Joined on January 19, 2012
Last Post on July 30, 2014
@ June 22, 2013 9:54 AM in Radiant - GypcreetKen,
I am guessing you have finished ceiling below. Can you blow in insulation?
First off bubble wrap will not work in a radiant system. The "reflective" value only works in an air space. Even then it is suspect and not allowed by most codes. The other thing to look at is the compressive rating. If the product will compress under load, the gyp will crack. If you can afford the space rigid insulation would work.
Why are you looking for a high mass system? I would take a hard look at a product like warm board. You can put rigid insulation under it and eliminate the thermal "flywheel effect"
@ June 22, 2013 9:40 AM in Multiple ODRs?Tough one,
I love the TT boilers. This is their biggest weakness.
Tekmar has great stuff that will always run the boiler at the lowest temp, it will mix down your slab when needed. They are not cheap.
The thermostatic valve will give you a good max protection but will not give you ODR when both zones are calling.
A non thermostatic will allow one zone to lag the other and have a reset curve. You would have to always run the boiler at the the higher temp costing you some efficiency.
You could use an odr mixer and keep the boiler the way it is. This solution may take a little longer to get dialed in but would work well. It would be a bit "messy" from a style point of view but would be inexpensive and work well.
@ June 21, 2013 2:00 PM in Sloped ceiling insulation problemThanks,
That is a good read. I will throw it in the file. These things are so handy when you are trying to explain concepts to folks.Fine homebuilding also did a great one on ice dams.
@ June 21, 2013 1:13 PM in Sloped ceiling insulation problemRob,
What I described does work. A great deal of attention needs to be given to the details.
@ June 21, 2013 1:06 PM in Issue - Condensation?Is your dryer vented to the outside?
Why are you draining your pipes?
Try putting a cheap humidistat down there.
@ June 21, 2013 10:23 AM in Sloped ceiling insulation problemRob,
My understanding of this is that if you fill the void without 100% air sealing and the correct r value, you create a condensation issue which leads to rotting ect.
If you use the correct amount of closed cell foam insulation based on the relative humidity and design temp in your area you eliminate the condensation and have the best possible assembly.
It is kind of like, why does moisture form on some refrigerators and not others in varying climates?
I may stand corrected on some of this, but that is the general idea.
@ June 21, 2013 9:13 AM in High vs Low efficiency gas boiler?Homeowner1,
I am truly happy that you love your boiler and have had no issues with it.
I am not sure why you take it so personally when the pros on this site discourage people from buying one due to it's overall poor track record. Do you think they are making it up? It is very expensive for a contractor when they install a lemon. Many of the navien units were lemons. This is not the contractors fault, however they lost money trying to warrantee a faulty product.
As for the 10 to 1 turndown ratio. Going from 5 to 1 to 10 to 1 is an easy thing to claim, it is a difficult thing to do. Anyone who has either researched the subject or used a combustion analyzer to verify these claims will tell you that navien is stretching the truth at best. The excess air goes to pot and the efficiency suffers. This is a fact. Standout companies like Triangle Tube will tell you that this is why they do not offer 10 to 1.
It is great that you have had success with your boiler. Your opinion is based on your experience with your boiler and the marketing hype from Navien. And yes it has saved money over your old system.
The people you claim "hate" combi's on this site, have a significantly different skillset and level of experience.
@ June 20, 2013 5:46 PM in outdoor reset for radiant floor heatIt sounds like an unusual setup. Are either the boiler or the radiant loops tied into the domestic water or are they isolated?
It sounds like you need to vary the temp in the tanks based on the temperature outside (outdoor reset control).This will help you apply the correct amount of energy to the floor based on your actual heat loss a any particular time. There are quite a few ways of doing this. If you post a picture or drawing of your system we should be able to point you in the right direction.
Depending on how much solar gain you are experiencing, you may want to consider Tekmar TN4 controls. The TN4 system has the ability to anticipate an overshoot. They work pretty well. With a high mass slab it is very hard to completely eliminate overshoot.
@ June 20, 2013 4:41 PM in Which boilerYou should use the heatloss number to size the boiler.
The attached load will come into play if you use outdoor reset, particularly in a condensing gas boiler.
You are stuck with oil, yes?
@ June 20, 2013 3:31 PM in High vs Low efficiency gas boiler?As usual the answer is "it depends". Although your baseboard heaters were designed for 180 degree water, they may not need anywhere near that much to heat your home. This is particularly true on warmer days. A heat loss calculation of the house should be done on a room by room basis. This calc should be compared to the amount of radiation you have installed. If this study indicates that the system water temp can be reduced to less than 140 for the majority of you heating system, a condensing boiler would be a could call. The temp would be reduced automatically by the ODR controls in the boiler.
Here is a great presentation www.pugetsoundashrae.org/PDF_files/AshraeCondensingtechnology.ppt
I do not think this forum is against combi systems.
Their good brands and not so good. Combi's work better in some applications than others.
@ June 20, 2013 9:38 AM in washing machine drain hose problemThe supply hoses present a much greater risk. The stainless braided ones are a good idea.
Even if (very unlikely) the waste line were to plug, it would only dump the contents of one load. A burst supply hose will flood the entire basement.
Even if you were to successfully seal the drain line, The waste water would just find another path. You would likely see it squirting out a sink or shower drain elsewhere in the house.
Good supply lines and a securely attached drain hose and you should be all set.
@ June 20, 2013 9:03 AM in Same hotel room strikes again?Jim,
Why are pool heaters such a risk?
Is it because they run at lower temps and the condensate destroys the flue.
Are they installed by pool techs that don't understand the dangers?
@ June 20, 2013 12:48 AM in High Efficieny Gas Boiler RecommendationHenry,
I love the turntable. Where is the spring?
I have always wanted to pull into the garage at 60mph. the energy would be absorbed by a giant spring. The car would be spun on a turntable and be released at 60. No wasted energy. Your project is so close.
@ June 19, 2013 5:22 PM in makeup water problemIs the fill on the suction side of the circs? Where is the expansion tank located? Do you have a relief valve?
I was thinking that if the circ is pumping towards the tank. It would lower pressure on the suction side causing the fill valve to open. When the circ turns off the pressure would stabilize at a higher pressure triggering the relief valve.
Just a thought,
@ June 19, 2013 5:15 PM in DumbI had a rep that changed supply houses. When you called and asked for him at his old job they would give you his phone number at his new job rather than introduce you to your new rep. Crazy stuff!
@ June 19, 2013 5:08 PM in Which boilerYou have no other choice but oil (or you own an oil well)?
Here is a handy tool to help evaluate fuel costs.
As far as sizing goes, the heat loss number is the one to look at. You certaininly do not want an oversized unit, particularly a low volume oversized. The short cycling will be amplified.
@ June 19, 2013 8:45 AM in in slab radiantJoe,
Check out this www.pugetsoundashrae.org/PDF_files/AshraeCondensingtechnology.pp
The trick with your system is to get the return water below the dewpoint. Your cast iron rads may perform better than you think at the lower temps. The simplest piping design would have the entire system designed for the same boiler temp curve. You will get pretty good efficiency .If the coldest design day can have return temps less than 130.
Your garage floor would be a bit overheated at that temp, the warm board system would depend on the design. A simple non-thermostatic mixer would allow you to have a zone temp that simply "lags" the boiler ODR curve.
I did not realize that you had a condensing boiler. That changes things.
@ June 18, 2013 1:33 PM in Hard or soft: what water to feed into Hydronic heating systemI would check with tech support to get the definitive.The salt can be worse on the stainless than hard water.
In the past we have just filled buckets with treated city water. I guess you could buy drinking water also
@ June 18, 2013 11:01 AM in Hard or soft: what water to feed into Hydronic heating systemLochinvar should have a water hardness number in the manual.
Depending on the size your system, I think it would make sense to truck in a few 5 gallon buckets for the original fill.
@ June 17, 2013 11:19 PM in Triple Aquatat RElayYou really need to post the model of the boiler and a diagram of how it is wired.
@ June 17, 2013 6:44 PM in Delta t ...... The obsessionJean,
'It sounds like you have your shortcycling under control. I suspect there is a flaw in the way you have measured your delta t on the system side. It would be impossible to get the delta t you describe without short cycling.
Delta t should be carefully considered at the design phase. Not obsessed in the real world.
Glad your system is running so well after the tweaks.