Central Boiler FORGE 3500 Outdoor Coal Boiler
- Lightning
- Site Moderator
- Posts: 14658
- Joined: Wed. Nov. 16, 2011 9:51 am
- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
We counted roughly 90 feet total of baseboard in the house. I got some conflicting numbers on the IR gun, though it seems to be around a 21-22 delta between the supply and return. The pex at the boiler appears to at least 1 inch. Some of the radiator lines I saw were 3/4. I believe there to be a lot of friction head since many of the radiator runs come down from the ceiling and then back up and over to the next room. There isn't very much exposed lines in the attic, maybe a few feet.
Most of the print on the circulator was illegible. Here's a pic of it. After blowing up the pic, I guess you can read it.
I'm thinking he needs a bigger pump along with more radiation.
What's your thoughts?
Most of the print on the circulator was illegible. Here's a pic of it. After blowing up the pic, I guess you can read it.
I'm thinking he needs a bigger pump along with more radiation.
What's your thoughts?
Attachments
- lsayre
- Member
- Posts: 21781
- Joined: Wed. Nov. 23, 2005 9:17 pm
- Location: Ohio
- Stoker Coal Boiler: AHS S130 Coal Gun
- Coal Size/Type: Lehigh Anthracite Pea
- Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
It looks like a Grundfos 15-58 Three-Speed. On high speed it will deliver 7 GPM in the presence of 12 ft. of friction head. A well respected circulator.
Downs and ups are irrelevant. No head contribution from that. What matters is the ID of the 1" PEX (which will be 0.863" if it is standard PEX, and not PEX-AL-PEX) and the total run length for the single zone loop.
Downs and ups are irrelevant. No head contribution from that. What matters is the ID of the 1" PEX (which will be 0.863" if it is standard PEX, and not PEX-AL-PEX) and the total run length for the single zone loop.
-
- Member
- Posts: 558
- Joined: Thu. Sep. 04, 2014 10:01 am
- Location: Western NY 14141
- Stoker Coal Boiler: Keystoker KB-8
- Coal Size/Type: Buckwheat
- Other Heating: Utica Propane Hot Water
2500sq ft x30 btu needed per sq ft=75000 btu required
500 btu per ft x 90 ft of baseboard means 45000 btu going in in a perfect world.
Not to mention 3/4 can only carry so much before it cools down towards the end of the loop.
Time for a second loop with lots more base board
500 btu per ft x 90 ft of baseboard means 45000 btu going in in a perfect world.
Not to mention 3/4 can only carry so much before it cools down towards the end of the loop.
Time for a second loop with lots more base board
Last edited by Olllotj on Wed. Dec. 05, 2018 8:06 pm, edited 1 time in total.
-
- Member
- Posts: 6515
- Joined: Sun. Feb. 10, 2008 3:48 pm
- Location: Cape Cod, MA
- Stoker Coal Boiler: want AA130
- Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
- Coal Size/Type: Pea/Nut/Stove
Nice thing is you can zone up some rooms with the up to the ceiling pattern...
- lsayre
- Member
- Posts: 21781
- Joined: Wed. Nov. 23, 2005 9:17 pm
- Location: Ohio
- Stoker Coal Boiler: AHS S130 Coal Gun
- Coal Size/Type: Lehigh Anthracite Pea
- Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
If we guess at an average of 500 BTUH per foot of radiators, and use your figure of 22 degrees of Delta-T, we get:
(500 BTUH/ft. x 90 ft.) = (22 x 8.34 x 60) x GPM
GPM = ~4
Looking at the 3 available pump curve(s), his friction head "ballpark" for a "ballpark" of 4 GPM flow is as follows (multiple choice):
1) For the case whereby he is running the circulator on low speed, friction head = ~6.5 ft.
2) For the case whereby he is running the circulator on medium speed, friction head = ~12.2 ft.
3) For the case whereby he is running the circulator on high speed, friction head = ~15.4 ft.
(500 BTUH/ft. x 90 ft.) = (22 x 8.34 x 60) x GPM
GPM = ~4
Looking at the 3 available pump curve(s), his friction head "ballpark" for a "ballpark" of 4 GPM flow is as follows (multiple choice):
1) For the case whereby he is running the circulator on low speed, friction head = ~6.5 ft.
2) For the case whereby he is running the circulator on medium speed, friction head = ~12.2 ft.
3) For the case whereby he is running the circulator on high speed, friction head = ~15.4 ft.
Last edited by lsayre on Wed. Dec. 05, 2018 8:16 pm, edited 1 time in total.
- Lightning
- Site Moderator
- Posts: 14658
- Joined: Wed. Nov. 16, 2011 9:51 am
- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
Suppose the total length is 200 ft because of all the ups and downs and distance to and from the outside boiler which includes the 90 ft of baseboard. What kind of friction are we looking at? And based on that, how many BTUs are actually being delivered?
He told me the pump is on its highest setting.
He told me the pump is on its highest setting.
- lsayre
- Member
- Posts: 21781
- Joined: Wed. Nov. 23, 2005 9:17 pm
- Location: Ohio
- Stoker Coal Boiler: AHS S130 Coal Gun
- Coal Size/Type: Lehigh Anthracite Pea
- Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
At best flow is 5 GPM, and at worst perhaps 4 GPM. At 22 degrees of Delta-T and 5 GPM, the system is capable of putting 55,000 BTUH into the home. At 4 GPM the system is capable of putting 44,000 BTUH into the home. Best guess is therefore ~50,000 BTUH.
If he actually needs 70,000 BTUH he needs a higher output circulator. And even the Taco VT2218 I mentioned earlier will not be sufficient for the task.
If he actually needs 70,000 BTUH he needs a higher output circulator. And even the Taco VT2218 I mentioned earlier will not be sufficient for the task.
- Lightning
- Site Moderator
- Posts: 14658
- Joined: Wed. Nov. 16, 2011 9:51 am
- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
What's the ballpark decent price on baseboard radiators? He priced some at Home Depot around $85 for an 8 foot section, I believe. Is that the goin rate?
- Lightning
- Site Moderator
- Posts: 14658
- Joined: Wed. Nov. 16, 2011 9:51 am
- Location: Olean, NY
- Stoker Coal Boiler: Modified AA 130
- Coal Size/Type: Pea Size - Anthracite
I like that pump you suggested, I might have to have a couple lol.
His house is block with no insulation in the walls. Ceiling is well insulated. So he probably requires the high side, BTU wise. There are a couple rooms with a lot of glass too.
- lsayre
- Member
- Posts: 21781
- Joined: Wed. Nov. 23, 2005 9:17 pm
- Location: Ohio
- Stoker Coal Boiler: AHS S130 Coal Gun
- Coal Size/Type: Lehigh Anthracite Pea
- Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
Friction is a combined function of the system and the circulator. They are tied at the hip. Change the circulator brand/model and you change the friction head.
For the Grundfos 15-58 I believe he is within the ballpark of 4 to 5 GPM flow. Call it 4.5 GPM. The lower figure is highly predicated upon a reliable measure of an observed 22 degree Delta-T and a presumed 500 BTUH per foot of radiators. If the Delta-T is not 22 degrees and the radiators are not a nominal 500 BTUH the nominal 4 GPM guess is off also. The higher figure of "not more than 5 GPM" is a stab taken via the use of my spreadsheet and applying your total run length of 200 feet and guessing at a nominal pipe ID.
Last edited by lsayre on Wed. Dec. 05, 2018 9:03 pm, edited 2 times in total.
- lsayre
- Member
- Posts: 21781
- Joined: Wed. Nov. 23, 2005 9:17 pm
- Location: Ohio
- Stoker Coal Boiler: AHS S130 Coal Gun
- Coal Size/Type: Lehigh Anthracite Pea
- Other Heating: Resistance Boiler (13.5 KW), ComfortMax 75
I'm speculating (as in guessing) here, and consulting an HVAC professional would clearly be wise, but if you can find a circulator capable of delivering at least 7.5 GPM of flow at 15.5 ft of head, his house should be a lot warmer for it on the coldest few days of the year. One concern here is whether or not velocity noise becomes problematic in 3/4" copper pipe for the case of 7-8 GPM flow.
Last edited by lsayre on Wed. Dec. 05, 2018 9:14 pm, edited 1 time in total.