Harman Magnum Stoker - Hot Water Coil Hookup for Hot Water?

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 8:25 am

that makes perfect sense.

Man, I def do not have any out of the box thinking when it comes to this stuff!:idea:

Thanks!!!!


 
User avatar
coaledsweat
Site Moderator
Posts: 13761
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Tue. Oct. 16, 2007 9:42 am

Be sure you size the fitting it is going in is large enough, don't put a 1/2" well in a 1/2 or 3/4" pipe. Go big around the well. The ebay picture shows the aquastats, it does not appear that there are any wells with them. The probe slips into the well which has to be screwed into whatever pipe you have chosen to install. The well seperates the probe from the liquid so you can service the probe without losing water from the system. I would see if the unit comes with a well, as you need one with it.

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 10:42 am

coaledsweat,

Thanks, this unit does not come with a well. I will need to get one. Will home depot have something like that?

Bare with me, I'm a little slow.

What do you mean "go big around the well"?

Do you mean that for my 3/4" system that I need a well fitting bigger than 3/4"?

I was going to do what matthaus suggested and put a 3/4" T near the output from the stoker and put a well in the 'T'.

 
User avatar
LsFarm
Member
Posts: 7383
Joined: Sun. Nov. 20, 2005 8:02 pm
Location: Michigan
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Post by LsFarm » Tue. Oct. 16, 2007 10:52 am

The probe for the well will act like a finger sticking into the fitting or pipe. Provide a lot a room around the probe by using [for example] a 1" fitting instead of 3/4" so that the probe of the well will not restrict the water flow.

Once you get the well and try it into a few fittings you will see how restrictive it could be in a fitting that is 'just big enough'.

Greg L

 
User avatar
Yanche
Member
Posts: 3026
Joined: Fri. Dec. 23, 2005 12:45 pm
Location: Sykesville, Maryland
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

Post by Yanche » Tue. Oct. 16, 2007 11:06 am

Some photos of installed plumbing temperature wells. These are in 1-1/2 copper supply lines with appropriate reducing fittings to accommodate the well thread size. The one in the straight run "tee" was intended to sense the water temperature of my underground supply line as it enters my home. The idea was to have a independent control if the temperature in the underground lines got close to freezing. I would then turn on the pump and circulate some water. Never needed because I buried and insulated my supply and returns lines so well they never get close to freezing even with no flow. The 90 degree turn "well" is atop my oil fired boiler. The idea was to sense boiler water temperature independent of the boiler's aquastat so I could default to the oil boiler as a backup if the coal boiler failed. Not yet implemented because with my single flue chimney it's an either or operation. Coal in winter, oil in summer. Note in each the length of the well stub is cut so that the sensing end of the bulb will be in the water flow. The third photo is a typical Honeywell sensor switch that's inside a aquastat. Separate high, low and differential (hysteresis) set knobs. The copper bulb next to the measuring scale is what goes into the "measuring well", the apparent opening at the top. It's not really open, just a cavity to accept the sensing bulb. Well's are available in 3/4 or 1/2 male thread sizes. Both have the same internal diameter for the sensing bulb.

Attachments

Aquastat_Temp_Switch.jpg
.JPG | 39.3KB | Aquastat_Temp_Switch.jpg
Temp_Well_in_Tee.jpg
.JPG | 36.6KB | Temp_Well_in_Tee.jpg
Temp_Well_in_El.jpg
.JPG | 33.3KB | Temp_Well_in_El.jpg
Last edited by Yanche on Tue. Oct. 16, 2007 11:14 am, edited 1 time in total.

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 11:06 am

ohhh, I get it.

So for example:

I may put a 1" T inline with my system with some 1"-3/4" reducers so the water will flow from the stove into a 1" T around the well finger and then back into the 3/4" pipe. This way the volume of water will not be restricted by a well finger sticking into the middle of the pipe!

Man, you guys are awesome! This project would have been a disaster without this forum!!!

Sat is the big day to tackle the majority of this project :)

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 11:12 am

thanks Yanche!

Ok, so another important point is to make sure that some portion of the well finger is in the flow path of the water.

hmmm.... Do you think 1" is big enough or would I need to go bigger based on your experience?

Thanks!

Jeremy


 
User avatar
coaledsweat
Site Moderator
Posts: 13761
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Tue. Oct. 16, 2007 11:18 am

1" should do it if the well is 1/2", if its 3/4, I would go 1 1/4".
The increase in flow is exponential to the pipes increased dia.

You should be able to get the well at a plumbing/heating supply house, Graingers may have them too.
Last edited by coaledsweat on Tue. Oct. 16, 2007 11:22 am, edited 2 times in total.

 
User avatar
Yanche
Member
Posts: 3026
Joined: Fri. Dec. 23, 2005 12:45 pm
Location: Sykesville, Maryland
Stoker Coal Boiler: Alternate Heating Systems S-130
Coal Size/Type: Anthracite Pea

Post by Yanche » Tue. Oct. 16, 2007 11:20 am

1 inch will be large enough. I've got 1-1/2 pipe sizes because I'm potentially moving the entire 130K BTU's of my boiler's output. You have much less capability in your heating coil.

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 11:27 am

just to clarify, when you say 3/4" well and 1/2" well. Are we talking depth of the well or the diameter of the fitting?

 
User avatar
coaledsweat
Site Moderator
Posts: 13761
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Tue. Oct. 16, 2007 12:10 pm

beatle78 wrote:just to clarify, when you say 3/4" well and 1/2" well. Are we talking depth of the well or the diameter of the fitting?


The NPT thread size of the well.

 
User avatar
beatle78
Member
Posts: 1026
Joined: Wed. Oct. 03, 2007 1:46 pm
Location: Rhode Island

Post by beatle78 » Tue. Oct. 16, 2007 12:56 pm

coaledsweat wrote:
beatle78 wrote:just to clarify, when you say 3/4" well and 1/2" well. Are we talking depth of the well or the diameter of the fitting?


The NPT thread size of the well.
Bare with me here. Why would the NPT size of the thread cause me to need a larger diameter pipe? 1" -> 1-1/4"

Is the 1\2" well also shallower than the 3/4" Well?

Also, can I use either a 1/2" or 3/4" well or is that determined by the size of the probe?

 
User avatar
coaledsweat
Site Moderator
Posts: 13761
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Tue. Oct. 16, 2007 3:01 pm

The well will stick into whatever you put it in about 4-5". If you have run 3/4" pipe and put a 1/2" well in it, it will cut your flow by about 75% of the original flow. It may work fine as is, I would go larger. It may be me, just anal retentive engineering that's all.
To visualize, take a quarter (3/4" pipe) and place a penny (1/2" pipe) on it. Now the only path your water has is the silver that shows, you won't be moving much water through it after the well goes in.

 
User avatar
coaledsweat
Site Moderator
Posts: 13761
Joined: Fri. Oct. 27, 2006 2:05 pm
Location: Guilford, Connecticut
Stoker Coal Boiler: Axeman Anderson 260M
Coal Size/Type: Pea

Post by coaledsweat » Tue. Oct. 16, 2007 3:05 pm

beatle78 wrote:Also, can I use either a 1/2" or 3/4" well or is that determined by the size of the probe?
The well size is determined by your probe, it must fit snug. Also you should get some kind of gook with the well, it helps the heat transfer. It isn't critical but it makes it more accurate and responds quicker as the heat transfer is optimized.

 
User avatar
LsFarm
Member
Posts: 7383
Joined: Sun. Nov. 20, 2005 8:02 pm
Location: Michigan
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Post by LsFarm » Tue. Oct. 16, 2007 3:28 pm

I think once you get a well in hand, and thread together a tee and a reducer/adapter for the well, you will see what coaledsweat is pointing out. As long as the well isn't choking off the flow, it should do fine, a little extra room for the water to flow may be better. Just don't restrict it to less than an unobstructed pipe.

I don't have any of the 'gook' :) for any of my aquastat probes and wells. Is there a high temp heat conductive product available,, could I just use some other product? I have taken many apart, and have never found the heat conductive grease or gook. Any ideas?

Greg L


Post Reply

Return to “Stoker Coal Furnaces & Stoves Using Anthracite (Hot Air)”