Airwash on Quad Castile move from Top to bottom
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There are several Quad wizards on this forum who have forgotten more than I'll ever know about these stoves, who I'm sure will chime in fish__. But as far as I know, given the asymmetrical design of the Quad door, there isn't any way to move the air wash from the top of the door to the bottom in the older style Castile, short of buying a whole new door and glass assembly. I believe the new door and glass would retrofit to the older style stove frame, but in the Quad tradition of excellent quality but pricey parts replacement costs, that would be big $$$$. If you did replace the door you would probably also want to upgrade your fire pot, if you still have the older style ceramic one, to the new style that is cast steel, and that had the air hole placements tweeked for more efficient fire pot air flow. My original ceramic fire pot cracked, so I replaced it, and the newer style does seem to have better air flow design.
An advantage I've found of having the air wash on the top is the easy modification you can do to get more heat out of the stove, by partially or completely covering the air wash gap so more air is pulled through the fire pot, which results in a lower flame but a more concentrated and hotter fire pot burn. I compare it to starting a campfire by blowing through pursed lips vs just allowing the ambient breeze to 'fan' it. Though it does help aesthetically to keep the glass clean, the air wash, especially when on the top, is in essence 'ambient' breeze' air moving through the stove and not really contributing to the fuel combustion process.
To block the air wash I just take a couple of foot long length of the fattest diameter fiberglass wood stove gasket rope and lay it over the air wash opening up tight against the stove frame, which shuts down most of the airflow through the air wash, but not all of it, so the glass stays cleaner a little longer than if it was completely blocked, while still boosting your stoves heat output. When it's below zero or blowing like stink out I cover the entire air wash completely with heavy duty aluminum foil folded and crimped to completely shut off the air wash flow to give the max air flow through the fire pot. I've heard some folks use the aluminum foil system and just cover part of the air wash opening to help keep the glass cleaner but still get more btu output. So it is an easy modification to 'modify', as it were. You can then tweek with the pellet feed gate inside the hopper to find the optimum burn efficiency for the particular brand of pellet you're burning.
I definitely have to clean the glass more regularly than if the air wash was left unobstructed, but burning platinum quality softwood pellets significantly helps in reducing the amount of overall ash production, which together with these mods helps coax the max amount of btu's out of the stove as possible. With my venting configuration, I'm at the top end of the recommended EVL of 15, so if I don't block the air wash I get poor stove airflow and thus an inefficient burn on the low heat setting that I use in the shoulder season times of the year like this, when I don't need the max heat output and instead want the stove to not cycle on and off as much, which helps keep a more steady room heat.
Doing this air wash modification, together with wiring the convection fan to run on high regardless of the stove's heat setting, resulted in me burning a 1/2 ton of pellets less last year than the year before, (same brand of pellets, keeping the thermostat at the same temp setting if not a little warmer). This was despite a harsh NE winter where most folks burned a ton or more pellets beyond what they typically burn in a normal winter.
Search under "Quad modifications" and you will find several of tj and B-mods most excellent posts on how to do these and a few other Quad mods as well. They work great and were simple and inexpensive to do, even for the electrically and mechanically challenged like me !!
An advantage I've found of having the air wash on the top is the easy modification you can do to get more heat out of the stove, by partially or completely covering the air wash gap so more air is pulled through the fire pot, which results in a lower flame but a more concentrated and hotter fire pot burn. I compare it to starting a campfire by blowing through pursed lips vs just allowing the ambient breeze to 'fan' it. Though it does help aesthetically to keep the glass clean, the air wash, especially when on the top, is in essence 'ambient' breeze' air moving through the stove and not really contributing to the fuel combustion process.
To block the air wash I just take a couple of foot long length of the fattest diameter fiberglass wood stove gasket rope and lay it over the air wash opening up tight against the stove frame, which shuts down most of the airflow through the air wash, but not all of it, so the glass stays cleaner a little longer than if it was completely blocked, while still boosting your stoves heat output. When it's below zero or blowing like stink out I cover the entire air wash completely with heavy duty aluminum foil folded and crimped to completely shut off the air wash flow to give the max air flow through the fire pot. I've heard some folks use the aluminum foil system and just cover part of the air wash opening to help keep the glass cleaner but still get more btu output. So it is an easy modification to 'modify', as it were. You can then tweek with the pellet feed gate inside the hopper to find the optimum burn efficiency for the particular brand of pellet you're burning.
I definitely have to clean the glass more regularly than if the air wash was left unobstructed, but burning platinum quality softwood pellets significantly helps in reducing the amount of overall ash production, which together with these mods helps coax the max amount of btu's out of the stove as possible. With my venting configuration, I'm at the top end of the recommended EVL of 15, so if I don't block the air wash I get poor stove airflow and thus an inefficient burn on the low heat setting that I use in the shoulder season times of the year like this, when I don't need the max heat output and instead want the stove to not cycle on and off as much, which helps keep a more steady room heat.
Doing this air wash modification, together with wiring the convection fan to run on high regardless of the stove's heat setting, resulted in me burning a 1/2 ton of pellets less last year than the year before, (same brand of pellets, keeping the thermostat at the same temp setting if not a little warmer). This was despite a harsh NE winter where most folks burned a ton or more pellets beyond what they typically burn in a normal winter.
Search under "Quad modifications" and you will find several of tj and B-mods most excellent posts on how to do these and a few other Quad mods as well. They work great and were simple and inexpensive to do, even for the electrically and mechanically challenged like me !!
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I guess you could just install the new gasket with the full tadpole on top, and the cut "tail" on bottom. Just make sure the gasket wraps around the bottom edge of the glass so it doesn't contact the metal. Why do you want to change it?
I saved two small sections of old tadpole gasket for the same purpose. The thin part slides into the airwash. I don't block the entire length of the airwash... embers would get blown out of the burnpot, leaving small charred pieces (incomplete combustion) in the firebox.
Here's a couple:
https://www.hearth.com/talk/threads/quadrafire-castile-experiment.58216/
and
https://www.hearth.com/talk/threads/my-quadrafire-1200-re-anaysis.75329/
Good info Swine Flue - my Castile does throw embers more with the air wash blocked, mostly when the pellets drop, but the stove gasket rope I block it with definitely isn't as air tight as the tadpole gasket material is. My firebox does have some larger sized pellet char, so I'm going to experiment with less air wash obstruction. When you say you saved two sections of old tadpole gasket, I assume you cover the edges of the air wash and leave the middle open?
Yup, sometimes I use only one of them. This time of year, I don't bother at all. Come to think of it, maybe I should... it might reduce the soot from running GS pellets on Low with the feed gate closed.
DMKNLD holy crap that is one of the best replies I have ever seen on a forum I am so impressed. I read a lot about what Bmod and Tj had done to the castile. I think it was a post by bmod that said he had moved his airwash from top to bottom. The top airwash seems like it just will pull hot air back into the stove. I have added the springs, an adjustable snap disk, installed a new convection blower that was rated for a 180 CFM and installed a switch so I can run on high all the time or reduced speed when I want quieter operation. Doing these changes I saw about a 10 C drop in exhaust temperature. I have a thermal couple installed right at the exit from the stove. I played around with blocking of the airwash but I did not see a large drop in exhaust temp. But I may not have run the test long enough and I had a mix of pellets that may have skewed the results. So will try some more once it gets a bit cooler outside.
Thanks for your kind thoughts, Fish. Before I found this most excellent forum I was completely clueless on pellet stove operation and maintenance. Luckily, there are many Quad folks (and others) on here with the MRA (mechanical reasoning ability) that I clearly lack. My MRA is somewhere between zero and the null set, so I owe my ability to now at least rudimentarily trouble shoot and maintain my stove to B-mod, Tj, Kap, Swine flue, among others. It will be great to include you on that list as well.
You're definitely doing more definitive evidence based research than I am with your thermocouple testing. Mine is just anecdotal and experiential, where I know besides less pellet use and more even heat distribution through out our farmhouse despite last years extreme winter, that these mods do indeed work. I remember my first season burning pellets, on medium setting my convection fan would constantly cycle on and off with the stove box temp fluctuations, and on most mornings the dino burner would kick on in the early AM hours when the Quad couldn't keep up. We were lucky if the house stayed above 65 F or so. But I was also burning the first generation MWP blend pellets, which un-affectionately came to be known on this forum as 'dirt in a bag'. MWP made allot of improvements their 2nd season in production quality, so that undoubtedly helped my stove efficiency my 2nd year of pellet burning.
After doing all the above mods you mentioned, together with burning platinum grade 100% softies, the convection fan hums along now non-stop on medium setting and the oil furnace very rarely kicks on, even if I get behind on my usual OCD cleaning schedule. I only need to run the Quad on high setting when it is well below zero and windy in order to keep the house in the low 70 F room temps, so I feel like I'm squeezing about as much BTU per bag of pellets as I can out of my Castile. As always, improved insulation R-values and air infiltration control will be an on-going project in our circa 1870's Maine farmhouse.
Keep us posted on how the air wash obstruction testing effects your exhaust temp readings. Cheers!
You're definitely doing more definitive evidence based research than I am with your thermocouple testing. Mine is just anecdotal and experiential, where I know besides less pellet use and more even heat distribution through out our farmhouse despite last years extreme winter, that these mods do indeed work. I remember my first season burning pellets, on medium setting my convection fan would constantly cycle on and off with the stove box temp fluctuations, and on most mornings the dino burner would kick on in the early AM hours when the Quad couldn't keep up. We were lucky if the house stayed above 65 F or so. But I was also burning the first generation MWP blend pellets, which un-affectionately came to be known on this forum as 'dirt in a bag'. MWP made allot of improvements their 2nd season in production quality, so that undoubtedly helped my stove efficiency my 2nd year of pellet burning.
After doing all the above mods you mentioned, together with burning platinum grade 100% softies, the convection fan hums along now non-stop on medium setting and the oil furnace very rarely kicks on, even if I get behind on my usual OCD cleaning schedule. I only need to run the Quad on high setting when it is well below zero and windy in order to keep the house in the low 70 F room temps, so I feel like I'm squeezing about as much BTU per bag of pellets as I can out of my Castile. As always, improved insulation R-values and air infiltration control will be an on-going project in our circa 1870's Maine farmhouse.
Keep us posted on how the air wash obstruction testing effects your exhaust temp readings. Cheers!
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I wouldn't be at all surprised if you saw the exhaust temperature increase. By blocking the airwash, less air is going through the stove... at the same temperature less air will take less heat out the exhaust. You'll have to measure convection temps to see the benefit.
Harvey Schneider
Minister of Fire
It's probably the same amount of air, or close to it. The air is going through the burn pot instead of around it. The fire should be burning hotter and the effluent isn't being diluted with cooler air, so one might expect a rise in flue temperature instead of a drop.
I don't think this mod is an efficiency mod, I think it may cause a slight increase in heat output. The reason I say this is that the additional fire pot air flow is going to burn pellets faster/hotter. That will result in more BTU's being consumed per time. Efficiency change is harder to see, but I don't think it will be significant unless the original burn was oxygen deprived.
Just my thoughts, no proof that I'm right.
In the very short term, yes. But available BTUs are limited by the simple fixed feed rate of the "Control Box" Quads (all models except the AE and E2).
The only way to increase BTUs long term is either higher efficiency or a higher feed rate, and we're not changing the feed rate. A faster burn would just cause the flames to die down a bit sooner between pellet drops.
Blocking an opening will reduce airflow to some degree. The amount of air may be close to the same, I don't know... measuring airflow is beyond our capability (mine anyway). These simple stoves have fixed feed and blower rates, so we can gauge combustion performance by measuring convection temperatures. (Similarly, tjnamtiw IMO proved his heat exchanger tube mod when he measured an EGT reduction.)
I did see an improvement when I first tried this a couple of seasons ago:
I just tried inserting and removing foil (several times) to block the middle ~50% of the airwash. Using an IR gun, the convection tube temperatures are a consistent 50-100hotter with the foil
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