Joined on January 19, 2012
Last Post on December 11, 2013
@ November 1, 2012 12:22 AM in Rinnai vs. Burnham Alpine 95% boilerHow have you arrived at Rinnai and Burnham?
Rinnai's exchanger is fairly new, I would like to see how it performs in the real world before I pass judgement.
Burnham is still using the Gionni exchanger. They require fairly large circulators and diligent maintenance to run correctly.
I only install firetube HX. Triangle tube and Lochinvar both use them. They are an excellent low maintenance exchanger.
@ October 31, 2012 11:54 PM in Load Side Heat Exchange System for Solar Assisted RadiantI would start with a heat loss calc on the house.I would estimate your hot water needs.
Next I would look at estimating the panel output. It is important to compare summer and winter outputs. Generally you are going to produce 2-3x more in the summer. The last place you want to store that extra energy in the summer is under a slab. The house will get hot.
I would do the math 2 ways. Look at the heating and dhw needs in the winter and compare that number to the proposed panel output. I would then look at summer dhw needs and compare the proposed panel output to that. There should be a sweet spot where you are not throwing away too much energy in the summer and are offsetting much of your winter heat loss.
Your insulation looks fantastic. I would steer clear of rule of thumb estimations
@ October 31, 2012 11:35 PM in solar nutYou are doing the math correctly.
I would be careful of the gallons per day number. What is the flow rate at the shower?Is it new construction?
It is interesting that Siggy does not discuss the relationship between production and storage. This link has some useful info.
I suspect your numbers are a bit low.
@ October 28, 2012 11:03 PM in Sewage backup onto gypcreteTim,
I wouldn't worry to much about the disinfecting. I think as far as the gypcrete falling apart, it depends. I have seen quality gyp jobs that tolerate water and tile stripping. I have seen kitty litter gyp under carpet with no exposure to water.
I would play it by ear. and see what it looks like.
@ October 25, 2012 7:47 PM in Inspector comes to his sensesJust as the rest of the US heating world is starting to question PVC venting, they finally excepted it. I see much more PP in the future.
@ October 25, 2012 9:41 AM in Slab insulation....I am looking at the 2006 IRC. Table N1102.1 on page 319 shows r-10 for zones 4-8
Hope that helps.
@ October 24, 2012 11:53 PM in hydronic fan coil GPM vs EWTIf you have a condensing boiler 140 is a good idea. With a conventional boiler , I would run it hotter.
Taco's chart assumes 4 ft/sec. This is quite conservative. Copper is generally good to 5.5 and pex can go higher.
I would be comfortable with the pap or copper at one inch. I would uses pex 1" if the the run is not too long.
Your thinking on the circ power use is right on. You can size the system using 1". I f after you calculate your head loss, your circ is to big, recalc it with the next pipe size up and see if it make a difference.
@ October 17, 2012 8:42 AM in Experience with Field Controls Electric Flue DamperThese dampers are (or are very similar to) the OEM dampers on many boilers manufactured today. They are fairly reliable and will reduce flue heat losses.
What kind of savings are they advertising? I had one that had failed. I bypassed it until I got the new one installed. There was not a huge increase in consumption. Installations will vary. Some flues have a stronger non-fired draft than others.
@ October 17, 2012 8:33 AM in subfloor and additional concrete topping over existing hydronic systemThis sounds messy! I pulled apart a similar system this year. The owner had made a sandwich of the different material you are describing and hindered the system's performance.
In a perfect world you would remove the old concrete, space the tubing off the subfloor and repour the whole thing. You could just pour a self leveling topping coat over the whole thing.
I would stay away from your approach of sandwiching different materials. You are going to greatly reduce your heat transfer.
What is your tubing spaced at? What kind of heat loss does the room have? What are your water temps? Do you know how much insulation is under the slab?
@ October 16, 2012 11:32 PM in Munchkin v. EliteThe Elite and Elite plus are very similar to the munchkin. Just different controls.
The Elite FT is the same exchanger TT and Lochivar is using. I would go with the FT or better yet, just buy a triangle tube.
@ October 15, 2012 12:05 AM in What system pressure for 6,400ft above sea level?I was rereading Modern Hydronic Heating, I get it! Thank you for your patience. I must admit my mind is not as "pliable" as it once was.
I do believe the manual should have said "System pressure should be 15# at sea level, increase pressure .5 psi for every 1,000 feet.
@ October 14, 2012 11:57 PM in Laas mini-therm llIt sounds like you have a failed or incorrectly pressurized expansion tank. You should be able to pull the tank, charge it with a hand pump to you system pressure and reinstall it. If the tank wont hold pressure, replace it.
The second problem sounds like a thermo coupler issue. Does the pilot flame pull away from the thermo when the main burner fires. It sounds like it might.
@ October 14, 2012 11:44 PM in I thought I knewThanks for shaking the tree on this. It is always good to periodically check the assumptions we all make.I wish someone had done the same for double bubble insulation, non O2 tubing and a handful of boilers. It would have saved some headaches.
@ October 14, 2012 11:36 PM in Pump Curve/motor sizing hot water heatingThat does seem like massive circulator for a 4" pipe.
It will also take a significant amount of research to be sure you have resized it correctly. Circulators of that type are quite expensive, you need to be right.
Another approach I like is to replace a large central circulator and zone valves with several smaller ECM circs. It is not possible on all systems but is a great way to reduce circulator energy costs.
Sizing (or oversizing) a circulator for the worst design day then throttling it down for the average day is like hopping in your car, pushing the gas to the floor, then applying the brakes when you go to fast. All the while keeping the gas floored.
It wastes energy and wears out you piping and components.
@ October 14, 2012 4:36 PM in Pump Curve/motor sizing hot water heatingThe pump curve shows how the different impeller, motor and output combinations will perform across a range of conditions.
The part you don't have is the system curve. Every system has a certain amount of resistance.All systems are different. This resistance will increase as the flow rate increases. This curve will start at the bottom left corner of the chart and curve to the upper right. The point that these 2 curve intersect is the gpm the pump will move.
The third question is what are the design perimeters. How many gpm are required to satisfy the emitters in your system.
To confuse things farther, these numbers will change as the load changes. Zone valves open and close and change the load constantly.
Taco's Flow pro University has some tutorials that may help describe this better.
@ October 14, 2012 12:32 AM in Help with delta TI don't think you are going to improve on what you have. It looks like you are running between 4 and 5 gpm on the boiler loop. If you are running 3 gpm on the heating side, you are likely in the 8 -12 range on the infloor when your boiler is at 7.
As suggested, You could experiment with lower flow rates. You could go to low on the circ and experiment with throttling valves. I suspect you will lock out the boiler.
It is true that you will get better efficiency by lowering return temps. You would have to have different emitters to do that. Hugely oversized baseboards and tons of surface area on the radiant floor would help with that.
I think you have designed a nice system that is running well. Aluminum plates are the only thing I would have added.
@ October 13, 2012 3:44 PM in water level tubeFurnaces heat air. They don't use water so I don't think you have one.
Hot water boilers heat water which is usually distributed by circulators (pumps). Some of the older ones have the gauge you describe, they are usually mounted on the expansion tank.
It sounds like you have a steam boiler. The gauge would be mounted on the side of the boiler. A picture would be helpful.
@ October 13, 2012 9:22 AM in Open loop system maintenance, flush ?What temp does your system run at? Low temps are bad. If you run your system above 140 you will be better off.
@ October 13, 2012 9:10 AM in Help with delta TAre you measuring delta T at the boiler or coming off the radiant loops?
What type of radiant panels do you have? What model is the knight? Which circulator is on the boiler? How is the alpha set up? How many gpm does it typically show?
Sorry for all the questions. That is a very nice install. The black background makes it look like art.
@ October 12, 2012 9:30 PM in Radiant Pipe Embedded in Concrete Leaking, Heat Lacking in Some AreasI would start out by looking for a local energy auditor. We have a local non-profit auditor that rents them.
@ October 12, 2012 9:05 PM in Radiant Pipe Embedded in Concrete Leaking, Heat Lacking in Some AreasAn IR camera is going to be your first troubleshooting tool. I think you need to figure out how bad it is. If you have one leak it may be worth attacking. Many leaks would have me looking for "Plan B".
@ October 12, 2012 8:59 PM in Pex-Al-Pex expansion noisesGordon,
I am curious about your install. I would like to avoid a similar problem. What type of plates are you using? Do they touch or overlap?
I think a buffer tank and reducing the differential is a good approach. I would ask triangle tube about this. There are many settings that are not in the manual. Maybe they can help you with the differential.
Another option would be to control the boiler with a 3rd party 0-10 vdc.