Light Dimmer powering blower/squirrel cage?

[K1JJ]

Does anyone have experience using a standard 120VAC light dimmer to power a blower/squirrel cage fan?  I wonder about start-up load stress and longevity.  I'm looking at 150-200 CFM size blowers - not all that big.

I use Variacs now for the rigs, but want to add a few blowers around the house to circulate warm air from the coal stove and use the cheaper, easy-to-install dimmers to ramp down the fans at times.

Anyone doing this now?

T

[W7SOE]

Coal stove!!??

[KD3CN]

My fireplace insert has two good-sized Dayton blowers in it, and came with a plug-in rheostat for fan speed control.  It worked well, but wasn't heavy duty enough - only lasted a few winters.

73, Karl

[WA1GFZ]

Inductive loads can be an issue with dimmers.
Do they make speed controls for over head fans?

[K1JJ]

Yeah, even a switch-type speed control would be acceptable.   If no one knows for sure, I'll do some more searching.


Just picking up a used 5-year-old Harman Mark III coal stove for a good price, good for 95,000 BTU, 550 pounds! That thing will drive me outa the living room, so gonna add ducting to push warm air into the radio room and kitchen/downstairs bedroom using the blowers. (Remember that I suck in outside for the rigs - cold)  I put the blowers right at the top of the wall/ceiling junction to access the warmest air. The cold air will circulate back along the floor. Evidently a whole house can be covered with a few well placed fans.  The upstairs naturally gets warmed via the stairway hallway, as I've found with the existing wood stove.  I'm just tired of hauling wood and restarting the fire. This coal stove should stay on for months....

T

Here's a pic of the stove and one in action:

[ke7trp]

The Dimmers are not going to work well for the motor.

Check out Ebay item  180495994633

They are $19 and work exactly like need.  You just cant use Brushless motors. Only normal Brush type.

The other option is the $7 units on ebay. They are 2.5 amp so confirm thats large enough and you will need to panel mount them and wire them up.  Just search AC motor control on ebay

I have used Variacs on Brushless motors before. It seems to never work out.  The motors run real, real hot if you try to go to low. Full blast, The motor and shaft runs cool.

I used Dayton blower in my 4-400 rig.  Its very smooth. I made a rubber gasket for it so its isolated from the chassis.  

[K1JJ]

Thanks Clark - I'm going to order two.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180495994633&ru=http%3A%2F%2Fshop.ebay.com%3A80%2F%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D180495994633%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1


The ad says:
"Will not work on induction, shaded pole, soft/slow start, or brushless type motors."

Hmmm...  I am using a common 120VAC 5" muffin fan and an unmarked  squirrel cage 120VAC blower. Not being an electric motor kinda guy, how do I know if either falls under this restricted category?

T

[ke7trp]

I doubt the muffin fan will start.  This is why They are suggesting you cant use the control on this type of fan.  Brushless motors have a low tolerance for low voltage.  What I did was to use a bypass Relay with a timer control on it. The fans come on full blast, then after 90 seconds, They go to low.  With this arrangement, i dont see why it wont work, OR, Just turn the controll all the way up to start the fans.

C

[flintstone mop]

Soooo parts of your house will sound like a microwave oven cooking, Tom?

I might be making a bad decision for our house. We plan to heat with GAS. Supposedly excessive gas in storage from the Marcellus Shale....................And Rendell wants to tax the gas industry for that..............prices are down to $5.30 /mcf.

Coal is kewl.
Fred

[WQ9E]

A couple of years ago I had one of the pedestal fans in my Desk KW go up in smoke (literally).  I replaced them with a couple of larger Rotron "patriot" fans but I didn't want to run them at full speed since they produced much more air flow than the originals (or what was needed).  I bought one of the units designed for motor speed control but I still ran into problems with the fans wanting to change speed as they/the controller warmed up and the controller was creating some electrical noise.  I was lucky in my case to be able to put the two fans in series (running from 120V) and the speed is perfect at this level with very little noise.

There was an article in Electric Radio that dealt with using a motor speed controller for the blower in the Heathkit KL-1 "Chippewa" and it would be worthwhile to refer to that article for additional information.  It appeared in February and March of '98 but I am away from my ER collection right now so I don't know which installation of the article covered blower speed.

[WA1GFZ]

Tom,
Phelps and Sons on Rt 30 Vernon by the intersection of RT31 is by far the best place to buy coal.
There is a lot of junk coal out there that will drive you crazy. When you drop junk coal on a hard surface it has a thud sound. good hard coal has more of a ring. I burned two tons a year for many years. I had the stove in the basement that kept it in the 80s with the rest of the house in the 70s. It is very nice even heat but a bit dusty. I only had to load/shake the stove twice a day. The basement stove kept the floors nice and warm.

[KB2WIG]

I've got a Gayuta Andes cylinder stove. I can't find much on the google.  any stove guru?    गुरु

..... I know coal stoves can burn wood, how can ya tell if you have a coal stove, a wood stove or a stove that can burn both?   Coal burns hotter and ya cant just burn it in anything. 


klc

[W7SOE]

I had no idea people were still burning coal, I guess I am a left coastie....

My previous house had a coal chute, last used in the twenties.  Some of the houses here in Portland still have (non-used) wood burning furnaces.

Rich

[K1JJ]

OK Clark - I can live with starting the motor on fast. I'll order those controllers. Thanks again for the info.




"I know coal stoves can burn wood, how can ya tell if you have a coal stove, a wood stove or a stove that can burn both? "

From what I know, a stove designed for coal will have a movable "grate" at the bottom to shake the ashes into the pan below to shake down. A wood stove usually needs no movable grate and will be stationary. The ashes just fall to the pan for wood. Coal produces about 8-10 times more ashes than wood, so needs to be cleaned out more often - but the coal stove will stay lite longer, like 18-24 hours on the bigger ones.

There are combo wood/coal stoves too.  I think it may be best to get one optimized for wood OR coal however.

A coal stove burns much hotter than a wood stove, so there is more stress on the firebox components, esp the grate. Easy to warp or break it with heat.  

Some coal stoves can be used for wood with slight mods. One mod is to add a steel plate to cover the grate somewhat. The info is on the web for any particular stove. There are laws against switching fuels around like that, however.

Frank - the guy included 1.5 tons of coal with the stove, so I'll be schleping this weekend with my truck...

T

[KL7OF]

Coal stoves are made from cast iron.....Wood stoves can be made from steel...coal will melt steel...

[KB2WIG]

From what I know, a stove designed for coal will have a movable "grate" at the bottom to shake the ashes into the pan below to shake down. A wood stove usually needs no movable grate and will be stationary.

That’s what my old man said. The stove has the revolving grates. The OM usda stoke the low pressure babies.  But he said, you better have someone look at it.

 The info is on the web for any particular stove.

Not for this baby


There are laws against switching fuels around like that, however.

So far, not in the hills of NY……. Or so I think 



The nice thing about wood, other than the woodsy sound, is that the ash is gud fer the soil. Coal ‘ash’ is good if you want to use it for a filler or as part of a road base….  Snot good to have lying around….

I use a fan to blow the heat around the cellar. I pulled out the 2KW lectric heater. Way to much juice....  Maybee I'll get the 813X813 rig going; i've not done anything with her fer 3 years.  (need a name fer her)

klc

[KB2WIG]

.

[WA1GFZ]

If you burn quality coal you can run at about 200 degrees stack temperature and have plenty of heat.
I dumped my ash pan once or twice a week because good coal isn't full of sand. It will be fairly light colored. Dark gray means lots of dirt. Quality coal stays burning. I could go all season and maybe have it go out once or twice. Usually it was my fault being too lazy to get up early on a weekend or away from the house at feeding time.
The hardest thing to learn is how to feed the coal without filling the house full of dust. The best method if you have the time is throw a shovel of coal in and let it get going good so there is plenty of draft. Then shake it down.
Wood was a big pita.
If you get into it build a bin under a basement window then Phelps can deliver it and shoot it right into the bin. I hauled many a pickup load. 2 tons was usually 3 trips.

[K1JJ]

Not for this baby

Nice old buzzard stove!  I'll bet that's a 90K BTU from the looks. It's almost looks bronze?

Steve, I could be wrong, but the Harman body is made from a single piece of 1/4" steel and robotically welded. The door is cast since there is no firebrick in front. I realize 2000 degrees (coal burning temp) will melt steel, but I think the body is insulated by the firebrick. The temp gauge on top varies from 200-600 degrees F according to the specs. The grate is cast iron since it is in contact with the coal, however. 

Frank, interesting about the coal quality. I thought I'd be getting away from that with the wood problems, but guess coal varies too. I didn't even look the coal over I'm getting from the guy.

The bin idea is appealing. I wonder if one could be built outside? Why does everyone put it in the cellar? Not sure if the bin has to be below ground for gravity unloading - or maybe the weather outside will keep it too moist?

T

[vk3he]

Hi

This one works with shaded pole motors.

http://cgi.ebay.com/SmartFan-Nimbus-AC-Motor-Fan-Speed-Control-240vjw03-/180568826048?pt=LH_DefaultDomain_0&hash=item2a0abda0c0


73
Craig

Thanks Clark - I'm going to order two.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=180495994633&ru=http%3A%2F%2Fshop.ebay.com%3A80%2F%3F_from%3DR40%26_trksid%3Dp5197.m570.l1313%26_nkw%3D180495994633%26_sacat%3DSee-All-Categories%26_fvi%3D1&_rdc=1


The ad says:
"Will not work on induction, shaded pole, soft/slow start, or brushless type motors."

Hmmm...  I am using a common 120VAC 5" muffin fan and an unmarked  squirrel cage 120VAC blower. Not being an electric motor kinda guy, how do I know if either falls under this restricted category?

T

[WA1GFZ]

Phelps coal truck has an outlet at about 5 feet so the bin needs to be below that. There is no problem keeping it outside or in the garage. I filled my bulk head hole with a dam in front of the door. Inside the stove was about 10 feet away so I just opened the basement door and shoveled it out from below the bottom step. You don't want to move it too many times if possible.
Once you get the coal going you can idle it way back and get plenty of heat. I suggest you get a CO detector if the house is tight and you use it in the living area. I stunk the house out a couple times form having the house so tight that the stove got choked out. First your head hurts from lack of O2.
My father in Law used to get coal delivered. He could do bags or loose.
Bags are easier but the cost is higher.  I liked the big stove coal the best but medium nut coal was also ok. That depends on your grate. Run the coal too hot and the cast grate will sag in time. I replaced mine once. It is good to have a spare one around. My grate failed in the middle of the winter and it took a week to get anew one.

[K1JJ]

Good info, Frank, Tnx.

Yes, the bags are easy to work with, though the initial loading and unloading makes the bin easier.  I'm thinking of what material I cud make the bin with. Pressure treated lumber or maybe there is a clever way to build a cheap concrete bin outside.  

I installed my two strategically placed blowers tonight. I have them both sucking warm air within a few inches of the ceiling and blowing it into the next rooms thru the walls. The shack now has a good breeze from the stove room. It was always cold in there cuz that room has a crawl space below. We'll see.

OK on the grate sag. I checked prices and they want $400 for the three grates this Harman requires. Hope the exisiting one lasts for a long time. The stove is so big compared to the old stove and is overkill for the room. I'm hoping to run in low most of the time.

Later -

T

[WA1GFZ]

Tom,
Check for air valves so you can idle it back. 25K to 30 KBTU should keep that place warm. You might consider going under the shack and adding insulation with foam over the bottom of the floor Joists. Go easy on the grate when you fire up the stove without ash on top of it. Mine is almost an inch thick and it still sagged. 4X4 posts lag bolted to 2X10s would make a nice bin with pressure treated.

[K1JJ]

OK, Frank - good info, tnx.

I did add fiberglass insulation years ago, but still is cold. I understand they cud blow in foam, but I wudn't be able to access the crawl space anymore for whatever, right?

Interesting on making an outside coal bin using 4X4 posts and 2X10 sides.   I might do that next year. I picked up 2/3's of the bagged coal today and think I'm set for the year. Got the stove and it's sitting in the garage here now. Want to build a brick pedestal for it. Have to do some reading on the web so I don't so a Three Stooges job.

I looked at the grate closely today and see an ever so slight sag in it. There's three in there and they cost $400 new total, so I'm gonna nurse these. Gonna add new door and glass gaskets and repaint it with high temp flat black. The paint is rated at 1200 degrees - I hope that's high enuff for the outside of a coal stove.  I'm taking the old wood stove to the metal yard as scrap. Maybe I can trade them for some aluminum sheet.


T

[WA1GFZ]

Tom you need to seal the cavity. We had the same problem at my Dad's place when we built a family room off the back of the house. We had to put plywood across the bottoms of the floor joists  to make the insulation effective. I would use 1 or 1 1/2 inch polyisocyanurate attached to the bottoms of the floor joists. It goes for about $14 for a 4X8 sheet at home chepo. I used it under all the sheetrock in the new place with an air gap between. Steve did the same thing at his place. I also used aluminum duct tape on the seams. I attached it with 3 inch deck screws with the aluminum discs you use to hold down tar paper. about .01 inch thick washer to help holding the foam up.. They are cheap and come in a nail sized box. The foam is light and easy to work with. 1 inch is R6.5 and 1 1/2 is R10.
Your grate runs the hottest when the coal first gets going since there is no ash between the fire and grate.