Joined on March 11, 2004
Last Post on November 21, 2011
@ November 21, 2011 9:19 PM in Honeywell Prestige HD thermostat question...... then again, there is no deep recovery going on. With a high-mass house, I didn't see the point. Plus, the small kids have us up at all hours, it's best to keep everyone comfortable while getting an AM snack.
I wonder if, with enough research, one could decode/hack the contents of the XML file to figure out a way to allow a 1-stage radiant heating system + an AC system to co-exist peacefully on this Tstat. I guess the Prestige II has addressed this issue (good for them!) right out of the box. Who wants to volunteer to change the relevant settings a few times and download the XML settings each time to see what entries changed?
@ November 8, 2011 7:58 AM in Honeywell Prestige HD thermostat question...... the only likely difference between the two models is a different firmware... so if Honeywell were to offer a firmware upgrade, that would be great - and a potential moneymaker for the trades also - "hey I can upgrade your tstat for $50...".
But I'm not holding my breath for that to happen!
@ November 4, 2011 1:38 AM in Honeywell Prestige HD thermostat question...I tried that approach initially and it didn't work on all of them (which in itself is weird, right?). The G wire kept getting energized on most thermostats whenever there was a call for heat.
Setting the unit up for two stages works great since one can select that the fan doesn't come on (all of the thermostats were explicit about this) when on stage 1. That still allows the fan to turn on when there is a call for humidity.
As for transferring installer settings, one interesting thing I discovered was that the XML file that is used to transfer those settings varies by firmware. Thus, one thermostat (older, newer? have to look at the mfg code) reported that its firmware was not compatible with the installer settings I had tried to transfer from another thermostat.
Does Honeywell offer firmware upgrades to its installer base? I wonder since there doesn't seem to be a firmware upgrade button in the GUI, on the other hand, the thermostat auto-launches whenever a USB device is attached - i.e. it could autorun a payload at that point.
Thanks again for the suggestions. I appreciated them.
@ October 29, 2011 8:29 AM in Honeywell Prestige HD thermostat question...Per Honeywell, this model may only be installed by trained, licensed professionals. And these folk should have the answers I seek, even if they didn't, which is why I contacted Honeywell in the first place. The residential help line cannot help people like me because of liability reasons, or so they say. I wonder whose liability? Surely it can't be any liability regarding the use of a thermostat, since they'll happily support a customer on any other thermostat than the Prestige HD.
They were nice enough to include a number for my HVAC professional to call them directly. But thankfully, I muddled until I found a way to support hydronic heat and a whole house humidifier and automatic changeover and so on is the following:
Declare the system as a two-stage conventional heating system even if it only has one heating stage. Next, program the thermostat to only have the fan come on when it hits stage 2. Lastly, program the unit so that the fan comes on for the humidifier. Problem solved but not as intuitive as a "hydronic heat and AC" menu selection in the main setup menu, eh? :-D
Anyhow, perhaps other thermostats have the same kinds of setup "tricks" to allow mixed heating and cooling system use.
@ October 28, 2011 10:38 AM in Honeywell Prestige HD thermostat question...Nifty thermostat, lots of control and retrofit possibilities via its many iterations, wireless options, etc. However, I don't see how this unit can be used to automatically accomodate hydronic heating systems that share a house with an AC system.
While the thermostat calls for heat just fine, there does not seem to be a way in its installer settings to select a hydronic heating / ac cooling system. As a result, every time heat is called, the thermostat will also energize the "G" terminal, turning on the fan. Now, having a fan running is not the end of the world, but it's also not necessary in the wintertime.
So besides manually turning the fan off (definitely an option), is there a way to get this thermostat to play nice with hydronic heating / AC cooling systems automatically? Is there perhaps a firmware update that addresses this issue?
@ September 24, 2011 10:20 AM in East Coast IBC Boiler Experiences, anyone?At the time, IBC were not represented by RST and hence had no real presence on the East coast for spare parts, etc. Two months later and the decision would have been a lot more difficult!
I have been very happy with Mr. Vitodens but with RST backing IBC now, I see no reason to take a very close look at their offering as well. The AFUE of the Vitodens is higher, as I recall but the main benefit of modulation is present in both units. Plus, some of the IBCs have a wider modulation range, which is pretty nifty for those who want to heat a small home and still have the capacity to heat a lot of water quickly as needed.
So I'd sit down and think about what features matter to me and then compare the units. Mr. Vitodens is about to get his annual checkup so I'm very interested to see how the HX looks one year after being installed...
@ June 19, 2010 10:49 AM in Metallurgy continued - AL294C Stainless SteelThe question in all these kinds of debates is probably one of cost versus benefit. There is no doubt that Al29-4C is tasty and performs admirably under a variety of conditions - but is it needed when combusting the usual variety of gas-based fuels?
Based on my very limited research, it seems like Al29-4C is of particular use when dealing with very low pH flue gases such as condensing oil (especially when the source fuel is up at or beyond the allowable 1700PPM sulfur limit - may result in a pH at 2 or lower). Under these conditions, crevice corrosion, etc. is a really nasty problem. But in a condensing gas boiler, the pH doesn't drop below 4 (IIRC) and hence the issue is not as pressing.
Most corrosive environments are at their worst when the corrosive medium is allowed to condense/dry on the spot instead of being washed away. In a condensing boiler, it's fairly likely that the condensate will clean the surface semi-continuously, especially in top-down designs like the Prestige and the IBC. In the flue, it's more likely for stuff to dry on the spot after the the boiler shuts down. See how the requirement for Al29-4C vs. 316Ti or 316L varies by fuel and chimney liner manufacturer.
My guess is that going slightly thicker on the HX matieral and/or upgrading to 316Ti is likely cheaper in the context of increasing a boiler HX longevity than switching to a very expensive metallurgy like Al29-4C. Plus, I'd wager that the majority of HX failures out there have something to do with Balance of Plant (BOP) failures, such as clogged sumps, fan disk failures, etc. Thus, it's the BOP where I'd pay the attention, with a special eye on detecting failure modes before they can ruin the HX.
Now, if I was running my boiler on a sour-gas well in my back yard...or a local landfill... oh, I'm not, so I guess I won't worry about that. But if I were to run those kinds of fuel a super-resistant HX might become a requirement.
@ April 7, 2010 8:02 AM in Best tank hot water heaters (gas)... most storage water heaters will not last that long. Replacing a dip tube is an option, but it's perhaps beyond what most homeowners want to do... Consider looking up Larry Weingartens tips on water heater maintenance and repair.
I'd flush the tank a couple of times to see if there is a lot of sediment build up. Dip tubes can fail, usually it's due to age or the water inside the tank getting too hot (at least that's how I managed to do it when I was developing a water heater for a client).
@ April 7, 2010 7:52 AM in Are New Gas Pipes Vulnerable to Lighting Strikes... rather one of the path that the lightning takes once it gets into a home. The cases I have seen (here on the wall) of CSST getting punctured could just as well have been from nails, nicked 220V lines, etc. for all I know. Only an analysis of the puncture areas under a microscope would tell the story for sure.
What I think the underwriters are now trying to address is whether an external lightning/grounding conductor should be required with every CSST install. These conductors tend to be rather thick-gaged wire with few strands for a given nominal wire OD (at least compared to regular flexible wire). It would require more work (i.e. additional fittings) and would hence detract somewhat from the benefits of CSST (of which, fast installs, is one aspect being touted).
The benefit of black pipe is that it's pretty thick stuff. As such, it will be better able to absorb the high powered (and very temporary) arc that lightning generates than a thin-walled CSST pipe section. In a properly grounded home, the gas piping will be tied into all plumbing, electrical, etc. grounds. In our home, the external lightning protection is also tied into all pipes sticking out of the home (gas, oil, water).
Additional failure modes (besides lightning getting into the home itself) could be external piping going to things like gas lamps, outdoor kitchens, etc. Even if your home has lightning protection, not all external components may be covered by the cone of protection. Ditto for some external power connections - they can bring lightning into your home also.
Lastly, there is induced current, a phenomenon whereby a direct hit traveling down an external leader will induce a tremendous induced current in any electrical wiring that is running nearby in a similar direction. That is why having whole-house protection at the breaker panel or lightning protection on the home is not necessarily good enough - electronics need to be protected separately. Really nasty environments will feature metal-walled and -roofed shacks and Ufer foundations to keep the electromagnetics on the outside (i.e. faradays cage + grounding).
@ April 5, 2010 6:44 AM in Millivolt steam system$40-50 a month for gas would be far more than I think a mV system can use. The smallest constant pilots are on the order of 50 BTUs, though mV systems usually use bigger ones. But even at 250 BTU/h, you'd be looking at less than two therms of gas being used per month. In most places, that's less than $5 worth.
I suspect that there are other issues at play. Does this boiler provide just heat or heat and hot water? In particular, is this a boiler with a tankless coil?
Don't get me wrong, there may be very good reasons to switch to a new boiler. In order to make the best decision though, describe your system in greater detail, if possible.
@ April 3, 2010 9:50 PM in Desuperheater - Anyone installed one?... but given our relatively short cooling season, a desuperator isn't going to ave the same benefit up here as in the south, especially with a large condenser HX. Heating the in-home water will most likely be the only result (which is nice) but some of the SEER/EER performance gains that you can see on older systems retrofitted with a desuperator are hence unlikely.
Instead of a external unit (like the aquifier, etc.) I'd opt for a simple refrigerant/glycol HX, put both condensers in series and run the loop with a dedicated pump if either condenser calls for heat. The glycol loop would be teed' off the solar system loop... easy enough. But with some of the other changes I am making around here, I want to see if the added DHW heating bonus of the condenser desuperators actually makes sense.
@ March 30, 2010 7:31 PM in Adding Humidity, Part Deux... just happens to be the highest point in the people's republica of Cantabridgia. But a hill is a hill and wind speeds tend to be higher up here. And now back to the gulag, aka digging out my electrical service.
@ March 30, 2010 7:27 PM in Adding Humidity, Part Deux... the lifebreath 30TRV actually contains a ERV as well as a HRV core. So, I should be good. I like the stirling product, but IIRC it won't fit in the present space. Wall legend Jerry Scharf made me aware of it, alas too late for this project (at least upstairs). Speaking of which, I miss Jerry and hope he is well.
@ March 27, 2010 9:25 AM in Modulating is it efficient?... can we find two Levittown or similar 'identical' homes in which to hang a Monitor MZ and another condensing boiler that also modulates? That's one way.
Another way is to hook up a BTU meter for a home and to compare a MZ-equipped home vs. one with a modulating, condensing boiler. Then compare how many BTUs go into the house vs. fuel use. See what the net difference is. Not too hard to do, a couple of thermowells, one or two flow meters, a WEL or similar data logger.
Going forward, I will be monitoring the fuel usage vs. the HDD in our home. I'm pretty convinced that we'll be saving fuel on account of the much lower standby losses associated with the Vitodens vs. a 30-odd gallon Vitola. I suppose a longer flue may help with allowing some pre-heating, but I think one grasps at straws when the return temperatures are in the mid-80's.
@ March 25, 2010 8:18 PM in surge protector on mod con?Specifically, the two outlet model (http://brickwall.thomasnet.com/viewitems/standard-surge-protectors/two-outlet-surge-protectors?). To this non-EE who dabbles in electronica, the elimination of MOVs seems like a great idea. I had one installed in ME, to protect a APC UPS, which in turn feeds a Vitodens with electrical juice.
Most anything electronic in that house has been zapped, damaged, etc. by the many spikes and sags in the electrical supply, but the Vitodens (and the APC) have been unscathed...
@ March 24, 2010 7:59 AM in Lead Abatement ?While that inspector may give you more trouble in the future for daring to challenge him and/or causing loss of face, it is your right to insist he/she do their job as intended instead of making up interpretations to suit their needs as they go along. Given the quality of work you and your crew do, the added 'heat' shouldn't be the problem!
@ March 23, 2010 7:59 AM in Lead Abatement ?... stripping lead paint from window sashes and pulling out 80-year old
caulk while volunteering for a pre-school house renovation. Everyone
thought I was nuts for wearing a 1/2-face respirator, nitrile gloves,
etc. (I brought my own)- they went for simple N95 masks, no gloves,
We had a talk about lead during lunch on the job site and one volunteer
mentioned a neighbor whose kid got acute lead poisoning on account of
contractors tracking lead dust from parts of the home under
reconstruction into other parts of the home where there were babies
crawling/hoovering the floor. So job-site cleanliness is one factor, as
is occupancy. I'm sure none of the contractors did it intentionally,
they just didn't know better. A good family friend of ours also got
acute lead poisoning from a crumbling porch paint job when she was 2.
Many folk doing exterior and interior paint stripping pay no attention
to where chips go, potentially contaminating a large area, when lead
containment is easy - shop vacs not only contain the stuff so there is
less mess to clean up afterward but also help with sanding by sucking
away anything airborne that could get in the way. Yeah, having to handle
a long hose is not a lot of fun but neither is picking up stray flakes
in the back yard.
Lastly, I see a lot of this lead awareness re: sanding products as a
increasing fear of industry re: falling down the same path as all the
asbestos manufacturers. I.e. everyone and their uncle getting sued
because some product at some time may have contained minute amounts of
asbestos. Hence all the warnings on sandpaper. I'm not sure what the
best answer is re: lead abatement awareness, what would you suggest
instead of mandatory classes?
@ March 23, 2010 6:19 AM in Lead Abatement ?... stripping lead paint from window sashes and pulling out 80-year old caulk while volunteering for a pre-school house renovation. Everyone thought I was nuts for wearing a 1/2-face respirator, nitrile gloves, etc. (I brought my own)- they went for simple N95 masks, no gloves, etc. instead.
We had a talk about lead during lunch on the job site and one volunteer mentioned a neighbor whose kid got acute lead poisoning on account of contractors tracking lead dust from parts of the home under reconstruction into other parts of the home where there were babies crawling/hoovering the floor. So job-site cleanliness is one factor, as is occupancy. I'm sure none of the contractors did it intentionally, they just didn't know better. A good family friend of ours also got acute lead poisoning from a crumbling porch paint job when she was 2.
Many folk doing exterior and interior paint stripping pay no attention to where chips go, potentially contaminating a large area, when lead containment is easy - shop vacs not only contain the stuff so there is less mess to clean up afterward but also help with sanding by sucking away anything airborne that could get in the way. Yeah, having to handle a long hose is not a lot of fun but neither is picking up stray flakes in the back yard.
Lastly, I see a lot of this lead awareness re: sanding products as a increasing fear of industry re: falling down the same path as all the asbestos manufacturers. I.e. everyone and their uncle getting sued because some product at some time may have contained minute amounts of asbestos. Hence all the warnings on sandpaper. I'm not sure what the best answer is re: lead abatement awareness, what would you suggest instead of mandatory classes?
@ March 22, 2010 7:16 AM in Modulating is it efficient?... replacing two 84% AFUE Buderus 124X for one Vitodens 8-32. Besides being 2x over-sized, this supply-house designed system also had endemic issues with air entrapment on the upper floors, a very hot boiler room, and near-boiler piping that made my hair stand up straight. So there were a lot of issues besides swapping a proper boiler in a proper system for a proper condensing/modulating boiler.
But the customer saved 46% on the propane bill (despite rising LP prices that year) without any other changes to use. And, unlike years before, the house now heats very evenly, without noise, etc. Point being, that a 12% difference in AFUE doesn't tell the whole story. It's as good as any indication that there are significant penalties associated with oversizing single-stage systems that by definition will be oversized 97% of the year, even if they were properly sized in the first place! Modulation addresses that major issue (nameplate capacity vs. required input) for much of the year.
A high-mass system may be able to ameliorate some of the issues associated with single-step firing under non-design-day conditions (i.e. limit short cycling) but a better approach is to match the input to the heat loss. That's what modulation allows across a certain range of input capacities. With time, I expect boiler manufacturers to extend the modulation range of their gear to lower and lower input capacities. However, there are diminishing returns, especially for low-mass systems (i.e. less standby loss, less mass to heat, etc.), so it might make sense to cap the lower end of inputs at 15kBTU as most manufacturers do and to design the gear to handle the resultant short cycling during late spring and early fall/winter.
This experience is why I decided to abandon Ms. Vitola (who is almost properly sized) and retrofit a Vitodens, rather than fit a gas burner to Ms. Vitola.
@ March 22, 2010 6:53 AM in Am I Being UnreasonableIIRC, someone here mentioned that HD assesses at minimum a 6% finders fee for the contractor. Presumably, the lucky guy/gal also gets to buy all of his/her supplies at/through HD as well... and once the customer has paid up, all that lovely cash goes into a money market account where it'll sit until HD has to pay the contractor, accruing interest. Since HD is holding all the cash, the contractor is beholden to HD, not the end-customer, sort of like a usual sub-GC relationship, except GCs are usually beholden to their customer (unlike HD, IMO).
That's why it is unlikely that I'll ever hire a HD contractor. At the very least, they have to make up the 6% finders fee by cutting a corner elsewhere, all things being equal.
@ March 20, 2010 10:40 PM in Modulating is it efficient?As a start, I'd look at the different forms of heat transfer out there: radiant, convective, and conductive. A heat exchanger that is optimized for modulating boilers has to manage to scrub the flue gases just as effectively as when the burner is running on full-fire. I believe that is why we see a predominance of heat exchangers with very small openings for the flue gasses to pass through (i.e. a 1mm or less) in the condensing/modulating market. A radiant-dependent HX design wouldn't do as well for multiple input levels, IMO, since the flame luminosity is likely lower at low-fire than at high-fire. Not sure anyone does conductive HX, since that likely leads to CO, and other unwanted byproducts.
So, I would argue that a proper HX combined with modulation should yield higher efficiency (all things equal) in a furnace or a boiler since you're increasing the amount of surface area for a given amount of heat transfer. The charts that Viessmann has published re: Vitodens performance as a function of ΔT and firing rate seem to confirm that trend. However, the trick is for flue gases to have good contact with the HX surfaces, regardless of flue gas speed/rate.
Thus, I'd imagine that a very 'throaty' HX like the tubes typically found in the primary HXs of furnaces don't do as well at low-fire as at high fire since the flue gas flow at low firing rates may be a lot more laminar, thus insulating the hotter flues gases at the center of the tube. At higher firing rates, the turbulence caused by the inducer likely improves the HX performance. So the benefit of the HX surface area vs. required heat transfer may be negated by the lesser turbulence in the tube, leading to consistent AFUE performance across multiple firing rates or perhaps even a decline at low firing rates. IIRC, Steve Ebels once tested a two-step furnace at both firing rates and found consistent AFUEs.
Whether or not the burner has consistent combustion conditions at various input ratings is likely a function of design. IIRC, some current designs either meter the gas as a function of the air, while others meter the two completely independently. IMO, the independent solution is the better (tough likely more expensive) one, since it could allow you to account for changing caloric content in the natural gas, etc. in a way that a fixed ratio does not.
I noted with the many furnaces we just tore down at work that the secondary HX tends in condensing models have much narrower passages, sometimes with the addition of baffles, than in the primary heat exchangers. Perhaps not as sophisticated as some of the boiler heat exchangers, but clearly with the same aim: i.e. narrow passages scrub the flue gases more effectively than wide ones. Yet, on account of the lower modulation range of blower systems in furnaces and the lesser ability of air to transport heat (than water), I doubt that furnaces will offer the same wide range of inputs vs. boiler systems.
@ March 18, 2010 3:01 PM in Is there a reason to prefer Triangle Tube over Lochinvar?Both companies are privately held, so owning stock in one or the other likely isn't it! :-D
But seriously, I suppose the somewhat unique heat exchanger is one reason that someone might like the TT over the Lochinvar.
More importantly, are the boilers a good match for the intended loads? Are the temperatures of the supply and return waters in the right range, etc.?
Let me turn it around: If everything is OK, eco-system-wise, why would you have a big preference for Lochinvar over TT? It seems like you have a preference for one product over the other, so what I would do is present the customer an option:
1) Go with the spec'd system.
2) Install the system you prefer after you convince the customer that it's better
At the end of the day, it's up to the customer and your ability to inform them about their options. Some 'engineered' systems I have seen lack basic knowledge of the products involved... for example, a gas-fired Vitola combined with a LLH. These sorts of problems are especially acute in 'simple' residential-scale applications where some engineers are simply out of their usual field (think large commercial installations/hospitals/schools/etc.) since that's not what they do every day and not what they see done every day.