PLN Posted August 10 Report Share Posted August 10 My wife and I are renovating a house with a big empty basement (35' x 90'). (poured concrete walls and floor) Up until now I've been using a kiln at my local maker space but I've bought a new Skutt KM-822 and my electrician has set up the wiring for the kiln in a spot out in the middle of the floor, about 7 feet from the nearest wall. I've also purchased the Skutt EnviroVent ducting system and extension kit. Delivery of all these is pending. My question: I have no immediate plans to fire above cone 5, but that kiln is capable of going to cone 10, so someday I might get ambitious and try porcelain or something. How HOT does that 3" flexible ductwork get if the kiln is running full-blast? Since that flexible ducting will be running across the floor and up a wall I wanted to build a little ramp over it to minimize tripping risk. Thanks in advance! Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 10 Report Share Posted August 10 (edited) Good question. Our fan exhaust is warm enough to clearly indicate that it is working*, but nowhere near a burning (touch) hazard. When I checked (first run), it reached ~125°F at the duct end. No doubt it will be hotter now that I've a) shortened the duct and b) it's almost that hot outside! !! That said, my suggestion would be to carefully monitor your duct as the kiln heats up to peak temperature the first few times. My kiln vent setup pulls from two small holes in the kiln's bottom plate; the rest** from adjustable vents in the "plenum" (sheet metal box that fits up to the kiln and where the duct connects). With the adjustable vents wide open, the system still pulls from the kiln, but weakly, so I closed them until the fan struggled, then opened them until it sounded happier. Check back for input from other Forum members... If there's a way to run the duct up/over, might be well worthwhile to eliminate the tripping hazard. *The smells also provide a clear indication that "it's working" - the various clay smells, burning wax resist, et cetera. **Most of the air comes through the vents. Provision for "make up air" would be important - air coming into the basement to replace what's being pushed out. Edited August 10 by Hulk movin' roun' Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
PLN Posted August 10 Author Report Share Posted August 10 Yikes! I was just now informed that Skutt is telling distributors that the Envirovent is back-ordered to April 2025! That's not what I had in mind when I said my order was "pending" above. If I have to jury-rig something for a downdraft vent any suggestions where I can see a design for a safe, reliable, easy to make system. What does the attachment on the bottom of the kiln look like? Quote Link to comment Share on other sites More sharing options...
Bill Kielb Posted August 10 Report Share Posted August 10 (edited) I usually advise folks to limit the temperature of the duct to about 120 degrees f for many reasons including fan and duct lifespan and 120 degrees is hot to the touch but not scalding.To do this mostly room air is removed and a tiny bit of kiln air. The room air is generally from several 3/4” holes provided in the mixing plenum or supplied pickup and the kiln air comes from several small holes drilled into the kiln. (Usually 1-4 prox. 1/4” diameter holes). The fans used are usually externally cooled and range prox. from 50 - 140cfm (rated in free air, no ductwork) The reality is they draw prox 1/10 that amount of rated air, they are starved on the suction side so no way to make their free air rated flow, just a fraction of it. Instead they maintain a very small negative pressure inside the pickup plenum which withdraws hopefully the right tiny amount of kiln air and mostly room air. Since the fan is so starved, they cannot cool themselves unless they have an external fan built in for cooling the fan motor. Other fans can be used but the designer must provide another positive fail safe path for air to keep the fan cool. One such design is here, but the caution would be to have a reasonable understanding of airflow before doing this. Old video: https://youtu.be/etpa2Pc9Hug?feature=shared Anyway, measurements of actual airflow were taken from an existing system to improve upon its design which included a non operable above kiln pickup to ensure everything stayed cool and to intercept wax burn off which many of these are not entirely capable of exhausting. FYI - a picture of a kiln pickup below showing room air inlet - this model does not have a shutter for adjustment. Edited August 11 by Bill Kielb Rae Reich 1 Quote Link to comment Share on other sites More sharing options...
Hulk Posted August 11 Report Share Posted August 11 (edited) PLN, You may have luck finding a retailer that has an Envirovent 2 in their stock, or, you might consider the setups offered by other vendors, e.g. L&L, Orton, Bailey As for DIY (do it yourself) design and assembly, some who have tried building up their own have posted their ideas. I'm still running an inexpensive duct fan/booster, where the motor is within the duct - I didn't expect it to last this long! When it fails, I'll replace with a fan that houses the motor out and away from the inside of the duct, and hence, may last better, not being directly exposed to fumes. Perhaps like this one, except with a higher ambient temp rating, for there are many days here > 104°F 3 7/8 in Wheel Dia, Direct Drive, OEM Blower - 1TDP7|1TDP7 - Grainger ...I'm not finding the pages I'd liked when putting my setup together. Here's some that have pictures and ideas How to Make a Downdraft Kiln Vent : 8 Steps (with Pictures) - Instructables Diy Downdraft Vent - Studio Operations and Making Work - Ceramic Arts Daily Community Diy Kiln Vent - Equipment Use and Repair - Ceramic Arts Daily Community There are more out there. Having a way to adjust the amount of ambient/room air (drawn into the plenum) is a big plus, imo. Edited August 12 by Hulk adjustable! Quote Link to comment Share on other sites More sharing options...
Denice Posted August 12 Report Share Posted August 12 I use a flexible duct that is metal not plastic like the ones for dryers. The only store we have found it at is Menard's, the duct got brittle after using it for 10 years and had to be replaced. I fired a kiln in a basement with no windows or ventilation system. This was before the Enviorvent systems were manufactured. I would find something else to do and only go to the basement to turn up the kiln. Denice Quote Link to comment Share on other sites More sharing options...
neilestrick Posted August 12 Report Share Posted August 12 On 8/10/2024 at 1:25 PM, PLN said: but that kiln is capable of going to cone 10, so someday I might get ambitious and try porcelain or something. No need to go to cone 10 for porcelain. Just get a cone 6 porcelain. You can use any brand of vent downdraft vent on your kiln. The Orton vent is the most similar to the Skutt. The L&L will work, too, but you'll need to mount it to the side of the kiln. All of them work the same way- they pull a little bit of air from the kiln and a lot of air from the room, which keeps the air in the duct cool. It should never be any hotter than a clothes dryer. No special ducting is needed since it doesn't get very hot. Quote Link to comment Share on other sites More sharing options...
Pyewackette Posted August 13 Report Share Posted August 13 The cone 6 porcelains that I've seen cost over $70 per 25 lb bag (compared to around $50 for the cone 10 stuff). Just FYI. There are these also, spendy but as far as I can tell very very efficient, also removes heat from the area as well as fumes and particulates: Vent-a-Kiln You may need an air intake for proper operation. Quote Link to comment Share on other sites More sharing options...
neilestrick Posted August 13 Report Share Posted August 13 2 minutes ago, Pyewackette said: The cone 6 porcelains that I've seen cost over $70 per 25 lb bag (compared to around $50 for the cone 10 stuff). Just FYI. Where are you getting those prices? For comparison, Standard sells their cone 6 grolleg porcelain (#365) for $2.33 per pound at the highest price. Buy 500 pounds and it goes down to $1.65 per pound. Their domestic porcelain (#213) for $0.96 per pound at the highest price. Laguna/Axner and Highwater have similar prices. Quote Link to comment Share on other sites More sharing options...
Pyewackette Posted August 14 Report Share Posted August 14 (edited) @neilestrick Sheffield Pottery Supply. I don't think I can try to buy more than 500 lbs at a time, I couldn't unload it all in any reasonable amount of time even if the vehicle can carry it. It's from a company I'd not heard of before. https://www.sheffield-pottery.com/collections/porcelain-clay?view=search#/filter:ss_filter_firing_range:Cone$25206/sort:ss_price:asc The $54 option wasn't there a few days ago (when last I checked) but on the other hand the $77 option, while I remember it being over $70, I didn't remember it being THAT much over $70. They apparently totally changed their website the day after I last logged in, they had to delete my account and give me a new one because it bolluxed up so much I couldn't sign in any more. Anyway. You get $5 off per 50 lb if you get at least 500 lbs. Still spendy. OH! I see what I did there! I meant per 50lb box, not 25lb bag! Sorry! STILL SPENDY though. I had compared Bailey for stoneware and they seemed about on par (both Bailey and Sheffield will be drivable for me once we get moved), I guess I didn't check porcelain because it seems porcelain is not as expensive there. But yeah, the porcelain at Bailey is a bit cheaper. https://www.baileypottery.com/store-dept-clay-chemicals/store-moist-clay/mid-range-clay/store-moist-clay-mid-range-porcelain.html?product_list_order=price Don't get too excited over the first 3 listings @ $38 per box. Their "box" is 44 lbs. Comes out @ about 77c per lb, from a company called "Taylor's". Haven't heard of them before either. Bailey's doesn't give a 500lb discount anymore, but you do get a discount of 5% at 250lbs. Don't know if that's the same as the discount you used to get at 500 lbs or not. The breaks are at 250 lbs (-5%), 1000 lbs (-10%), and 3000 lbs (-15%) now. The cheapest standard cone 6 porcelain at Bailey's is $51 per box ($1.02 per pound). That's the 213. I guess 6c per pound markup is not all THAT much in the general scheme of things but I was going by Sheffield anyway, and the cheapest I saw there a few days ago was the over $70 per box stuff. Highland is a 10 or 12 hour drive from where I will be living and I didn't find anybody selling it (reasonably) within driving distance. I did like Highland Clay when I could get it. It does look like I will have to get my porcelain from Bailey. Not sure about stoneware. Edited August 14 by Pyewackette Quote Link to comment Share on other sites More sharing options...
neilestrick Posted August 14 Report Share Posted August 14 22 minutes ago, Pyewackette said: OH! I see what I did there! I meant per 50lb box, not 25lb bag! Sorry! STILL SPENDY though. There it is! That makes more sense. Buying bulk is definitely the way to go. If you don't need that much yourself, see if a clay buddy can go in on it with you. Even at $77/box, that's less than $3 in clay to make a mug. It's expensive when you have to pay for all that clay, but when you break it down it's not too bad, especially if you can sell a few to pay for the hobby. Still cheaper than owning a horse or going on a ski trip! Pyewackette 1 Quote Link to comment Share on other sites More sharing options...
Pyewackette Posted August 14 Report Share Posted August 14 1 minute ago, neilestrick said: There it is! That makes more sense. Buying bulk is definitely the way to go. If you don't need that much yourself, see if a clay buddy can go in on it with you. Even at $77/box, that's less than $3 in clay to make a mug. It's expensive when you have to pay for all that clay, but when you break it down it's not too bad, especially if you can sell a few to pay for the hobby. Still cheaper than owning a horse or going on a ski trip! Oh but I have done both, and thoroughly enjoyed it. I'm a bit old for such shenanigans these days. Besides, I can't get my son and DIL to agree to a couple/three backyard chickens, let alone a horse. Thing is I've become accustomed to paying $28 for a box of cone 6-10 porcelain, speckled buff (with iron not manganese) or Balcones dark. It'sa gonna hurt to have to start paying retail. Quote Link to comment Share on other sites More sharing options...
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