Heat loss by usage?

Brewbeer

Heat loss calc for my house came in at about 32K, usage estimate is about 24K at a design of 0F. SWT of 130 at design.

Gordy

Key point is having the emitter to absorb the btus. As ME pointed out in his last post. Over emitterization plays a very crucial role.

Tinman

"The poor slobs who use the Manual J approach".

Really???

I think the contractors who you just insulted are the ones who are head and shoulders above the rest.

Garbage in. Garbage out.

Leon82

I have a feeling he was being mildly sarcastic, as I'm sure ME put extra emission purposely.

Rich_49

I won't speak for others but I for one am not offended nor insulted by Hatts comment . We are forced to perform Manual J by most AHJ s and codes .

Here is the problem . Not many understand Equivalent Full Load Hours . While some are all looking at fuel usage they do not take into consideration the house coasting through higher temp days leveraging the heated mass , stretches where you may have record cold and your customer is perceptually freezing his **** off , have fun explaining the science to that cold **** .

Since , as Stephen said , We are head and shoulders above the rest . You should not size a boiler by gas usage since these hills and valleys DO EXIST . I might add that if you take pride in what you do and design , restore , repair , install heating systems you should never get calls from your clients that they are cold , EVER . If yoiu are doing your job the best way possible you should be measuring room by room anyway to determine where your temps and such should be anyway .

Imagine the poor **** that read this and follow the USAGE Guy's advice . They'll use the winter of 15-16 and in 16-17 ,
17-18 their customers will not be pleased . Fuel usage can go very wrong , a room by room and knowledge rarely will .

Rich_49

Leon82 said:

I have a feeling he was being mildly sarcastic, as I'm sure ME put extra emission purposely.

Extra emitter is always a good idea since it will allow for lower water temps for more of the year but still have capability during those peaks .

Tinman

I say put in all the emitters you can... or your wife will allow.

I've been doing quite a bit of work at churches that have peak use once, maybe twice, a week. Usage won't do me any good there. But a room by room loss will insure I never get a called out on my day of rest.

ChrisJ

Rich said:

Imagine the poor **** that read this and follow the USAGE Guy's advice . They'll use the winter of 15-16 and in 16-17 ,
17-18 their customers will not be pleased . Fuel usage can go very wrong , a room by room and knowledge rarely will .

I think it's a skill and an art like anything else.

2015-2016 was a mild winter in our area, you'd have to be a fool to use that to size a heating system.

Now using 2014-2015 on the other hand should yield very good results.

Mark Eatherton

Hatterasguy said:

.

Mark Eatherton said:

My load said 100K, I put in 100K of emitters, but only 50K of heat source. Snug as a bug in a rug, even BELOW design conditions.


ME

Can you reconcile the fact that you were off by more than 50% on the load calculation?

That's a serious error.

If one of the industry's top individuals has a heatloss error of 50%, that doesn't bode well for all the rest of the poor slobs who use the Manual J approach to determine boiler and emitter size.

No miscalculations there Hatt. But thanks for implying...

Load came in at around 95K to 100 K using three different programs. As I said, I would NEVER do what I did in my own home on a customers house, but when I see a customers house having 50% duty cycles, and I did a tightly detailed loss/gain analysis, it tells me something is WAY off (obviously loads don't take real world cases into consideration). My 1953 era home had a 200K furnace before I took it out and replaced it with an 80% EFF water heater. Short cycle city on the GFA unit. I've since replaced my Y2K water heater (no power required, gravity circ potential) and replaced it with a modcon Munchy.

Since getting rid of the forced error heating system, I've reduced my energy consumption by 70%. Utility company came out and gave me a new gas meter for FREE, bless their hearts. When I showed their mechanics the gas meter I have connected to my boiler with the pulse output contacts connected to a PC along with all the other data logging capabilities, they just shook their heads and left. Mumbled something about energy geek on the way to their truck.

The house has undergone significant conservation efforts since it was originally built, but most recent load calcs too that into consideration...

My gut feeling tells me that the infiltration factors we "assume" are in reality, significantly lower than our estimates. I've also been bitten in the butt by infiltration factors that were signficantly higher and uncontrollable as well, which REALLY sucks. Conditions beyond my control and poor craftsmanship on the AC guys part...

The reason I put the load calculated emitters in was so that if it turned out that my gut was wrong, I could easily remedy it by placing a larger wall hung heat source. Ain't gonna happen.

Sometimes, we get too hung up in the numbers, and can't see the forest for the trees. The heating world is not black and white. It is grey.

Your milage may vary...

Speaking of reconciliation, can YOU, or anyone else reconcile why it is that when your home is half way between design condition and neutral that you don't use nearly as much energy as you theoretically should? Or how about when you are AT design or below? Theoretically, for each 1 degree your exposure drops below "design" conditions, the internal temperature should drop 1 degree F. I've NEVER had that happen (with the one exception noted) in my many years of treking through homes at or below design condition. Oh sure, if it STAYS below design condition for an extended period of time, the rooms can cool off, but short journey's do not drag the building down. Thermal mass contribution...

I'd submit that if your home does use exactly as much energy per hour as you'd calculated, you probably have a high infiltration factor that is influencing the numbers. Low and no mass houses have completely different characteristics than mass intensive homes do. That's a natural fact.

BTW, none of this is a secret. I've written numerous article on it over the years. I've calculated the energy content of all the mass located within my home, and there are TONS of mass, conductive mass at that which can contribute to the loads. The number escaped me long ago, but it blew me away at the time.

Forgot to mention, I've never seen my modcon at 100% capacity, even at or below design conditions. Maybe 80%, but never 100. Makes reality suck even more eh...

I've said it before, and will say it again. Our current heat loss "estimates" need reviewed, and revised to take into consideration all the things in real time that affect a given buildings loss. No one wants to get the call that their system is undersized. As Dan has said no less than a million times, "The urge to oversize a heating system is stronger than the urge to have sex".

ME

SWEI

Very similar experiences here -- Rich and Mark both described it well. Ganged mod/cons on commercial projects (and huge houses) ROCK. When properly sized to the heat loss, one third to one half of the heating plant is all that will ever fire, except perhaps during peak DHW demand periods.

In the electrical/electronics world we use the term crest factor, and it represents the peak to average ratio of a signal. Most nights, OAT drops noticeably right around sunrise, often by 5-7°F. Very, very few buildings can't carry a two hour dip. Masonry buildings (even when leaky and quite old) can take DAYS to heat up or cool down significantly. Building mass is completely missing from both the Manual J and ASHRAE/IBR heat loss methodologies. There are sophisticated energy modeling packages that do consider mass, but they require detailed 3D modeling of the structure and envelope that would be cost prohibitive to do for most existing structures.

njtommy

You guys bring up a lot great points.
I've never seen an undersized boiler only over sized. I will completely admit I've done it my self. Not on purpose, but mainly lack of knowledge and understanding.

ChrisJ

njtommy said:

You guys bring up a lot great points.

I've never seen an undersized boiler only over sized. I will completely admit I've done it my self. Not on purpose, but mainly lack of knowledge and understanding.

Yeah.......99% of steamers installed.

Robert O'Brien

Rich said:

I won't speak for others but I for one am not offended nor insulted by Hatts comment . We are forced to perform Manual J by most AHJ s and codes .

Here is the problem . Not many understand Equivalent Full Load Hours . While some are all looking at fuel usage they do not take into consideration the house coasting through higher temp days leveraging the heated mass , stretches where you may have record cold and your customer is perceptually freezing his **** off , have fun explaining the science to that cold **** .

Since , as Stephen said , We are head and shoulders above the rest . You should not size a boiler by gas usage since these hills and valleys DO EXIST . I might add that if you take pride in what you do and design , restore , repair , install heating systems you should never get calls from your clients that they are cold , EVER . If yoiu are doing your job the best way possible you should be measuring room by room anyway to determine where your temps and such should be anyway .

Imagine the poor **** that read this and follow the USAGE Guy's advice . They'll use the winter of 15-16 and in 16-17 ,
17-18 their customers will not be pleased . Fuel usage can go very wrong , a room by room and knowledge rarely will .

You just can't resist the ad hominem attacks! USAGE Guy is an ad hominem attack,as it would be if I were to refer to you as "HTP shill guy" I've asked you nicely to refrain from this,yet you persist? I also suggest you brush up on what is a PM and what isn't.

Rich_49

I was in no way singling you out Robert as opposed to addressing the differences between one method as opposed to another . Several others have advocated for usage also , what would make you think I was specifically talking to Robert ? You are not that important , simmer down and quit pissing in my Cheerios . Have no doubt comrade , if I want to address you it will read @Robert O'Brien

I don't take much offense to HTP Shill guy either , I have the sense to use quality equipment from a manufacturer that gets it and supports their product with integrity .

Have a good day BOB !

Robert O'Brien

"Since , as Stephen said , We are head and shoulders above the rest ."



Modesty is your middle name! Your sense of self importance, arrogance and rudeness are as endless as your humility is non existent! And I still have the taste of Munchkin in my mouth! Good day!!

Rich_49

Hmmm , you have no idea how wrong you are .

Learn the words you are using also , Ad hominem would entail an attack on your person or character , neither of which I have ever done . Can you say the same , Mr . humility , arrogance , self importance ? If Giant Rectum inflamed you so you really are flower .

gennady

I guess most times boiler is working in steady state, house is warm and set. Heat loss by fuel consumption reflects it. Now here is scenario. At design temperature boiler fails at night. Plumber comes in the morning, house starts to freeze up. Plumber fixes the problem, boiler starts.
-It is yearly morning, still dark ( no solar gains)
-most of electrical appliances off,
-no lighting ( no internal gains).
-strong wind ( high infiltrations)
Will boiler be able to pull this house off if boiler is sized based on steady state fuel consumption?
Just asking. Always eager to learn.

Gordy

Radiation density plays a key role in this.

gennady

Or another scenario. 2 identical houses, one next to another. One has properly sized boiler, running on outdoor reset, TRVs. another one has oversized boiler, short cycling, unbalanced system, half of the house is cold, another half has windows wide open. You get the picture. Both need new boiler. Sizing is by fuel usage. Would they get same size boiler?

ChrisJ

Hatterasguy said:

gennady said:

Will boiler be able to pull this house off if boiler is sized based on steady state fuel consumption?
Just asking. Always eager to learn.

You're asking for the boiler to pull off a 40°F climb on the design day with high winds?

I might suggest that any boiler sized exactly to the heatloss via Manual J or via the heatloss via fuel consumption will fail at that endeavor.

Once you're at design, there is precious little margin for winds in most localities. There is certainly no margin to enable a large climb in any reasonable amount of time. The first 20°F will happen relatively quickly.............the second 20°F is going to take forever if it happens at all.

But, like most design days...............they come and they go. Patience is a virtue.

I don't know.

My "undersized" steamer could pull off a 40 degree climb on design day with high winds no problem. In fact, I'd bet it could do it 20 degrees below design day.

Robert O'Brien

gennady said:

Or another scenario. 2 identical houses, one next to another. One has properly sized boiler, running on outdoor reset, TRVs. another one has oversized boiler, short cycling, unbalanced system, half of the house is cold, another half has windows wide open. You get the picture. Both need new boiler. Sizing is by fuel usage. Would they get same size boiler?

Conversely, I ask if you would do a heat loss on one of these homes after already doing them on quite a few others? FYI, they are oil, no gas available. 900 square feet as seen in this pic although they have been added on to in the ensuing 65 years but based on lot size, they can't get very big! And there are 17,000 in just this development.

jonny88

Off topic a bit but I was just on the phone with a heating guy I know.Currently he has 22 Munchkins at 14yrs old and actually put one in his g/f house 7yrs ago.Also 8 Munchkins in Bklyn 7yrs old still running smooth.Install and service is the key.Brought it up as Munchkins were mentioned earlier in the thread

ChrisJ

Hatterasguy said:

ChrisJ said:

My "undersized" steamer could pull off a 40 degree climb on design day with high winds no problem. In fact, I'd bet it could do it 20 degrees below design day.

When we are speaking of "undersized" on a hot water system, we refer to the heatloss as compared to the output of the boiler.

When you are speaking of "undersized" on a steam system, you refer to the standard pickup factor (33%) versus your actual pickup factor and are unconcerned with the heatloss.

Yes,
That's why I said it, because we really should be concerned about heatloss with steam. It actually does matter.

But that's another argument, I'm just hoping Fred won't see it here.

Robert O'Brien

Hatterasguy said:

Robert O'Brien said:

Conversely, I ask if you would do a heat loss on one of these homes after already doing them on quite a few others? FYI, they are oil, no gas available. 900 square feet as seen in this pic although they have been added on to in the ensuing 65 years but based on lot size, they can't get very big! And there are 17,000 in just this development.

Is this a trick question?

Just as much as the question I was responding to!

Robert O'Brien

jonny88 said:

and actually put one in his g/f house 7yrs ago.

And she's still sleeping with him?

Paul48

There's so many things to consider. I don't think there's anything wrong with doing a fuel usage. But, it's not a good idea to use it alone. Use it along with more conventional calculations, and if it doesn't match you need to find out why. Thermal mass, layout of the home, number of occupants, insulation, air infiltration, habits, and expectations all play a part.
If you don't take the time, you WILL let some of your customers down. We've seen it here a thousand times.......a contractor installs a mod/con to replace a bang-bang oil-fired boiler, and the customer continues doing what he/she has always done...turn the temperature back 20* at night. The heating professional failed. There are certainly no one-size fits all boilers, of any kind.

Robert O'Brien

Just here today, one of the 17k Levitt houses. They want the quietest boiler they can get since this in the kitchen. Going to remotely locate an indirect. The quietest boiler that fits is a Firebird condensing oil boiler. Comes in 90k or 120k. Do I need a heat loss to tell me which one to choose? If the heat loss is 25 or 35 or 55 or 65 does it matter? Paraphrasing Hillary there!

Robert O'Brien

Unless they make smaller boilers! The DHW issues can be overcome with a bigger tank and a mixing valve

jonny88

They really are a tough setup.Had a customer recently who wanted his boiler removed from kitchen etc but the price was not in his budget.Gotta see to believe.

ChrisJ

Robert O'Brien said:

Just here today, one of the 17k Levitt houses. They want the quietest boiler they can get since this in the kitchen. Going to remotely locate an indirect. The quietest boiler that fits is a Firebird condensing oil boiler. Comes in 90k or 120k. Do I need a heat loss to tell me which one to choose? If the heat loss is 25 or 35 or 55 or 65 does it matter? Paraphrasing Hillary there!

That's oil fired?
How do you service that!?!?

jonny88

Chrisj they are usually hung in a closet.When they puffback you get some mess.Never enough combustion air etc but all to typical in these homes that were designed at that time .Your joking about servicing right.This is Long Island.Oil companies change filter and nozzle and call it a day.

ChrisJ

jonny88 said:

Chrisj they are usually hung in a closet.When they puffback you get some mess.Never enough combustion air etc but all to typical in these homes that were designed at that time .Your joking about servicing right.This is Long Island.Oil companies change filter and nozzle and call it a day.

The guy I hired back in 2011 didn't even do that much.
That's what triggered me doing all of my own work.

Paul48

I think if I owned one of those houses, my first "addition" would be a boiler room. Were these built for returning GI's from Korea? I wonder if they were originally electric heat.

Robert O'Brien

WW2. They were radiant, copper tubing directly buried in slab. They have almost all been replaced by baseboard.

Rich_49

Rich said:

Hmmm , you have no idea how wrong you are .

Learn the words you are using also , Ad hominem would entail an attack on your person or character , neither of which I have ever done . Can you say the same , Mr . humility , arrogance , self importance ? If Giant Rectum inflamed you so you really are flower .

Robert O'Brien

Rich said:

Rich said:

Hmmm , you have no idea how wrong you are .

Learn the words you are using also , Ad hominem would entail an attack on your person or character , neither of which I have ever done . Can you say the same , Mr . humility , arrogance , self importance ? If Giant Rectum inflamed you so you really are flower .

You're like a dog with a bone, just can't let go! In defending yourself against assertions that you engage in ad hominem attacks, you engage in yet more ad hominem arguments as if that bolsters your position!

Rich_49

http://literarydevices.net/ad-hominem/

Abusive ad hominem usually involves attacking the traits of an opponent as a means to invalidate their argument(s). Equating someone's character with the soundness of their argument is a logical fallacy.

Ad hominem abuse is not to be confused with slander or libel, which employ falsehoods and are not necessarily leveled to undermine otherwise sound stands with character attacks.

Robert O'Brien

Rich said:

http://literarydevices.net/ad-hominem/

Again you confirm my allegations, your comments are the very definition of ad hominem and then you graciously post affirmation!

Rich_49

Robert , this will be my last comment on this issue . I posted the very definition of Ad hominem so anyone who may not know the meaning could see . Please post where I made a personal attack on you or you character on any forum as opposed to enter into a debate with you on the basis of the subject matter at hand .
You sir , attacked my character traits as you see them which I might add could not be farther from the truth . This in no way negated the validity of the points I made in disagreement with HLCs vs Gas usage .
You even stated in the piece you published in Mechanical Hub that you were gonna hear it from many . Guess you really were not as ready to hear it as you thought . The comment you made which precipitated this portion of the storm is based on you seeing something that I wrote Hatteras which I thought was private which referred to you using an unflattering term , big deal . You should have kept it offline as I had intended . You CHOSE to attack my character and insult me in the way of pointing to my lack of understanding of the internet and PMs .
Good thing I am a heating / cooling guy and do not perform IT services .
Maybe you should read all those definitions again and try to comprehend what they actually mean . Take a breath , calm down and be reasonable .

Question , what is one of the first questions we ( includes you) ask folks looking for help whom have had a malfunctioning system installed ? Jeopardy music here .

Robert O'Brien

Since you asked. These are a few examples of ad hominem arguments. Pretty simple concept really!

Rich →
Don't wanna inflame the giant rectum but , He can do his boiler sizing that way but after he does that if he has any inkling to provide a quality product to the end user he will still have to do the room by room and a radiation survey to figure out a reset curve and what temps he can use in his system . So , how much time did this **** save by using the quick and dirty method ? None , unless he has no desire to give the great product .


Rich said:

Hmmm , you have no idea how wrong you are .

Learn the words you are using also , Ad hominem would entail an attack on your person or character , neither of which I have ever done . Can you say the same , Mr . humility , arrogance , self importance ? If Giant Rectum inflamed you so you really are flower .

Rich July 2015
What is lost on you Robert is that you believe you are intelligent