Joined on October 25, 2004
Last Post on April 18, 2014
@ April 18, 2014 6:49 AM in Mid range boilersI would look at the US Boiler MPO 3 pass. Good quiet and efficient. I also like the plug in ODR control. Easy to install.
@ April 11, 2014 10:13 PM in Questions regarding the main vent and auto water feeder that cuts off the boiler every 10 minutesI am not commenting if I like or dislike the 10 minute run time but the reasoning behind it. In all honesty there is not need for it on the atmospheric gas boilers due to making steam slower. The need was thought yo be needed on the oil boilers due to making steam very rapidly.
Here us the reason behind it, foam. When a boiler is foaming the probe will still operate as it is in water.nit could cause dry fire. The delay allows the foam to collapse and/ or allow water to come back to the boiler.
@ April 10, 2014 8:17 PM in Is my steam boiler way oversized?In the meantime doesn't that boiler have a low fire hold switch. That would reduce it by about 40% until the gas comes and should still heat well.
@ April 7, 2014 8:23 PM in Wet/Dry based boilers?Don't forget there are also wet leg boilers, water on both sides and back but not beneath the flame.
Than we have water tube boilers.
@ April 5, 2014 9:15 PM in Boiler Bypass and otherThe bypass would only need valves due to since boiler water volume has been reduced the boiler bypass will protect the boiler. It's all about flow. New lower water volume boiler all you need to do is reduce the flow within spec's. Get the average water temperature through the boiler above 140f.
You could choose the US Boiler ESC, ES2 or Series 3 which can get 110f back without a problem. Probably wouldn't even need a bypass due to zoning.
@ April 3, 2014 9:11 PM in Burnham gas conversionA contractor friend checked with a local lawyer a few years ago and he stated that since the manual specifically says For #2 fuel oil only, do not burn gaseous fuels (not exact wording) it did make it a legal issue since it was in print.
@ March 30, 2014 7:29 AM in Boiler Piping questionsThe one quick thing I see wrong with your proposed drawing is that your one Tee for system riser will be between two boiler risers. You never want a system riser between your boiler risers all your system riser should be after the boiler risers. Of course the second is no pipe insulation.
@ March 30, 2014 7:23 AM in Main VentsThe bigger problem that I see is the Bullhead T on the supply that should be broken into two risers. It's kind hard to see from the picture but it looks like the tee going up to the system riser is between two risers coming out the boiler. Both of these are no no's in steam piping.
@ March 30, 2014 7:15 AM in steam section broke at the top.The bigger problem is why does this happen. Usually happens due to excess water being fed into the boiler thank car rides attaches to the iron. Check your vents, check your valve packing for leaks and check for any underground returns that may be leaking
@ March 26, 2014 7:17 AM in Sizing a boiler in Watertown, MAThe Alpine at least you can turn down the input rpm's to match the heat loss and leave the fan rpm's higher for the domestic if you want. Almost like two boilers in one. They do turn down to 16k input which may be about 14k output.
The other thinkg I like about the newer version is the low fire hold for two minutes. Any Alpine produced since the beginning of this year has the option of choosing number one on the response speed, in the central heat menu, when the boiler fires it drives it into low fire for two minutes. this allows time for the water to circulate and hopefully coming back to the boiler. Then the boiler only modulates up to the required rpm's. The same can be for DHW but it is a one minute hold time.
The new IQ control you will be able to input down to the 1000 btu heat loss but the boiler will still only fire at it's minimum, say 16k. It will total all zone demands and not release from minimum input until the total of zone demands is above the minimum firing rate.
The biggest problem with oversized mod/cons is not going low enough. Sure they modulate back when firing but the most efficient operation is the bottom side of the operation. If you have a 16k zone and the boiler modulates to 16 that is great. But if the minikmum zone is 16k and the boiler only turns down to 30k that is where you are loosing the most efficiency. So the statement that over sizing is not as important could be no further from the truth.
@ March 25, 2014 10:46 PM in New boiler supply/return questionThis is a pretty unusual circulator for baseboard hot water.
What is the cycle time on the boiler?
@ March 24, 2014 7:54 AM in My first ALPHA pumpSnowmelt - I like the Sentry zone valve. It works rapidly after a short charging cycle which is usually a few seconds. Very quiet and easy to wire and install. The powerhead comes off with a push on a tab and unplug the wiring. Insert new head and plug the wiring harness back in.
The reason I used the Alpha insteqd of the Taco Bumblebee is Burnham is having a special on their cast iron boilers. Order with the Alpha and there is no up-charge. So I could get one to try with no extra cost above what I would have paid for the Taco 007.
Tom - Tried all the settings. If they want you to try high speed first they should default to that. I think it is just a dud. Not a good first impression. Just a green - -.
BTW Taco resolved that noise issue.
@ March 23, 2014 8:11 PM in My first ALPHA pumpI have read many good posts about the Alpha pump. I had a job with 2 zone valves and an Indirect. The boiler is a cast iron 40K. I used 2 Taco Sentry zone valves, Alpha pump and a separate pump with IFC.
I must say the first experience with the Alpha was less than positive. I felt the wiring was a bit tough as I have big hands. After getting through that turned on the boiler. All the lights came on on the pump once the zone valve opened. Went into the default auto adapt. About 30 seconds later I got 2 dashes on the pump display. Read manual check for flow, voltage locked rotor. Recycle power.
Re-purged and the same thing. The display says 1 watt and 0 gallons.
After trying different things I put one of the old Taco 007's in place of the Alpha. Did not even re-purge and all took off and heated.
Not real impressed with the first one.
@ March 20, 2014 8:38 PM in boiler bypassThe manufacturer wants a boiler bypass why would you disagree with that? You are putting too much emphasis on return water temperature as many do. To quote Gil Carlson who invented the boiler bypass. Thermal stress and flue gas condensation is a result of extremely cold water entering the boiler or cool water at a high flow rate" The return temperature is not as important as the flow. We should be trying to get the average water temperature of the boiler above condensing temp. When the boilers switched to low water volume the bypass switched to a boiler bypass. System bypasses are for higher water volume.
I agree that with an old gravity hot water system you definitely need boiler protection.
How about p/s and using a delta T pump for the boiler secondary piping set to 30 - 40 delta-T.
@ March 18, 2014 10:07 PM in ConfusedNot sure what the difference between a hydraulic separator and low loss header is. Any help here?
@ March 18, 2014 9:55 PM in sizingDiameter is more about flow and length is more about resistance. Generally and simply speaking if you need to move 7 GPM in a pipe 4 ft long you need 1 " pipe. If you need to move 7 GPM in a pipe 200' long you need 1" pipe but the added resistance requires a larger pump.
This example is exaggerated but I think makes the point. 7 GPM with 200 ft pipe you would probably jump to 1-1/4" pipe to use a smaller pump and less chance of hydronic harmonics.
Pushing or pulling water in a boiler does not change the pressure so no cavitation will exist. If you push into the boiler with a static fill of 12 psi the boiler pressure is 12 psi. If you pull out of the boiler as long as the circulator is after the expansion tank connection the boiler pressure will be 12 psi. The difference is pushing into the boiler the upstairs system pressure will drop and pulling out of the boiler again assuming you are pumping away from the expansion tank will add pressure to the system. You always need at least 4 psi at the high point of the system.
@ March 18, 2014 6:57 AM in sizingSize pipe according to flow requirement of duct coil. The different sizes sometimes is to change the velocity of flow such as in high efficiency boilers. Flow in heating pipes are normally designed at 2-4 ft second and some newer boilers and even indirects are upwards of 5.5 ft second.
The coil manufcaturer will normally specify multiple flow requirement for multiple btu outputs.Choose the one you need and size the pipe for that.
@ March 17, 2014 6:16 PM in boiler bypassDo you need boiler protection?
Maybe not. We only need to get to average water temperature in boiler of 140f within a reasonable amount of time.
How much is boiler over sized? Notice I did not ask if boiler is oversized. Most existing boilers are easily 50% to 100% oversized. If boiler is oversized your concerns are lessened.
What type of radiation?
How many heating zones?
I would forget the idea of the zone valve in a boiler bypass. You stated a boiler bypass and your comments are leaning toward a system bypass. A boiler bypass will bypass water around the boiler back to the system. This is the proper bypass. Due to lower water volume boilers the bypass changed from the system bypass when the boilers had larger water volume. Commercial cadet iron boilers still can use system bypasses.
A system bypass will pull hot waster from the supply to the return.
A boiler bypass will use cool return to hot supply. More beneficial. Keeps system flow rates higher, reduces flow through the boiler so water can get warmer faster. Boiler bypass valve is usually wide open all the time. You reduce flow in the boiler with a valve on either supply or return and the boiler.
@ March 17, 2014 5:52 PM in Mod/Con Heat Exchanger DesignsEven though we don't agree on the controls sounds like we agree on the heat exchangers.
@ March 17, 2014 11:39 AM in Confused about "pumping away" and Knight WH installationME hope you bid that nickel into the job.
@ March 17, 2014 11:29 AM in Mod/Con Heat Exchanger DesignsThe whole Gianonni bashing is on all the really old stuff. The funny part about it back then they were not having the problems in Europe just when it was introduced in the states. Our systems are different and normally run higher temperatures.We as an industry have memories like elephants instead of forgiving souls.
In my area up to about say 2-3 years ago you could not hardly give away a Grundfos circulator due to their starting problems from the eighties. The truth of the matter is when problems exist the manufacturers make changes and the Gianonni heat exchanger has gone through multiple changes for upgrades and improvements over the last decade plus, just like everyone else's product.
Admittedly they are a higher pressure drop for circulators but also offer more fireside heating surface than most.
Since your choices are limited what else is there to look at. The control. Who offers the best control features needed or not. Remember this is programing and adds no cost to the control.
All the boilers are about the same efficiency so that can be removed in the decision making process especially since the boilers are not the rated efficiency during most of the operating period. They only meet the rated efficiency with 120f return and 140f supply and proper flow rate, proper sizing etc.
So let's look at the newest Alpine control.
They have changed the PID so it modulates down faster. The big thing is on boilers manufactured this year if you go to central heat paramters they had a response speed which was adjusteable from 1 - 5. One was slower modulation and 5 is faster modulation. Now they have added if you press 1 the boiler will light off and go into a low fire hold for 2 minutes and modulate up to where it needs to go. . Between that and the new IQ zone panel they introduced I guess they are saying why ever fire higher than you have to. They also can do a wireless OD sensor now.
If you did not see the new IQ zone control at the Javits Center in January they had on display and will be introducung a zone control that is pretty cool. We know the largest fuel savings we can off the end user is the proper sized boiler and probably the second highest fuel savings is system efficiency. All mod/cons already off ODR to assist in raising system efficiency. This new control is a 4 zone expandable to 4 panels (16 zones) by cat 5 cables. You can name each zone and each zone will show a cycle rate. The neat thing is you can input the BTU loss for each zone and the boiler will limit it's firing rate to that BTU input or minimum fire. They will allow you to put in real low numbers, way less than minimum fire but of course the boiler will only go as low as minimum fire. It will keep adding togather the inputed btu's and stay at minimum until the total is higher than minimum input. Once the imputed btu's is above the minimum input the boiler can still modulate between that number and minimum.
Since boilers and boiler controls are close I feel this is more exciting than boiler efficiencies since they are so high and very close. The next step had to be addressing system efficiencies. Good job guys!