More Boiler Porn
This is my new boiler installation, which I posted a while ago on my reno blog (south slope reno) but since everyone is loving these photos, why not do it again? Since now we have some experience running it. This is a Lochinvar Knight KB150 modulating condensing boiler, with an indirect water heater (TurboMax). This…
This is my new boiler installation, which I posted a while ago on my reno blog (south slope reno) but since everyone is loving these photos, why not do it again? Since now we have some experience running it.
This is a Lochinvar Knight KB150 modulating condensing boiler, with an indirect water heater (TurboMax). This is supposed to be one of the most energy-efficient configurations available. The boiler is over 95% efficient and qualifies for Federal and Keyspan energy rebates. It’s hydronic baseboard, but is supposed to be even more efficient at radiant heat.
It’s set up with four zones.
One zone is for the entire first floor; LR, bath, kitchen, DR.
One zone is for the second floor minus the guest bedroom, i.e., MBR, master bath, and office.
A third zone is set up for the guest BR so we can keep that low when it is not in use.
The fourth (unused) zone will be used for the basement when we get it to be somewhat more finished.
Naturally each zone is controlled by a programmable thermostat set to our needs.
We had agreed to do some of the pipe insulation and my wife discovered she likes it, so we got a little carried away with that part of the job.
We’re going to get some of the control wiring a bit more protected next week (the blue cable at right is a network cable that fed my computer when it was in the basement and is not part of the installation).
The intake goes thru the wall (the house is semi-detached) and the exhaust is run thru PVC up to the roof, using the old chimney as a chase to hold it.
There has been a steep learning curve on this boiler for all concerned, and we have had one visit from the factory rep, plus a few from the installer. It took me a couple of weeks to notice that we were getting numerous temperature overshoot and high limit errors.
The factory rep as well as the installer discovered a couple of silly things; the return sensor was cable-tied to the pipe. When my wife insulated over it the sensor was dislodged. So we solved that by putting it in a well. The second thing was that the outdoor temp sensor was giving faulty readings because when the cable was run along the ceiling, one of the installers managed to put a staple thru it!
At the same time, this boiler is designed to run and to do ‘soft lockouts’ so it will provide heat and hot water even if there are considerable errors such as we had here. The downside of this is that if you don’t pay close attention you won’t notice the problems until you get your gas bill! And December to January was almost as high as the old Weil-McClain steam boiler we had before we started renovations.
After we corrected these problems, and made some programming changes, our bill for Jan/Feb (one month) was $280, and that was including one week when the boiler was still not running correctly. So I’m hoping to get a gas bill of around $200 for this month (and that includes that Wolf stove, lol).
One thing I learned is that these boilers are just big computers. There are dozens of variables that can be programmed in, and installers don’t know all of them, and even the factory rep that was here left the boiler not ramping up quickly enough.
While my installer didn’t want to hear this (same as the AC guy), since he claims mis-programming by homeowners causes him huge problems, it behooves the savvy homeowner to carefully RTFM and learn what each programming option means and experiment as necessary (but never change more than one option at a time so you can roll it back if the results are unexpected).
Meanwhile the circulating pump for the guest bedroom failed (sounds like a bearing failure), so we’re just leaving the door open so the GBR picks up enough heat from the rest of the floor. That’s no one’s fault, of course, and a new pump will be installed next week.
We’re ripping the 1968 sheetrock off the basement ceiling to try and get rid of the dust and debris that is underneath from the renovation, then we can really clean up the boiler.
While I generally agree with you, MP, in this case, even with my cynicism quotient turned up, I have to defer to Fine Homebuilding. I doubt they would suggest an unsafe installation…I posted the “open system” noting that FH said it was controversial, meaning that the danger of bacteria is well known, but not everyone agrees. I have no opinion on that issue, but:
“Heating boilers differ from domestic water heaters in that they are designed to sustain higher internal temperatures indefinitely while employing redundant safety devices to protect the occupants in the event of things like runaway flame, low water, carbon monoxide spillage, overheating, electrical failure, etc. An overwhelming majority of water heaters don’t do that. They are big dumb tea kettles for the most part with a single gas-regulating control of limited accuracy”
But the point is, that the w/h can run at 125F instead of “sustained higher…temp”; as Polaris and others are both well-established brands and have a reasonably long track record, I cannot agree that they are “less safe” as heating sources than boilers. For one thing, they don’t go low water so there’s no need of a probe (I’m sure they have a catastrophic empty turn-off.)
I might eat crow if you could cite non-trivial figures as to actual damage/fires caused by w/hs.
As to capacity, Polaris has a 199kbtu unit, more than enough for the typical brownstone.
On your other, moral, point on efficiency, I agree fully; but, at the same time, green as I try to be, ROI does play a part in my replacement strategy (otoh, I have steam, which gives me an easy out since there ain’t no he steam units.)
you sound convincing. I will get new boiler this spring and replace pipes in basement. I will not put 95% (since it is overkill IMHO). But something like 85-90% gas furnace.
Sorry if I offended anybody.
People, don’t take this personally. Rather, take it from where it’s coming:
I love reading people’s justifications for being cheap by claiming smart.
Frequently, posts on this forum seem to laud the virtues of doing things the wrong, cheap and non-compliant way. Often those virtues are limited to the money saved.
Here is no exception.
In our part of the country we use boilers because we have winters like the one we’re experiencing this year.
Our dwellings are connected and we live next to and on top each other.
In many other parts of the country, the stupid stuff that people do affects only them and their families. Here, what we do affects many other innocent people just trying to live their lives.
So…
We have a code that dictates the use of fuel burning appliances that are engineered for safety and efficiency.
Heating boilers differ from domestic water heaters in that they are designed to sustain higher internal temperatures indefinitely while employing redundant safety devices to protect the occupants in the event of things like runaway flame, low water, carbon monoxide spillage, overheating, electrical failure, etc.
An overwhelming majority of water heaters don’t do that. They are big dumb tea kettles for the most part with a single gas-regulating control of limited accuracy.
And the idea of using an open system to make heat and hot water is ridiculous in this day and age. The previous poster is right to site the growth of legionella as a major concern.
Ask the cruise ship industry.
It takes a lot of BTUs to heat a house and controlling and distributing that amount of energy safely, effectively and efficiently takes a boiler that is designed to do that task.
Water heaters are far less costly because they’re designed to do a less-demanding task.
And Denton is right.
Didn’t we all love All Gore’s movie and after watching it get pissed off at people who routinely don’t do the right thing?
In Europe, most countries have official Boiler Inspectors that make annual inspections in every home to measure efficiency. Europeans know that a home-heating boiler lasts 10-15 years before it drops below an acceptable level of efficiency. Then they get a new one and start burning less fuel again. Should we blame Europe for global warming by citing their boiler-filled landfills (boilers are over 90% recyclable) or embrace their commitment to efficiency?
bob, sometimes it’s just about doing the right thing, even if the economics aren’t completely favorable. Plus no one knows what the price for natural gas will be down the road. But I need to point out that the 35k was for a whole system, not just a boiler. THis was a complete gut reno and the price covers the tubing and rads and so on for an entire house. To look at your comparison, I’d have to know what the cost was for the boiler alone, and I don’t.
non to make a lot of fuss, but how it that a “high efficiency”, if you spent 35K on installation?
I have original 1910 boiler for hot water. I feel it will work for next 20 years (the effective life of your boiler). Mine is 60% efficient your is 95%. So we get 1/3 difference in oil cost. It amounts to ~1000$/year. Which is 20K for 20 years. So I will actually save money by keeping what I got 🙂
As for the “CO2 footprint, etc”, you should not forget that any way you spend money in oil consumption. In my case it burns oil. In your case there is burning involved in melting copper and building device and then you pay for installation and the installer will use your money to fill up his truck and drive around. I seriously do not see much difference.
Well except you will get back 30% of govt. money… my tax money… Wait a second, the only way to get even with you is to install the same thing. 🙂
i’m a little fuzzy on this, but if chise says 127F, water heaters can produce that for hydronic. So if FH is right, you can save a lot on your next boiler replacement.
Capacity may be an issue; the Polaris is 100kbtu, you’d need more for a 4-story brownstone (typically 150-180kbtu). The article was probably for smaller houses where 100kbtu was enough.
How interesting! We have the same boiler albeit the 80,000 BTUH wall hung model and the Superstor Ultra. When I have time, I will post pics. Just had it installed last year. Awaiting the Keyspan rebates. No Federal rebates for 2008 installations 🙁
We have only one zone (our rads are pretty well balanced in terms of size compared to heat loss) and we retained the cast iron rads due to their high mass which actually works really well with low temp systems like these.
Denton is right. Read the manual. Our installer had set the set point (the highest temp the boiler water reaches) at 180F which made the boiler short cycle (keep switching on and off). I set it at 127F and it has stayed there all winter. The rads never get too hot, but they emit a pleasant gentle heat and the house warms up pretty quickly too. The great thing about this boiler is how little the room temp fluctuates. We spent about 13.5K for our setup (we did not rip out the rads and piping in the house) which vents out the back of the house.
the thing is, and please correct me if i’m wrong here, if you want to use a water heater instead of a boiler then you have to significantly reduce your heating load first and probably have radiant underfloor installed instead of the more common baseboard. so costs might be far higher to actually do this because you will have to re-insulate your house more and you would likely have to tear up your floors to retrofit pex tubing for radiant. i don’t think hw heaters can reliably provide sustained temps high enough for baseboard in most brooklyn houses. also if you use an open direct system then you might get condensation (mold) in the summertime and also you have use higher cost pex (for potable water because you will be drinking the water that runs through your floor heating system) and also worry about possible bacteria that can cause Legionnaires Disease.
Fine Homebuilding 3/09, page42-47.
Cost comparisons: gas he Veissman boiler installed cost=$14/sqft; Polaris (American W/H) or Phoenix (Heat Transfer Products) w/h $4/sqft. Supposedly this use has a 20-year track record.
More radically, one installer uses open-direct system (no heat exchanger for water to radiant system) which is not up to code in many places, further reducing costs.