Dana, lots of information there, thank you very much.
My weekend warrior brain is in overdrive.
Yes, I meant the boiler, I have hydronic baseboard heat.
I had a look at the heat load calculator....might be a bit confusing for my brain, too many permutations that I am unsure of.
So then I went to the fuel based load calculation link - it's dead. Do you have any alternatives ?
The link works for me as of a few seconds ago- perhaps their server was under maintenance when you tried it?
Try again, this time spelled out:
https://www.greenbuildingadvisor.com/article/out-with-the-old-in-with-the-new
For what it's worth, I have about 80 linear feet of the larger type of slantfin (3/4 copper with 3" fins).
1250 sq ft, 8' ceilings throughout. One main floor with an insulated attic space. It was built in the 50's so I will "guess" that it's poorly insulated in order to get a worst case scenario to see if the current set up will support the additional basement load, which presumably is what this is all for. Windows are wood frame, single pane with very cheap storm windows, and look to be original or at least 30-40 years old.
At an AWT (average water temp) of 170F (180F out of the boiler, 160 return) 80' of
typical SlantFin baseboard emits about 42,000 BTU/hr. So if the place has been staying warm even during Polar Vortex disturbance cold snaps the design heat load at the 99% outside design temp is
well under 40,000 BTU/hr.
You might try an
IBR type load calculation using a spreadsheet to verify the heat load.
Typical 1950s wall insulation was R0 (=empty cavities) to R11, rarely R13. If it's been retrofitted with blown in fiberglass, rock wool, or cellulose figure on R13. The framing fractions of most 2x4 framing of the era is about 25%, meaning that 25% of the wall area has thermally bridging studs/headers/top & bottom plates, etc behind the sheathing, at about R 4.2, which has to be taken into account when calculating the "U-factor" (- BTU/hr per degree F temperature difference per square foot of wall, not counting windows & doors). So at a 60F temperature difference (a typical 99% design temp for CT of 10F outdoors, 70F indoors) the heat loss of above grade walls is
U-factor x 60F x area of framed wall= BTU/hr
With typical sheathing and siding options the
U-factor of an empty wall cavity at a 25% framing fraction is about 0.36BTU/hr per degree F temperature difference per square foot of wall (not counting windows & doors), an R11 runs about U0.11, a typical R13 wall runs about U0.10. For a quick & dirty pretty good rough-cut, U0.10 is usually pretty close.
The framing fractions of roofs and ceilings are typically much less, an there are are similar
tables for roofs & ceilings.
The wild card is the basement & foundation walls. A typical poured concrete wall with no interior or exterior cladding or insulation runs about U0.1 (includes air films) , a hollow core block wall about U0.7, but it varies a lot, and that's only for above-grade portions of the walls. Whatever it is, the heat loss of uninsulated foundation wall is still significant, and can be reduced by an order of magnitude bringing it up to current code minimums (R15 continuous insulation). There are real mold & rot risks to insulating the foundation with just a non structural batt insulated wall, but it's not hard to do it in such a way to keep it dry and mold free, summer & winter. I'll spare the details unless you're going that route.
Single pane wood sash with clear glass (not l0w-E) runs about U0.5, as do 2" solid core doors or clear-glass (not low-E) double pane replacement windows. Use the full net area of the window opening, not just the glass, and don't include the window casing (consider that wall area.)
Air leakage also has to be estimated and accounted for, but is usually WAY overstated in the Manual-J or IBR assumptions. Unless the place leaks air like a tennis racquet through walls & ceilings (which sometimes happens with uninsulated houses) I usually assume 3-5 cfm per window & door.
My boiler set up is a bit more complicated because the boiler has a large label on it with three model numbers - it's not indicated which one is mine.
Looks like the 100/75/60 means GPH.
Lennox
COWB-3-100C
COWB-3-75C
COWB-3-60C
The burner is a Becket AFG - no model number visible.
With an embedded coil for hot water yours is almost certainly the COWB-3-100C, with a 1 gallon per hour nozzle. (Burner techs usually leave a tag with the nozzle model and the raw combustion efficiency on the boiler when performing a tune-up.) The source-fuel energy in a gallon of #2 oil varies a bit, but it's around 138,000 BTU/gallon. Burned at 85% efficiency it means only (0.85 x 138,000 BTU/hr = ) 117,300 BTU/hr went into the heating system, the rest went up the flue. But that's still nearly 3x the amount of heat that your baseboard can emit (and many times the amount of baseboard needed to heat the basement would emit.)
The circulator on the current set up is on the return side, right before the boiler. I would have to move it back up the line a couple of feet to install a second pump and still have room to tee that second pump into the line before entering the boiler. I have room to do that.
With that said, where the water exits the boiler presumably I am allowed to split that line so that the second zone is fed from the same main line, right ? Essentially (in electrical terms) I'm creating a simple parallel circuit that starts right where hot water exits the boiler and ends where the now "used" water re-enters the boiler. The first circulator is plumbed into one of the parallel lines and the second circulator is in the second parallel line ?
Then the TACO SR503 is wired to each circulator, each thermostat and to the current aquastat ?
My basement is half foundation and half unfinished insulated studs. My plan was to build new walls from floor to ceiling, just inside the existing exterior walls and insulate those new walls with R13. Then put 6mil plastic and sheetrock over the top.
This all seems logical to me.....but......weekend warrior
Thanks
Read
the installation sheet on the SR503 on how to wire it up- it's pretty simple. The SR503 turns on the pumps separately by powering them whenever the zone thermostat calls for heat. With most boilers with embedded coils the boiler aquastats operate independently, and are not operated or called by the thermostats directly. There is usually a zone relay or similar control managing the pump.
Read the boiler manual to figure out how yours works. (I might look at it later, if I have the time.)
It doesn't take much pump to run the basement loop- a Taco-007 is overkill, a Taco-003 or similar would be fine. A "smart" pump such as the
AquaMotion AM55-FVL offers a lot of control and can run at very low flow, extremely low power, (for a price), but a Taco 007e running in "green" mode or other not-too-smart but ECM drive pump is the best bang/buck, if complete overkill for the application. It'll use only about 10-15% of the power that an 007 (not-"e") would, and is only about $35 more at internet pricing. If going with zone valves it may be worth springing for a single AM55-FVL or a Taco VT-2218, but even there the 007e is probably still going to give you most of the benefit at a lower price point.