http://greendreamgroup.libsyn.com/this-house-sucks-but-not-very-har...

Check out this interview with brilliant scientist Brett Singer (seriously, he's a genius) from Lawrence Berkeley National Laboratory on our misconception about worst case CAZ Depressurization testing.

Tags: bpi, brett, case, caz, podcast, singer, testing, worst

Views: 1373

Reply to This

Replies to This Discussion

Even when gas stoves DO have exhaust fans they capture a small % of the combustion products. Note when a boiling pot is on the outside burners, most of the steam bypasses the exhaust hood. Inside burners get more of the exhaust. Even with 250 CFM the face velocity is way to small to capture all that much. 

solution - stoves need to be enclosed on three sides. NO one makes a stove like this but they should. This will more than double the face velocity an improve capture. Stainless side panels would do it and also eliminate splattering on adjacent counter tops. 

Good point. Now, assuming all of us here agreed, whom do you think we will win over first:
Appliance manufacturers or my wife?

Decades of experience in the Culinary realm give me a slightly different perspective.  It is the capture area of the hood that is of significance.  Installing sides will never go over, but if the hood were required to extend some predetermined amount beyond the cook surface and coupled with an appropriately sized fan motor, I believe the dynamics would fall into an acceptable range.

Hi Jim, just to add to your example from another perspective, a capture hood should also be more than a flat surface with an exhaust hole in the middle and skirting around it.  Take for example the fireplace industry that has to produce a draft without the fan.  By tapering the combustion chamber up to the flue there is a gradual acceleration of the air flow and less turbulence.  I suspect a little more air flow engineering as opposed to aesthetics would add to the effectiveness of hood design.

We must remember that the fan is not pulling the air from above the cooking surface up into the exhaust, just creating a low pressure zone in the vent so that the surrounding higher pressure can push all of that air into the little hole (just like a fireplace).

Bud

Actually engineering the flow would make sense. Maybe they need to attach the hood to the pot lid; now there is totally new paradigm.  Air jets blowing upwards around the edge of the cooktop would help also. After all that, there is still a need for some reasonable velocity to contain the products of combustion on the gas stove, the steam and smoke.  Apart from adding more flow, we haven't progressed at all in kitchen exhaust. 

Lizzy bought one of those NuWave induction stoves.  I've always hated electric and loved gas.  

I guess I have bias against induction that I wasn't aware of because even though there are all types of reviews raving about induction, experiencing it in person left me shocked.  (And I try to be open to having my schemas disrupted!)

In my mind cooking with gas is done.  If you haven't tried induction cooking, try it.  If you have tried it, and see any reasonable argument FOR gas, I'd be interested to hear it. 

Very interesting. Brett did a good job of explaining complicated subject and boiling down (pun intended)  points.

my favorite was "If you are going to do test that is going predict an unlikely event will happen then you need to do allot of monitoring to see if this event will happen"

I do not think we will see any changes anytime soon for CAZ but the podcast was a good refresher on the dangers of the gas stove top that I can take forward. I am glad that cfm in still equals cfm out

It also brings forward to me the need for mechanical ventilation. Many problems can be eliminated through dilution.  A good balanced ventilation system designed for the applicable climate is still one of the best things we can recommend for any home.

Good stuff

RSS

Featured Forum Discussions

Too many BTU's. Too much horsepower?

Started by Steve in General Forum. Last reply by Eric Kjelshus yesterday. 4 Replies

Stack/wind pressure and flow networks.

Started by Daniel James Grundy in Training. Last reply by Daniel James Grundy on Thursday. 5 Replies

BDT with vermiculite in hollow CMU walls?

Started by Brad Cook in General Forum. Last reply by John Nicholas on Thursday. 2 Replies

Strange IR Image

Started by Larry Nissman in General Forum. Last reply by Brad Cook Mar 9. 7 Replies

Videos

  • Add Videos
  • View All

Latest Activity

Eric Kjelshus replied to Steve's discussion Too many BTU's. Too much horsepower?
"Its more about run time with high RH removing, than to large over sized AC unit, in houses.  …"
yesterday
Sarah OConnell posted a blog post

Crowdsourcing for Innovation

Share Your Ideas!Novel Building Envelope Design for Increased Thermal PerformanceIn 2014, more than…See More
yesterday
Colin de Paor is now a member of Home Energy Pros
yesterday
Walter Ahlgrim replied to Steve's discussion Too many BTU's. Too much horsepower?
"The 5 ton system you have is not 500 hp racecar engines they are 500 hp truck engines. The duct…"
Friday
Daniel James Grundy replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"So I wanted to start with a basic who can help then go into more detail later. But yes find…"
Thursday
Daniel James Grundy replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"My tutor got back to me and while areas don't quite feel right a little to much assumptions…"
Thursday
Brennan Less replied to Daniel James Grundy's discussion Stack/wind pressure and flow networks.
"Daniel, I'm assuming you're trying to predict the airflows through the different openings…"
Thursday
Martin Newmark joined allen p tanner's group
Thumbnail

Energy Auditing Equipment for Sale, Trade or to Purchase

Discuss the pros and cons of the equipment you are interested in prior to purchase. Post equipment…See More
Thursday

Home Energy Pros

Welcome to Home Energy Pros – the unique digital community by and for those who work in the home energy performance arena.

Home Energy Pros was founded by the developers of Home Energy Saver Pro (supported by the U.S. Department of Energy) and brought to you in partnership with Home Energy magazine.  Home Energy Pros is sponsored by the Better Buildings Residential Network. Please honor our Guidelines

© 2017   Created by Lawrence Berkeley National Laboratory.   Powered by

Badges  |  Report an Issue  |  Terms of Service