Whats your boiler water temp this morning?

6.4 Degrees Outdoors...

Ms. Vitola is at 134°F (just finished reheating the indirect), the supply to the RFH system is 96°F. ~4.6 Gallons of #2 fired in the first 8 hours of "today" (the WEL does not observe DST changeovers).

8:00 am and 6.6 degrees out side

Indoor reset 1st floor is 68 2nd floor in the mid 70's, with 164 degree water. That's with 3 rooms next to the indoor sensor without heat.

Massachusetts

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Southwest part of Boston

it was an even zero this AM, about 5:45. My Monitor MZ was 140*. House was trying to catch up (66 heading to 68 which it should have reached at 5:00 ("Legal" outdoor design by code is 7*).

May be time to re-set the curve? Eh- I am doing just fine.

Smiling in comfort

With an Ulta80,, 6am this morn was 4 degF,,, 140 kept me good at 70 in the 3 beds zone, but a little lacking in the kitch/liv zone [home is 1325 sq with 88 ft fintube]

Bumped water temp up to 150f, but more importantly, bumped back gas input to 32K btuh max and still able to overshoot tstat.. looks like the sweet spot

At 8am...

Thanks for the surprise quizz! ;-)

OAT 4

BST 134

BRT 126

IAT 72+

but what is the design water temp?

test

25°F outside.

92°F supply temp.

94°F flue temp.

81°F return temp.

Boiler kicked out of modulation at about 10:40 a.m. with an outside temp of about 40°F. Clear night and very sunny day.

Brilliant, Jack

What do you mean you're no Einstein?

You are meeting setpoint with a perfect 10 degree delta-T, you probably have room for more output (you definitely do) and you have a happy client.

Einstein, on the other hand, has been gone for 52 years and has his brain in a jar somwhere in Princeton.

So...which would you rather have for yourself?

You rock.

Had to head out to work @ 5:30 this morning and ran downstairs to check also. (Glad to see I'm not the only crazy one out there!)

My GB was rockin @ 134 degrees, the house was holding strong @ 70 & it was 10 degrees outside. God I love radiant!!!!!!!!

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

Mine

Buderus G115
Taco PC 705 injection controller was maintaining boiler temp @ 149 F, mix temp was holding around 137 F feeding my cast iron base. That was when I left for the first call of the day at 5:30 AM with a outside temp of 7 F and the house not moving from 72 F, Johnstown Pa.

Supply 212F Return 212F Duh!

There is more to life than numbers and how hot water compares to steam, but I don't know any better.

To expand a bit on BC's numbers, he was at 212F for 7.5 hours, while the rest of the time the steam was flat. Stone cold radiators. (Note how this is drastically different from what hot water is - Most have posted water temperatures of above 100F, which in constant circulation, will have presumably been kept that hot all day long)

While steam comes at 212F, this is not the average system supply temperature; oppositely, hot water supply temperatures are (within a bracket) the average values. Can we compare apples to oranges? Yes we can.

BC's system ran for 7.5 hours. In his whole day, there were yet another 16.5 hours that ran cold, and steam goes cold and flat within minutes (this is a source of great efficiencies). We can now compute the average system temperature for BC's system, let's guess his home is at 68F (radiators under draughty windows would be colder yet).

(212F * 7.5h + 68F * 16.5h) / 24h = 113F weighted average

113F averaged supply temperature for steam is surprisingly low considering BC lives somewhere where it was only 6F. In comparison, Al also at 6F, reported 128F. (Technically, this 128 is more of an instantaneous morning number, and I'd expect the average supply temperature for the whole day to be lower, possibly 113, who knows)

Steam heat grabs you by the lapel, gets you out of bed in the morning and shakes you until you're cooked. You feel the heat and it's addictive. At 113F, it certainly isn't crazy at all, just different.

What is modulated in a temperature space in a modern hot water reset is equally modulated in a time field for hot air and especially hot steam. Same difference.

Was this a good splash or what?

Friday AM

Since I'm nuts like everyone else here, I take a look every morning.


6 AM

Monitor MZ

9 Degrees OT

160 water temp

72 inside

Thats the highest the temperature has been in at least 2 years. And their was heat to spare. Maybe I'll turn it down a little. Just for kicks.

Weezbo-

I have a 40 degree zone in my house too, but I call it "my refrigerator"

So, you heat your refrigerator with radiant to keep the milk from freezing?

I have to imagine at -24 and you let the dog out, you had better check to make sure he is not frozen to the hydrant

Some years ago the weather forcaster on a local radio station stated that in parts of NE that night, "the mercury would drop to 40 below..."

Naturally, I called up to take exception because mercury freezes at about 38 below.... He managed to get out the word "smart@ss!" before slamming down the phone in my ear.

I guess cold makes people grouchy

Mr Egli

(212F * 7.5h + 68F * 16.5h) / 24h = 113F weighted average

So the boiler starts at 68° and returns to 68° within seconds after the heat call ends? Amazing!!! ;-)

9 outside

it was 9 degrees yesterday morn when i was leaving home ,my munchkin t80 was running at about 135 keeping my home at 69 with all slant fin 30 and some staple up radiant (4 -180 loops onixon)Yet to get a gas bill yet since i put the new boiler and have been home but last months was about 40 bucks less with the house staying at 68 and the indirect maintaning temp but no one was home .Low water temps rule .peace and good luck clammy

Good man! If I could turn this house 90 degrees I would, but I can't. The real bummer is that the neigbors trees, over 90 feet high, keep me in the shade. Solar only works for a couple of hours. When I craok some one is going to get a really well insulated house though!

Oh, I leave for a day, and I'm already missed

Building a full head of steam makes my head swell to unbelievable dimensions. Thanks Brad for making it no longer fit through the doorway... Thanks for the heartfelt word.

Now, for some bubble busting... The system fluid in a steam heated place does not go from 212F to 68F in mere minutes... I lied... I exaggerated... it all happens within seconds. Seconds. (of which there can only be as many as 60 in a minute)

Here is how it works.

Let's talk about a one pipe system with vents at the radiators - just because it is easier to visualize, but it's the same in any steam system. Turn it on.

We have the boiler putting out a cloud of steam, which, like the storm front on the weather channel, it advances and retreats on the mere whims of the jet stream, el Nino or even the command of a global thermostat.

In home heating, this cloud advances only within the confined boundaries of our cast iron radiators. The cloud, or more technically the space occupied by the cloud, is our heating medium and it comes in only two very specific configurations. Nothing in between.

The cloud of condensing steam is very obviously at 212F, and although steam particles within it travel at about sixty gazillion miles per hour, the cloud itself only lumbers down the pipes at a rushed pace. Stop the heat, and the cloud shrinks in the opposite direction at about the same rushed pace.

What replaces the cloud when it collapses out of the way? You know exactly how this happens: the vent reopens and re-supplies the pipe innards with atmospheric air taken at room temperature, at thus 68F. The radiator retreat, which only lasts the time of one pace leaves behind it an emptiness filled with cold air. The heating fluid which comes in the shape of the moving cloud goes from 212F to 68F in mere instants.

Try it out at home. Boil yourself a cup of tea while playing with the kettle. Full flame - full steam plume. Turn the gas fire off and the whistling stops on the spot. Steam goes away in seconds, there is no waiting for inertia. The concept is so powerful, there is (or used to be) a commercial that emphasizes a quick acting cold relief medicine by flaunting a steaming tea kettle. Flu - gone like the wheezing plume - quick - as seen on TV.

Of course the next post will claim that the cast iron itself, of which the system components are made of, will not change temperature while we stare impatiently at the watch. That's true. But heating and cooling goes both ways and whatever time it takes to warm up - gets returned upon cooling. More or less the same delay and whatever it is, it's not a concern for studying internal fluid temperatures of either water or steam systems. 7.5 hours of steam shortened by 10 minutes of warm up time and lengthened by 10 minutes of cooling time is still 7.5 hours. Baffling.

Fluid temperature is all we were concerned about in this thread. Hot water in one case, a hot and cold cloudy space sometimes filled with steam in this particular case.

Interestingly and surprisingly, the average supply temperatures are the same for steam or hot water leaving us with no sledge hammer argument to go convert the world.

Pshhh.

I've got more... can I go on a bit?

The race to the coldest fluid temperature is held as the holy grail of efficiency, but is it? [In thermodynamics book stuff only the opposite is true]

If it truly were the key to system wide heating efficiency, then the most boring forced air furnace should always win out - it does suck in air at the lower ranges of indoor temperature; this is far colder than any returning water can ever dream of; the same mostly holds true for supply side temperature. Steam does not play this game.

So, this is the question now: Do we know forced air systems to be by default always more efficient than a hydronic one? If low temp water is, when compared to steam, then it must be further true that lower temp air is too, in comparison to water.

Cough cough, I need some of that cold therapy I was advertising earlier.

The cold source temperature argument holds true in one fashion. Greater heating efficiency and economy is gained by lowering the indoor thermostat to the lowest lower possible low setting. Weezbo's 40F indoor relative to -27F in Alaska seems very balmy indeed.

Bob

I think your point makes sense in part and particularly when a system settles to equilibrium. It is definitely part of the equation, no doubt! More emitter to heat loss and the lower the temperature as you know well.

Most of these posts are based on outdoor reset as you can imagine, so the marvelling is about how close the boiler is producing supply temperatures which are tracking design intent.

The other part is, some systems such as the Vitodens, jump off the programmed curve apparently, favoring longer burn times at lower input to still meet setpoint.


Can anyone imagine a time in history when low water supply temperatures confer bragging rights?

I love this age!

Chris

My roof is oriented east and west too, but I built my collector array over a deck. I also had the same problem with my neighbors tree, but they let me cut it down when I told them what I wanted to do. Bob Gagnon

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"