Joined on November 26, 2011
Last Post on March 8, 2014
@ March 8, 2014 6:23 PM in Pumping away ? I must have something messed up! HelpThere's a bunch of math, but http://www.amtrol.com/support/extrol_com_sizing.html makes it easy.
@ March 8, 2014 6:20 PM in Pumping away ? I must have something messed up! HelpI make a spreadsheet listing each room with it's heat loss and installed emitter capacity. From that, we can determine what the required system water temp is and also if there are rooms which are likely to become too cold or too hot when the system is running on ODR. For series baseboard, a bit of math is added to the spreadsheet to allow for temp drop along the loop. It's unfortunately rare to find those sized correctly, at least in our neck of the woods. This is a key component of our initial analysis, and from it come recommendations which are reviewed with the owner(s) before a contract is even offered, much less signed. If recommended repairs or improvements are declined, waiver language gets added to the contract to protect us.
@ March 8, 2014 5:59 PM in Sizing a boiler in Watertown, MA10k minimum firing rate - another one for the list. Haven't installed any of those, but am always interested to learn.
I am a big fan both of the Triangle Tube boilers and of the company. Unfortunately, the minimum firing rate on the PTS60 is 16k. This is an artifact of a design decision TT made years ago: Utilize a single control module running the same firmware on all sizes of their boiler -- making it that much easier for installers and distributors to stock spares (an admirable thing in my book.)
@ March 8, 2014 4:48 PM in Pumping away ? I must have something messed up! Helprequires more information, or we will just be guessing. I'll repeat myself:
What is your calculated design day heat loss?
How many feet of what type of baseboard in each loop? How are they
piped? Do the size of emitters in each room have any relation to the room's
@ March 8, 2014 4:43 PM in Hydrotherm Celtic and a 15-42calling Grundfos to see if they still have parts? Someone here ought to have a "clueful" contact on the inside.
@ March 8, 2014 4:36 PM in Sizing a boiler in Watertown, MASince your load is so small, you are basically looking at a choice between the smallest mod/con boilers available from a number of manufacturers. My current working hypothesis is that the design day heat loss should not be less than three time the boiler's minimum firing rate. Most currently available mod/con boilers have a minimum firing rate of 16-17k on their smallest model. Here are some of the lowest minimum modulation rates [in square brackets] of which I am currently aware, followed by their maximum output capacity (in parenthesis):
Viessmann 200-W B2HA 19 [11,580] (64,655)
Lochinvar WHN055 [10,450] (53,250)
Lochinvar Cadet CDN040 [8,545] (37,600)
There may be other options -- I would certainly appreciate knowing about those if someone would share them.
You can size an indirect water heater to your DHW demand -- the maximum firing rates above will come into play there.
Don't give up -- a properly sized, installed, and commissioned mod/con is a thing of beauty that will make you smile each time you walk in the door to a quiet, comfortable house. The low gas bills don't hurt either.
@ March 8, 2014 12:31 PM in Pumping away ? I must have something messed up! Helpcan get expensive when you are paying for the parts. Before you start swapping them, get the system properly designed.
What is your calculated design day heat loss?
How many feet of what type of baseboard in each loop? How are they piped? Do the emitters in each room have any relation to the room's heat loss?
@ March 8, 2014 12:15 PM in Pumping away ? I must have something messed up! Helpfrom the Point of No Pressure Change is what matters. The short version is that you pump away from the pressure tank. The firetube heat exchanger utilized by Triangle Tube has almost no head loss -- I've attached the curves for the 175 and 250 below.
Just because they show a curve for a 0011 doesn't mean you should actually install one. There's a funny bit of pipe detail at the upper right-hand corner of that loop I can't quite see -- is it an offset in the Z dimension with a couple of tees?
I doubt you have more than 40 feet of developed length in that primary loop. If it's 1-1/4" copper, you're pushing at least 24 GPM and 6 FPS there. Believe it or not, I'd probably use a 006 for that.
If I were starting from scratch, I'd dispense with the primary/secondary piping altogether, install two zone valves and use a single ECM smart circ.
@ March 8, 2014 11:38 AM in Pumping away ? I must have something messed up! HelpI see two green pumps, presumably Taco 0011's. One is on the primary loop, the other off a set of closely spaced tees, probably feeding your baseboard.
I see one red pump, presumably a Grundfos, off a second set of closely spaced tees. What does it serve?
If all you have is one zone, it's quite likely you don't need primary/secondary piping at all. How much pipe head does that zone have? How much fin tube of what type? Was a heat loss calculation done?
@ March 8, 2014 11:28 AM in Pumping away ? I must have something messed up! Helpdoes that feed the indirect? If so, try powering it down and valving off both lines.
0011 is an unusual selection for a primary loop -- what size is the boiler?
@ March 8, 2014 10:58 AM in Pumping away ? I must have something messed up! Helpis 69.3 feet of head. The 0011 maxes out around 31 feet. Unless you somehow managed to pipe the two pumps in series, and even that is dicey, I'd be looking at a leaking indirect or tankless coil.
@ March 7, 2014 10:54 AM in Newbie Hydronic questionsStart with a room-by-room heat loss. Then measure your existing baseboard and see what water temp it needs to be happy on a design day. If that number is high, you might consider augmenting or replacing it at some point. If you're going to use panel rads for the rest of the house, I'd suggest sizing them at 140ºF if practical.
Does the bathroom have any exterior walls? If so, electric radiant could cost a bit to run. Back to the heat loss calc -- be sure to bump up the indoor design temp on the bathroom a bit, say 75ºF. Radiant towel heaters are one of the finer things in life, even in summer. The electric ones cost about 1/3rd of what the hydronic ones do, but they can run all year without firing up the boiler. If that bath has exterior walls, you might want both heat sources in it.
@ March 6, 2014 2:48 PM in tenant heat meteringhttp://www.badgermeter.com/Industrial/Impeller-Products/Sensors/380-Series-Btu-System.htm
@ March 6, 2014 2:47 PM in TT PE110 longer run timesgenerally produces the most stable indoor temps, and minimizes thermal stress on both the boiler and the system. Since it is heating with the lowest possible water temps, it also maximizes combustion efficiency.
Minimal setbacks (of a degree or three) seem to work OK, espeically if they are done via the supply temp rather than by turning off the boiler. The best answer is ODR with indoor feedback, which is unfortunately somewhat rare here in the US.
@ March 6, 2014 2:37 PM in computer room heat gain questionDepends on the activity level http://www.engineeringtoolbox.com/persons-heat-gain-d_242.html
@ March 6, 2014 12:36 PM in High Duty baseboardI'm not familiar with that brand, but several manufacturers offer heavy duty or high output variants. The length limit for a 3/4" circuit would depend on the flow, which would in turn depend on the ∆T for the loop.
@ March 6, 2014 12:27 PM in TT PE110 longer run timesis far easier if you remove the thermostat from the equation before you start. Raise the setpoint on the stat to 85ºF or so and leave it there until you can maintain a consistent indoor temp using just the ODR settings. Then drop the setpoint to 2º-4º above your desired space temp as a high limit control.
If you intend to use the stat for space temp control going forward, a PWM stat helps (as mentioned above) but you should also raise the ODR curve a couple degrees at each end so the stat has something to work with.
@ March 6, 2014 12:01 PM in Fuel use question?I make sure to collect them from the closest (or most similar) PWS. I go to www.degree-days.net, download daily data for the previous two (or more) months, then prune the data so it matches the meter reading or tank filling dates and sum those up.
Two things you need to consider: One is base temp -- for newer, better insulated houses, 65ºF is not a good assumption. The other is non-heating appliance use. Add up the gas or oil use over 3-4 non-heating months and divide that by the number of days to get an average daily use number and subtract that (multiplied by the days in the billing period) from the usage during the heating season.
@ March 6, 2014 11:32 AM in Newbie Hydronic questionsYour system will be simpler if you can design for a single water temperature instead of two. Size the RFH first and then pick radiators using that supply temp.
Radiators (either panel type or cast iron) work far better with low water temps than fin-tube baseboard will.
With a mod/con boiler, lower return water temps produce higher combustion efficiency. Lower firing rates (burner modulating down) also produce higher combustion efficiency. Condensation happens as a side effect of this higher efficiency. There is no "quantum leap" when condensation starts -- but instead, a continuum of roughly 86% to 98% depending on the conditions above.
@ March 6, 2014 10:52 AM in Rinnai RH180 or 100 Gallon Atmospheric?I'm curious about the piping layout you used to accomplish the switching.
@ March 6, 2014 10:50 AM in Free solar ???????http://en.wikipedia.org/wiki/Power_purchase_agreement Not all states have enabling legislation yet.
@ March 6, 2014 10:15 AM in computer room heat gain questionAre not simply a multiplier of volts and amps. There's a phase angle component (called power factor) which requires sampling over time and averaging. Your meter will work fine for stable DC, but will not give you the right answer -- especially for nonlinear AC loads like a computer power supply.