Joined on January 19, 2012
Last Post on December 11, 2013
@ December 23, 2012 12:47 PM in Adding honeywell ra889a to system with external transformerI used to seriously over think electrical circuits. I picked up a couple of Carol Fey books and it all started making sense. The thing she says that I repeat to myself when I get confused, is that everything in a simple electric circuit is either a power supply, a switch or a load. Your boiler TT is a power supply on one side. It is looking for a switch to connect it to the load on the other side. In other words it doesn't matter which way you connect it. The relay is just a switch.
Thanks for the link.
@ December 23, 2012 9:38 AM in Adding honeywell ra889a to system with external transformerI don't see any issues on the wiring side.
What program are you drawing with?
@ December 23, 2012 9:27 AM in Electric baseboard vs propane fireplacesIt depends on you fuel rates and the efficiency of the heaters. Check this out www.eia.gov/neic/experts/heatcalc.xls
Your electrical efficiency should be about 99% The propane maybe 60%?
Plug in you local rates and there it is.
@ December 23, 2012 9:15 AM in Carrying capacity of copper pipeOk,
So this is more of a theoretical conversation? If you do not know the approximate length and output of the emitters on the loop how would you know the target GPM? Maybe you are pumping to much water? I think you need to figure out what your heat loss for the rooms being heated and compare that number to the available radiation in each room. It is also important to note which emitters are on the supply side of the loop and which are on the return. This will tell you what temp and how much water you need to deliver.
Just because some knucklehead oversized the boiler, that doesn't mean you need to overheat the house, wear out the pipes, and spend a bunch of money on circulators.
If you needed to go to the store for a gallon of milk and the only car in the driveway was a dumptruck, would you have to fill it with dirt for the trip? No, you would just drive it and hope to find a parking space.
@ December 22, 2012 10:31 PM in Carrying capacity of copper pipeI have been reading this post and am confused. How many feet of actual baseboard do you have? Is it 3/4" single pipe (one pipe running through the rad)?
@ December 22, 2012 6:09 PM in Adding honeywell ra889a to system with external transformerYup that's it.
I would wire all the controls and transformers to the same 120v circuit. It might save someone a headache on modifications down the road.
@ December 22, 2012 5:05 PM in Piping QuestionThe pipe sizing of the primary and secondary loops should be based on the gpm requirements of the loops.The gpm needed is based on the number of btu's being transported and designed delta t. The conversion factor link at the top has some good guidelines.
In the system you describe your header is likely sized as a "low head loss" header. This insures even distribution across the zones. I am thinking your 112k boiler will work just fine with 1" piping although some manufacturers will call for 1 1/4" Check your manual to be sure.
@ December 22, 2012 4:36 PM in Adding honeywell ra889a to system with external transformerI think you're all set with the wiring of the transformer to the t-stats.
If you take the end switches from the 2 zone valves off the boiler and connect them to R(T) and W(T), this will enable the pump relay. You have 120v power wired to COM and the pump wired to N.O.
When this happens the relay will close terminals X1 and X2. If you connect these to the boiler TT terminals you are all set.
@ December 21, 2012 8:10 AM in Wax on, wax off, wax on...I am thinking the short flue combined with a vent hood rather than a barometric damper is giving you an inadequate draft. This makes it look like you have good efficiency. A bit rich for atmospheric. The co is .the red flag. When you block the hood the draft improves and it turns out you are to lean. Just add about 20' of insulated flue and you should be all set.
First cup of coffee.
It looks like the fence could use some paint...
@ December 19, 2012 12:25 AM in Natural Gas Tankless Heater and plumbingYou are correct to be suspicious. What your plumber is doing is running an undersized line at high pressure. Then he is regulating it back down at the appliance. If you have the btu rating of the appliances and the length of the runs, someone may be willing to help you calc this. In my mind this is crazy. Opinions may vary. 27.7 inches of wc = 1psi
@ December 18, 2012 8:54 AM in Finding Private MessagesWhen someone clicks "contact user" on your name, You will get an e-mail saying "someone on the wall...." You then have the option to send them a message from your own e-mail account.
@ December 18, 2012 8:47 AM in where to put electric mat radiant heat in kitchenI agree with Gordy. What is the primary heat? In most areas electricity is not an affordable way to heat a space.
If it is a supplemental heat source, I would do the areas where you walk. I would also consider a slab sensor and a timer. The goal in this case is to make the floor feel warm during certain times of the day
If you intend to heat the house, you really need to do a heat loss calculation on the room and size your heat accordingly.
@ December 17, 2012 11:24 PM in Garage Slab Radiant Heat SourceYour heat loss is certainly not 41 btu/ft in a well insulated garage. It is probably 1/2 that. You should do a heat loss calc. As mentioned hot water heaters are not designed for radiant heat. That being said it does comply with code in many areas and it is only a garage. The watt rating on an appliance times 2.93 will give you BTU/hr. Most electric water heater have either 4500 or 5500 watt elements. They are factory wired to fire only one element at a time. Some allow you to rewire and energize both.
@ December 16, 2012 11:36 AM in Smart buffer tank?Boiler buddy is one. It provides hydrolic separation as well.There are plenty of folks using electric water heaters as buffer tanks.
@ December 15, 2012 7:12 PM in Smart buffer tank?I think you are the right track. You are going to have a heck of a time generating domestic water when you boiler loop is at 120. I think from a control point of view you are making work for yourself. Mod cons come with everything you need to do outdoor reset and domestic priority.
I think it would go with a smaller domestic tank (smart 30 or 40) and use the money you save to buy a buffer tank. for the heating side.
@ December 14, 2012 8:44 PM in Smart buffer tank?What you are describing is a reverse indirect. You cannot do it with a TT Smart. The outer (boiler side) jacket is steel and cannot be exposed to domestic water.A coil design exchanger like heat-flo and others would work well.
I think what you are trying to do would work well with a non-condensing boiler and injection mixing. A mod con boiler would have trouble keeping up with the domestic load when it it is firing at the lower temp range.
@ December 12, 2012 11:51 PM in Any electricians want to help me out with a question?To do it the way you describe you would need a load center. Why not just install another timer on another circuit? If you absolutely have to have the one timer you could install a double pole relay off the existing timer and control 2 separate circuits.I think 2 small circuits are going to be easier than 1 large.
@ December 12, 2012 12:12 AM in Zone ValvesYou should not need check valves. Not flow can occur with the valves closed.
@ December 12, 2012 12:06 AM in Hot Water Volume Advise...Modern hydronic heating is an excellent book and is available on this sit. It is worth every cent.
As for your project.. What type of facility is it? Public restrooms or condos? What are your specifics propane limitations? What other loads do you have?
@ December 11, 2012 10:57 PM in coyote vs road runner applicationOk,
I think you actually could do it. It is however an idea that could only be dreamed up by the military. If you sized a pressure reducer with a big enough spring and enough capacity, I am thinking could use it to support the weight of some of the water.
Overall the pressure at the 90' column will 39 psi (that new conversion table sure is handy). If you are shooting for 22 psi at the boiler you need to hold back 17 psi. I see 2 major problems with the plan. First, you circulator will have to overcome the additional 17 psi plus the head loss of the check valve, pressure reducer and the regular system loss. It will cost more to buy and run than either of the other solutions. Second, If either the check valve or the PRV fails, you boiler room will be flooded with very hot water and the heat won't work.
Thank you for the most interesting puzzle,
@ December 11, 2012 4:07 PM in coyote vs road runner applicationThat won't work. The easiest would be if you can increase the relief valve size. If not just do a heat exchanger.
@ December 10, 2012 11:13 PM in Heating pex tubingPex-a or pex-al-pex are probably your best choices.
I like uphoner hepex with propex fittings.
Like Steve said o2 barrier is a must.