Joined on November 26, 2011
Last Post on April 19, 2014
@ December 6, 2012 12:37 PM in Condensing Boilersis 61k BTU/hr -- think PST60. Interesting that they offer a smaller Excellence over there - wish we had that option available to us here.
There is definitely a market for a good 30-40k mod/con here. I'm starting to spec Thermolec TMB's here due to lack of appropriately sized gas-fired alternatives.
@ December 6, 2012 12:22 PM in $4200k for an install of gas powered steam boiler.Top of the system riser where it hits the main(s)?
@ December 6, 2012 11:02 AM in $4200k for an install of gas powered steam boiler.Is it big enough?
Also wondering if there might be something like a bullhead tee above that system riser.
@ December 6, 2012 10:07 AM in leaking radiator valveYes -- remove the spud, then clean both sides of the threaded joint well (a used 1/2" fitting brush works well on the radiator threads.) Apply a band of Loctite to the male threads beginning one or two threads back from the end of the spud. A tad over 360 degrees with an 1/8" bead, or two times around if it's tiny. Thread the spud all the way in. If you use a wrench, use only 2-3 fingers on it. Come back the next day and hook up the other half of the unions. If there's a rubber O-ring on the spud, make sure it's properly seated before you screw them together.
@ December 5, 2012 10:30 PM in leaking radiator valve23 leaking radiators on the fifth floor of a hotel (fourth floor in operation at the time.) Plumbing sub assumed that Teflon gas tape with Teflon paste was good enough for everything.
@ December 5, 2012 10:14 PM in leaking radiator valveIs perfectly safe for hydronics, but it's designed for sealing tapered threads. Most radiators use a British Straight Pipe thread, which needs a different scheme. Straight pipe threads are not something the average plumber encounters here.
@ December 5, 2012 10:08 PM in leaking radiator valveTeflon tape is not recommended for these - use an anaerobic thread sealant.
Myson supplies Loctite 565 with their radiators.
Just started using http://www.fppi.com/products/list/139/pipefit-as-thread-sealant-paste.aspx which is thicker.
Both need ~24 hours before you put pressure on them.
@ December 5, 2012 8:41 PM in Aquasmart, ODR with steam?.Midco LNB http://www.midcointernational.com/products/low_nox/index.htm is under consideration.
Fully modulating steam systems are rather rare -- I don't know of an off-the shelf control that will handle this.
@ December 4, 2012 10:42 PM in A Steam Enthusiast's Outdoor Reset ControlI've been looking for something affordable with a higher temp limit. Nice find!
@ December 4, 2012 6:22 PM in TT Prestige 110 exhaust3" is better if you have the space. From http://www.triangletube.com/documents/1/Prestige%20Vent%20Suppl_PVC_CPVC_PP%20_SS_0412.pdf
2 Inch Vent Systems Restrictions for the PRESTIGE 60, 110 & Excellence.
- Derate the maximum boiler input by 3% when using the maximum equivalent length of 2 inch vent piping on Solo 110 & Excellence 110.
- The 2 inch vent system requires a 1 inch clearance to combustibles
- Use long sweep elbow to limit pressure drop and to avoid excessive vent temperatures.
- In 2 inch PVC vent applications, the first 7 equivalent feet of the vent system must utilize CPVC material.
@ December 4, 2012 1:49 PM in Slantfin &TraneVaporvacWill be much simpler to pipe and should reduce the cost of installation for both labor and materials. If this were a multi-million BTU setup the math could be different. Troubleshooting will also be simpler with a single boiler -- if you need help sometime down the road, a twinned setup would require skills that are not widely available. When I read some of the horror stories here with simple residential systems...
The fully modulating burner should be able maximize efficiency in a way that would simply not be possible with other configs. http://www.midcointernational.com/products/low_nox/index.htm
I'm in southwest New Mexico, but I'd be happy to collaborate with the right installer on something like this.
@ December 4, 2012 1:08 PM in Slantfin &TraneVaporvacI'm going to defer to the real steam pros here (don't shoot me) but it seems to me that you might be able to get away with a 19HE-4, even though it's nameplate rating is only 1316 square feet. That would allow you to use the 500k version of the Midco and get maximum turndown capability. Pickup factor should almost fall out of the equation with full modulation over a 5:1 turndown. Even with simple two stage firing on Vaporstats, you would have fine-grained control over both firing rates.
Wish you were closer to our little corner of the country -- I'd love to do the controls for this.
@ December 4, 2012 9:59 AM in Slantfin &TraneVaporvacand have no doubt done your research, but I think I'd be looking at something like a Smith 19HE with that new modulating Midco Low NOx burner.
@ December 3, 2012 8:57 PM in Short Cycling Triangle Tubeare what you want to focus on during the design phase. Getting them to converge on a value is more important to comfort than the particular value. Once they are somewhat close, you can look at increasing all the radiation across the board, which will reduce water temps and increase efficiency. Bathrooms benefit from a somewhat higher ratio, but the best approach is to simply increase the interior design temp for those rooms. Re-size radiators first, then look at TRVs. They greatly improve the situation for rooms that have considerable solar gain or are infrequently utilized.
@ December 3, 2012 8:11 PM in Slantfin &TraneVaporvacHow many square feet is the connected load? I'm thinking a single boiler with a high-low burner might be a better fit here.
@ December 3, 2012 11:04 AM in Glycol heat lossWould be 7% higher as well, so your 19 GPM becomes 20.3 GPM. Is this piped with a hydraulic separator or closely spaced tees in a primary-secondary configuration? If so (and assuming you don't have overly restrictive piping in that loop) you can usually use a 0010 or a Series 100 with the 399.
@ December 3, 2012 10:34 AM in Short Cycling Triangle Tubebut the intent is the same, and it's the ∆T that matters. Nominally rating them at 215F produced higher output numbers, but you can still correct those. Your numbers show different ratios of losses to radiation capacity for each room, so you're going to have to pick a compromise point. Add a column to your spreadsheet and divide the heat loss by the radiator capacity for each room, then decide which room is going to get more and which will get less. Do you have TRVs on these radiators?
@ December 3, 2012 10:21 AM in Glycol heat lossHas roughly 93.5% of the specific heat that pure water does, so you need to pump about 7% more volume in order to transfer the same amount of BTUs.
@ December 2, 2012 11:04 PM in Short Cycling Triangle TubeNot sure where your 215F AWT came from (Myson uses 176F for their nameplate ratings, assuming a 68F space temp.)
Whatever the source:
Dividing the 10,203 BTU/hr heat loss for the LR zone by the 19,015 nameplate capacity gives a ratio of .537
Myson says a 65F ∆T results in 0.53 of adjusted nameplate capacity, so a space temp of 68F in that space can be achieved with 133F water in the radiator.
I'm not implying this is your system temp, but giving you an example of the process used to determine it.
@ December 2, 2012 10:42 PM in Slantfin &TraneVaporvacJust wanted to say that Slant/Fin did an exemplary job on that manual.
@ December 2, 2012 9:25 PM in Short Cycling Triangle TubeUse the Myson data to determine the water temp at which the radiators match the space losses. This is your system design temp.