similar principle - air is fed from the top of the work surface and gets sucked in at the back, and gets recirculated through a filter. Everything in between exists in an isolated filtered air envelope (laminar air flow).

You can also add a Shelly smart switch to damper so when it’s turned on it will tell another smart switch controlling make up air fan to turn on

As I replace doors and windows on my 1952 house, do I need to think about adding make up air somehow? Talk to my hvac when my furnace craps out?

So he's correct I have a 350 cfm hood vent when it's on med or high it starts pulling air from my attic door on the other side of the house, my next project is to get that door to sealed better and some how add make up air to my house I'm trying to keep roofing penetration to a min

Me visiting Austin keeping my eyes peeled for real celebrities like Matt Risinger. 👀

Flow is by the fourth power of the radius (assuming laminar) or higher if not.

Have you ever tried AirScape's Make Up Air system? It's 1600 cfm capable and based on pressure.

I have to ask the question.... How much money do you need to spend to make a "tight" house(upfront)? Just to turn around and spend more money on a make up system? VS.... The products that you're being paid to promote?

There is a local restaurant in town that has no makeup air and a monster hood vent. The reason I know is when you go to open the front door, the suction is so hard that a child probably could not open it..

If your kitchen is actually a room (with a door) instead of a bunch of cabinets and appliances arranged in your living/dining/family room…superior performance will be achieved

@georgewelker853

Жыл бұрын

And even if it’s not a room you’ll have a ton better performance than without makeup air. Depending on how you route the makeup air you can essentially use the hood as a central exhaust system and it’ll pull air from around the entire building and it’ll do an amazing job of letting your exhaust work super efficient

How about a downdraft-style EF backsplash with MUA side or front vent? Anyone doing that?

Very difficult to get efficient and complete exhaust of vapors from cooking. Ask anyone who works on commercial food service equipment, which is almost always in a setting with a makeup air/exhaust scheme.

Idk do the filters take out the smoke if the smoke is outside? We have alot of grass fires here in Oklahoma and Kansas. Seems like more crap to maintain and increases your electric bill. I just open the window when I know there isnt crap in the air outside and run my attic fan

@julianopificius6910

Жыл бұрын

If just opening a window is a suitable solution for you, then no, you don't need all that "crap", but we don't all live in Oklahoma. The powered, heated make-up air system I bought from Fan Tech also includes a filter.

Probably make more of a difference to clear the smoke if the make up air was at floor level

I want to see the blower door test on that tiny house.

Which trade takes care of helping create makeup air for a kitchen hood? Electrician, HVAC, GM?

@KPCKeysDIYBuild-Install-Fix

5 ай бұрын

HVAC

What should current homeowners do without installing this makeup air? Just crack open a window when turning on the hood vent?

@CT_Taylor

5 ай бұрын

yes

Is there any reason why the vent hood and make up air need to be a separate system? Couldn't you just duct it all to the ERV and not have to worry about evacuating the conditioned air so much?

@scp8412

Жыл бұрын

That’s what I was thinking too. But realistically ERV should cover that, not sure it needs making up air? 2 other options: -Would be cool to see how much extra air an ERV brings in with change of pressure of a big fan being used. -wire ERV boost mode to the fan?

@TrytoCatch22

Жыл бұрын

2 reasons I can think of: 1. There is grease and other contaminants you would not want gumming up your ERV exchange filter. 2. Most ERV capacities are nowhere near the CFM needed for a proper hood vent. ERVs are 150-250 and hood vents are 600+. You would have a huge imbalance. I think it would be a GREAT idea if someone could combine the two though. If I could steal Matt's phrasing. That would be "bomber" lol

@brymidrif

Жыл бұрын

I agree with Catch here in the comments. Another issue about the grease is, if there were ever a grease fire, flames that come from the cook top, or some other source, moat jurisdictions have the venting duct in a heavy enough gadge metal so that it will allow a 30 minute burn inside of the pipe before it eats through the metal and into the structural members of the home. ERV's are not meant to accept this kind of exhaust air too because of the micro oils formed when cooking!

@scp8412

Жыл бұрын

@@brymidrif Yeah obviously not to suck range hood air, I think we were saying the ERV is already the fresh air intake and would equalize the home slowly back to normal or go into a boost mode white the hood fan is exhausting air. All that without needing more systems in a house.

@TrytoCatch22

Жыл бұрын

@@scp8412 unless you get a super beefy ERV (or multiple ERV's) with the capability to do "intake only" mode and have the ability to match the cfm of the vent hood exhaust, you would still get pressure imbalances. If you equalize slowly, at some point those pressure imbalances would cause your vent hood to start struggling to exhaust what it is designed to remove because there is not enough air replacing it from the ERV setup.

I've never seen air so pretty!

@buildshow

Жыл бұрын

Ha! Thanks for being 1st!

I usually just open one of the kitchen sink windows., I get it, automation. Can then control it on their silly phone? I get it, younger generation will eat that up. Great Show.

This looks like a state fair booth... A doghouse with glass windows flowing smoke to make people go, oh and ah! It cleared the air in the doghouse so fast! What about houses with staircases and multiple levels where air will get trapped in pockets?

Anyone has link to the video Matt is referencing?

@vitaliypenkov

Жыл бұрын

I think that's it: kzread.info/dash/bejne/ea2kyplrj9yep7Q.html

Isn't 22 the same upside down as right side up?

@swtravels

Жыл бұрын

Yea! I was looking for somebody to say that. 😂

Make up air can be dropped in front of and in back of the range, and just make the hood a few inches wider than the cook surface. Let the hot air rise.

Is there any reason to have makeup air for bath exhaust fans in a reasonably tight house? I plan to have an ERV for fresh air, but most ERV manufacturers still recommend bath fans. Maybe it’s not necessary for just one exhaust fan, but what if two or three are running at the same time?

@frqnj

Жыл бұрын

What’s the cfm for the bath fans?

@julianopificius6910

Жыл бұрын

The answer, as always, is "it depends". Obviously with a tight house the actual extracted volume will be less than nominal for the extractors, especially if you operated them concurrently. This may be only mildly inconvenient to you, as it'll take longer for your bathrooms to clear; BUT: if you have "feeble" combustion systems like a simple wood burner or a gravity- vented gas water heater you could pull combustion fumes back down the flues into the house with both bathroom extractor fans running. That can be dangerous. You should look at your local building codes, as houses built in different years have different code requirements. In general, all the states in the union have a requirement for separate makeup air (i.e. in addition to your passive combustion air inlet) when you have combustion devices with un-powered vents AND a range hood of 400CFM or greater. (In Minnesota, where I live, the threshold is 300 CFM.) I recently purchased a range hood rated at 950CFM, because I like doing "high energy" cooking, like steaks and stir fries. I assure you we don't simply open windows in mid-January to let in "fresh" air... One episode of that technique won me my wife 's approval for the expenditure for the make-up air system _real_ quick :-) so... The hood cost me around $500, but the heated, filtered, variable speed fan-assisted makeup air I need in order to be able to USE the range hood cost me $2500 !! Anything is better than depositing cooking grease all over every surface in the house, though... Additional info: My make up air system came from Fan Tech. It ships with a sensor to detect extractor fan motor current to control the make-up air fan: once calibrated it would balance the air pressure, but I'm upgrading my fan speed controller to be fed by a true pressure balancing system with my own custom system. Hope all that helps.

@wesleywahl9675

Жыл бұрын

@@frqnj this isn’t determined yet, but I suppose they will be in the 80-100 cfm range.

@wesleywahl9675

Жыл бұрын

@@julianopificius6910 the only combustion appliance other than the range will be a direct vent fireplace. This isn’t a concern since it’ll provide its own fresh air. I have already spec’d the Fantech makeup air system for our range hood, so we should be good there. The ERV will be ducted to extract from each bathroom. Hopefully this will be enough in addition to a low performing bath fan to remove moisture in a sufficient amount of time. My solution so far if it doesn’t is to add a 120v switched damper to the bath fan switch and run it through a filter box for passive makeup air. I was hoping to avoid this if possible though so I don’t have unnecessary penetrations in the exterior envelope.

Our system is so blocked by a crappy louvered outlet (against manufacturer instructions) and too-long flex duct.

Fogging the hutt... Lol That's what Luke Skywalker did....😂

That’s a lot of foggin’ work for a great demonstration.

Reminds me of my college days

@scottwilliams6257

Жыл бұрын

Cheech and chong may have given a better demonstration but I get the point. "I think we're parked man"

It seems somehow wasteful to have an erv and hood makeup air in one house. How much more to just upsize the erv to handle it?

@D2O2

Жыл бұрын

Can you even find an ERV to provide enough flow for a range hood?

@mitchdenner9743

Жыл бұрын

Erv/hrv's are not meant for kitchen exhaust, they would clog up and stop running in no time from the grease. Thats why commercial exaust systems are made from heavy black iron ductwork and wrapped with fireproof insulation due to the possibility of grease fires. And they need to be cleaned regularly.

@mitchdenner9743

Жыл бұрын

@@D2O2 yeah, they make them big.

@D2O2

Жыл бұрын

@@mitchdenner9743 How big? Residential units top out in the 200 CFM range, maybe some newer models slightly larger, but not big enough for a range hood in the 500+++ cfm range.

@mitchdenner9743

Жыл бұрын

@@D2O2 as big as you need, most all of the manufacturers offer from 200 up to 75,000 cfm units, whether or not they consider them residential or commercial is irrelevant, if you have the electricity to run it and can afford it, they have it.

Or, save your money and crack open the kitchen window when using the hood.

@CBBC435

3 ай бұрын

I'm thinking that's what I'll do.

@aaroncedillos8663

Ай бұрын

Interesting you say that. I said the same thing, and the response was “you won’t be cracking the window when it’s 100*f outside”. Curious if makeup air brings in hot air.

@PlumberGuy-ez9wx

Ай бұрын

​@@aaroncedillos8663Of course it brings in hot air, cold air too. Some units have pre heaters.

@jefftee448

13 күн бұрын

Yea right....I'd like to see the rest of your family not roll their eyes and ignore you when you try to convince them to open the window every time they use the kitchen or bathroom exhaust. But depending on your setup, a lot of the make-up air ventilation systems the air is cooled, filtered and dehydrated before its put back in your house.

22 upside down is still 22

@julianopificius6910

Жыл бұрын

66, on the other hand...

Ugh… Pluming is complicated, but it’s got nothing on HVAC. Correct me if I’m wrong, but putting together HVAC + Dehum + Make-up has got to be the most difficult problem in residential construction.

@buildshow

Жыл бұрын

I agree with you

@julianopificius6910

Жыл бұрын

@@buildshow and Jack Maher, be careful with local codes: in cold climates like the upper Midwest they won't let you vent fresh, untempered air straight into the return side of your HVAC system. In that case, make-up air must be completely separate. I'm in Minnesota, and had to look all that up for my system (Fan Tech).

@kc9scott

Жыл бұрын

@@julianopificius6910 Why not? Is it just because most people would be unaware/uncaring if there was a malfunction causing excess fresh air and energy use?

Seems like it would make most sense to have an ERV/HRV dedicated to all occupied spaces and bathrooms and then have a separate makeup air system that was interlocked with a kitchen vent hood. For cold climates however, makeup air without heat recovery would probably not make sense. In that case I would like having a branch of ERV/HRV system on a damper that opens when the kitchen vent hood activates that also triggers a boost mode on the HRV/ERV would be the best approach.

@wesleywahl9675

Жыл бұрын

But isn’t an ERV balanced? So it still wouldn’t be able to equalize the pressure differential between the house and outside.

@julianopificius6910

Жыл бұрын

@@wesleywahl9675 Some ERVs have fresh air input capability, but that's typically only about 150CFM, so it only works with low-flow hoods - 300CFM or less.

Your demonstration seems like common sense. I know some physics but little about exhaust fans. But if you have an exhaust fan unit that could measure exhaust cfm and the unit knows its unrestricted cfm ( in your demonstration 32 CFM ) , if the exhaust cfm goes below it , the unit communicates with a damper to make the adjustment. In this case if you had the exhaust fan on but had some windows open there would be no need for makeup air from the damper. Perhaps I just described something on the market

@julianopificius6910

Жыл бұрын

You can't just open windows in winter in cold climates :-)

What if the makeup duct is mounted further away, upstream of the hvac rather than so close to the blower? Will I still see a benefit?

@mitchdenner9743

Жыл бұрын

Yes, but the closer the better. Remember its pulling in outside uncondioned air , and also pulling out your conditioned air from your home. You really want to short circuit the path of make up air to the hood.

@kc9scott

Жыл бұрын

I disagree about the goodness of having the makeup air outlet really close to the vent hood. IMO you want the smoke-producing item (i.e. the range top) to be located between the makeup air supply and the vent hood. Otherwise, the vent fan will just be exhausting the makeup air while the smoke still stays in the room.

Interesting 😅 👌 👍

Belinda Carr has some great videos on foam vs traditional insulation, and how R value testing ignores the fact that foam takes more than 24 hours to reach steady state, where fiberglass is much less. 1 inch of foam is more like R20 than R4.

Just crack a window for fs sake....😂

@ThePentosin

Жыл бұрын

im guessing its not very cold where you live.

Why wouldn't you over pressure the house to clear the air out of the house so you can control where your fresh air comes from and I would think run it through a Energy Recover system, to keep as much cool or warm air in the house.

@julianopificius6910

Жыл бұрын

Because cooking fumes will be circulated all over the house, depositing airborne grease everywhere.

Whose family gets to keep the dollhouse?

@buildshow

Жыл бұрын

Happy to give it to you!

@mackfisher4487

Жыл бұрын

@@buildshow got me, I have no daughters a

A similar thing happens when you are running, a wood, stove or fireplace that does not, repeat, does not have an outside air source for combustion. The heated air goes up the chimney and it pulls the outside air into the structure. If the wood burner or fireplace has an outside air source, you’re not losing heated air up the chimney. I realize that some fresh air coming into a structure is not a problem but if your only source of heat is from wood, it does make a difference.

Only Matt Risinger would have makeup air on a dog house 😅

super cool idea and one of those common sense things that has been ignored for decades.

Ah yes, a hotbox

"looks like we are pulling about 22 cfm.... remember we are reading it upside down" ah right... so it's 22.... instead of ↊↊... 😅😅

This guy doesn’t know anything and is just a salesman.

@julianopificius6910

Жыл бұрын

Yeah he does; he's a bit imprecise on some of the physics details, but he's sound. Making videos presents a difficult balance: if he were to get too far into the weeds, he'd lose some of his audience. You can always do a bit more research if you want to get more precise info. The important takeaway is that extractor fans can't work if you don't replace the air they pull out. You can do that with cracks in the walls, an open window, a simple vent and damper, or a filtered, ECM fan driven, heated system, depending on where you are and how much air you're pulling out, but the basic fact remains: what goes out must be replaced by something coming in.