Heating Help

Aye, that it may be....

@ April 12, 2011 4:27 PM in Second Opinion on Radiator

If cobbled in, it must have been 40 years or more ago, my guess. Vintage pneumatics. But you probably are right.

Check out

@ April 11, 2011 9:49 PM in Second Opinion on Radiator

that relatively small branch feed and control valve size. Looks like 1/2" pipe- rare to see it that small. Reminds me of Gerry Gill's Iron Fireman system, but this one may have been a vapor or vacuum system. May be one of those rare gems.

Housekeeping Pads

@ April 11, 2011 9:41 PM in question about poured boiler bases

To me they are the sign of a first class job and are an industry standard in commercial work. But in that category, they are reinforced and doweled to the main slab, sometimes an entirely different pour and foundation where vibration is an issue such as concert halls and libraries.

I do not consider them flood protection, heck if you have 4 inches of water, you may be ok but a foot and you have other issues.

But to make the job competitive, use solid patio blocks set down in a bed of hydraulic cement or thin cement grout to bond with the base slab. Then form and place the concrete around and atop those. This will save volume (try to get one bag to do it), and the patio blocks form a bit of an anchor. A good concrete mix without too much tooling will give you a nice, level surface. Use an edger for a neat finish, sets you apart.

OK, go ahead. Sign your name :)

Spiffy and Inspiring

@ April 10, 2011 8:34 PM in Thanks,Dan!

What a happy bunch of folks and neat workmanship to be proud of.
Nice shade of red there, too!
Kudos all around and to Dan, the sine qua non of so many things.

Good engineering, John

@ April 9, 2011 10:05 AM in Scary water heater replaced by Lochinvar 98% thermal efficiency unit.

Congratulations on having the foresight (and guts, sometimes, frankly), to assess the true demand and sizing accordingly.

I was impressed with the Lochinvar factory, engineering and manufacturing, including the QA/QC procedures. Very much state of the art, as good as any in Europe I have seen. Lochinvar engineers tend to "think like the user" and their controls and applications reflect that.

Now you will show them the value of storage in such a system. We know that on-demand systems bring along constant cycle losses for each hand-washing and that hot water through-put is the dominant energy variable. But now their production costs I would expect to be noticeably lower. I hesitate to put a number on it, but we all have a number in the back of our heads.

All that and another neat installation worthy of your last ones, as always.

If I were to use

@ April 9, 2011 9:54 AM in "Pool Noodle" as pipe insulation

pool noodles as pipe insulation, I would only use them on hot water. I do not trust that 220F rating for a finished product. 

Yes, a solid block of PE might have that rating (I really do not know), but I can almost guarantee that no one tested the pool noodle for a condition so far outside of its actual use.

Yes, I do prefer my hot tub on the warm side, but if a pool noodle melts at a certain temperature, it may have a market on CannibalCookery.com as a way to say, "Done!"

I would stick with rated products installed according to their listing and seek color elsewhere. :)

Condensing

@ April 9, 2011 9:44 AM in condensing or non condensing

What a condensing boiler produces as liquid waste is essentially water but with dissolved carbonic acid from the combustion process. There are also trace metals from the boiler and from minerals in the gas itself. Iron, zinc, chromium, things like that.

Natural gas, when burned as perfectly as possible, yields carbon dioxide and water vapor.

When burned imperfectly, carbon monoxide and nitrous compounds are produced. All combustion produces in reality some carbon monoxide, but efficient systems produce very little when operating properly.  Some aldehyde products are produced, partially from the ethyl mercaptan odorant mixed in with the gas. Cannot be helped.

The nitrous compounds are produced as a function of the air supplied for combustion.

All combustion needs from the air is oxygen, which at sea level comprises about 21 percent of air. 78 percent of air at sea level is nitrogen, going along for the ride and doing nothing for you. Too high a temperature and the nitrogen combines with excess oxygen to produce oxides of nitrogen (NOx) but nothing recreational, dammit.

So in a non-condensing boiler, what goes up the chimney tends to have higher CO (carbon monoxide), more nitrogen compounds, water vapor (not condensed!), carbon dioxide, some aldehyde compounds. But the water vapor, well vaporized and not condensing until it hits the dew point (we hope in the open air and not before), is the dominant difference.

Super Fly in the Ointment

@ April 6, 2011 9:13 AM in rad too high

You bring up a very good point Bob.  I should have elaborated to check the pipe movement first by disconnecting the radiator and pushing or pulling to see if the riser moves freely. You are entirely correct, one hard turn against a joist and there is little one can do.

On the other hand, I have disconnected radiators (for other reasons, not shortening the riser), and the riser dropped a few inches with a thump! That would be a satisfying condition to have here.

But the point remains, test the movement first.  Thanks for pointing that out!

That reminds me

@ April 6, 2011 8:24 AM in rad too high

you may be able to find salvaged or even newly manufactured iron "stacking cups" (I call them). These cones of iron (not to be confused with "Buns of Steel"), have top recesses to fit the leg support points and spread them out over a wider base. They raise the radiators in 1-inch or 1.5 inch increments, the few that I have seen.

An old-time plumbing supply house may have these or check on-line.

Most

@ April 6, 2011 8:21 AM in rad too high

risers that I have seen (not that I have seen all nor as many as most installers on this board, but I have seen a fair number), are not supported for one or two stories.  Any clamping or binding would not benefit the self-supporting nature.

Everything has exceptions, but given the rigidity of iron pipe and the old-timer's appreciation for pipe expansion, I would be willing to bet that the pipe risers were allowed to "float". Any clamping would hinder the expansion process and require other means to absorb the movement.

That is my $0.02 anyway!

It would not be the first time

@ April 5, 2011 9:57 PM in rad too high

but if the riser is straight (I take it that this is a second floor radiator), you could do the lowering in the basement where you have better access (or greater tolerance to make a small mess). 

In other words, cut the riser base and lower it down all at once. You can shorten a string from either end, after all.

No matter what you do, you may be cutting and threading in place, but plan carefully to keep that at a minimum. Do not change the pitch while you are at this. I hope this is clear and makes sense.

Window Longevity

@ April 5, 2011 3:41 PM in district heat vs. using an on-site boiler

Good analogy. At the risk of going off-topic, you are correct, a typical replacement window (the good Low-E glass types), indeed have payback periods in decades, 40 is not uncommon. (The window you are replacing may not be perfect but is doing something...).

Moreover, the window folks talk about this being a 20-year window as if it is a good thing, notwithstanding the fact that the window being replaced is OK after 120 years of service.

But a good steam boiler? I would expect 30 years median life, but to get there, one has to monitor your feed water to keep ahead of leaks. Fresh water is the enemy and you have to measure it to manage it.

As Charlie said

@ April 5, 2011 10:30 AM in Tankless Coil

it depends on the usage. The inefficiency come in when you keep the boiler hot all the time on the off-chance that you want to wash a plate or your face. If not kept hot, you will have to wait.

Boilers in general and steam boilers in particular get really upset when asked to write, "what I did on my summer vacation" essays.

If you already have a tankless heater, you can improve it by installing a, well, a tank! A made for the application insulated stainless tank or electric water heater as an approved vessel. This tank would be connected to the tankless coil with a bronze circulator to "charge the tank". You would draw off this tank allowing small usage without firing the boiler and a buffer volume to allow the boiler to fire, then rest.

Without this tank, your boiler will fire with every gallon you draw.

Hey John!

@ April 5, 2011 9:30 AM in Buffer Tanks

One year warranty?? I did not know that. Too bad. I wonder why that might be, so will ask HTP.

I think instead of specifying a time-based warranty, I will just ask that the warranty be longer than one of Charlie Sheen's tantrums. :)

Thanks, John- you got me thinking as usual.

Sorta like what Mark said,

@ April 4, 2011 10:25 PM in Radiant over precast

spraying the underside of the deck with foam to capture the mass makes sense, but watch the edges! Truly, if you forget the edges, your losses will increase and your fuel with it. I would go for at least a perimeter of 2" XPS and carry that across on top of the slab, an insulation bathtub if you will.

Bubble foil is not a recommended product. Great entertainment for bored kids that is about it.

Terms and Therms

@ April 4, 2011 10:18 PM in district heat vs. using an on-site boiler

Every time I come across a utility comparison, the terms used vary, Dekatherm, MMTherm... sort of like expressing velocity in Furlongs per Fortnight.

But if I understand your local rate structure at $5.78 per 1 million BTU's input, that sounds like a very good rate. Is it a total rate or are there service and delivery charges added to that? Still good at $0.578 per therm.

The steam at $21.00 per thousand lbs. That will yield 960,000 usable BTUs.

To get the same usable BTUs out of gas at, say, 80% efficiency, you would have to burn 1.2 Dekatherms. At $5.78 per, that will run you $6.93 versus $21.00.  One-third of the cost, if I am grasping this correctly. Steam will be 100% efficient for our purposes. You use it all and probably, maybe dump the condensate. They might take it back, some utilities do. But call it 100% efficient.

Now, of course you still have to maintain the boiler, heck you have yet to BUY the boiler at this point.  But things like the traps, piping, insulation, all of that is common no matter what the fuel source.

We do not discuss contractor pricing here, but if you know the cost of installing the new boiler, we can get you to some semblance of an ROI figure.

Let's say the church has a heat loss of 500,000 BTUH on the coldest day and you have 6000 Heating Degree Days, have 80% boiler efficiency on gas. And let's say you keep it at 70 when it is 0 degrees outside. OK for Pittsburgh.

To heat that annually will cost about $4,460 at your gas cost. (7,715 therms per year.)
To heat that annually with steam will cost about $13,500 (643 Mlbs.)
Basically, gas will cost you about $9040 less per year than steam at that rate. That tells me that a boiler, properly done to assure longevity, will be a better deal. You have a factor of three there, if I understand your rate structure correctly.

I would

@ April 4, 2011 9:47 PM in Quick Informal Survey - Indirect DHW or Not

call it an indirect, as defined by having no combustion, relying on an outside heating source. The volume would not matter. Even a BPX as an instantaneous heater would qualify as an indirect, at least by my definition.

My $0.02 anyway.

What Roland Said

@ April 4, 2011 5:53 PM in Question Regarding Floor Insulation

Is entirely and demonstrably true. I have seen as many leaks "in the middle of a house", connecting basements to attics and even reaching out to above a porch connection.

One blower door test I did on a remarkably tight 1925 house (tight for the age and compared to what I see around here), with a huge air leaking chase behind the stove. The draft, under blower door conditions, moved newspaper on the floor. The air was being pulled down from the attic. Now, normally, that air would go in and up -you would never feel that because air leaving is not blowing across your person for the most part unless you are right next to it.

That one leak, when re-tested, proved to be about 25-30 percent of the home's leakage area, in one place. The attic top was capped with sheet metal and filled with fire retardant foam over mineral wool and caulked. It took an hour or so and probably saved the owner about $200 per year, probably more. The comfort improvement is immediate.

Perception

@ April 4, 2011 2:05 PM in Question Regarding Floor Insulation

The way I use the terms "perception" and "perceived" equals, "as experienced" and in no way says that what is experienced is not real or in any one's head. It is all used to describe valid observations by whatever senses are affected.

Believe me, I have no doubt the spaces are colder! I mean, when my company designs a radiantly cooled floor, the principles are the same as what you are getting for free (and not desired either!).

Because the floor is cooler, yes, it will absorb heat from your spaces, starting with your body in the room. (You are the proverbial tree falling in the forest. If you are not in the room, would you be uncomfortable? :) But the drain on heating energy will indeed affect space temperature and your thermometer and thermostat will pick up on that.

But the air leakage aspects are faster acting. A one air change per hour loss by air exchange speaks more than exchanging heat from radiation to surfaces then conducting these to the outside.

Properly done, a blower door test absolutely can identify where the leaks are. The primary output of a blower door test is a series of metrics such as your air changes per hour at 50 Pascals ("ACH50") your CFM airflow rate, (also at 50 Pascals, the most common benchmark pressure). The specific leakage ratio, your C factor (air leakage in CFM per Pascal differential), etc. etc. That is the easy and practically automatic part. I also get a reading on how large is the cumulative "hole" in your house, the sum of all leaks, rolled into one hole. A typical single family house might have 200 to 350 square inches of leakage area believe it or not. Picture a 30 inch wide window open between 6 inches and a foot, every hour of the day.

What I do when performing a blower door test is allow at least an hour of "leak hunting time". I set the blower in cruise control, holding a fixed pressure, usually 30 Pascals. Then I go around with the owner and, room by room, open and close doors to see which rooms tend to contribute more leakage both measured and felt by the hand.  The use of hand sanitizer is ideal as it amplifies the draft feeling on your hands.

For example, I start with all interior doors closed. I open one room and let the fan stabilize then record the CFM reading at that pressure as well as feel how drafty the room is with the door open a crack -subjective but necessary.  Then I close the door, move on to the next and the next, throughout the house. Certain rooms stand out that when open, the CFM rate increases beyond proportion.

So, I do follow a base protocol which is accepted almost universally (so your results can be compared to someone in Canada, Argentina or Australia with ease), but also identify the locations, often by feel. And no not forget the daylight test- shut off the lights on a sunny day in your basement and look for where the light leaks in. Can amaze yourself.

Radiant Cooling and Air Infiltration

@ April 4, 2011 12:37 PM in Question Regarding Floor Insulation

Whenever you have a surface colder than the ambient air and especially cooler than your bare skin temperature, you are likely to feel cold.

A room with a 60F floor temperature where the room air temperature is 68F, is no different than when we try to deliberately cool a space using radiant cooling in the floor. A few degrees difference and the perception is cemented.

As Steamhead noted, insulation is the obvious and practical way to reduce (not eliminate but reduce), this temperature difference.

Another prime reason for feeling cold when all else seems to have been done or considered, is air infiltration, air leakage. On lower floors this tends to be higher in a house with more than one story, due to the stack effect. Sealing rim joists, edges of floors where they meet walls, electrical outlets (way down the list but easy to mitigate), all contribute to draft reduction. A blower door test arranged through your local utility or energy auditor may reveal things you have never considered before.

But air seal first. (Insulation sometimes, often in fact, prevents effective air sealing, which is the first step to a proper energy upgrade).

Sounds like

@ April 3, 2011 5:37 PM in MANIFOLDS RADIANT HEAT

you thought it out pretty well already.

This is obviously no small job you have here!  Sixteen manifolds?? At 60 mbh the building does not sound all that big and might be over-controlled, just asking. If the house has a heat load of 25 BTUH per SF, that is one manifold for every 150 SF. Even the dog will have one and so will the cat. Or do you mean 16 circuits?

As for manifold brands, I am not familiar with the two names you mentioned. May be good, may not be, I just do not know. Never heard of them.

My concern with odd brands is getting replacement parts and the quality of the metallurgy. For example, some brass, notably from overseas, has been known to dezincify, leaving a crumbling mass of demi-copper. Basically it is a breakdown of the alloy due to stray currents and other oxidizing factors.  So stainless to me is "safer". Brand names too, where you can get new hardware, replacement meters, valves, etc. Short money in the long run and a minor part of the cost.

Could you use copper manifolds and valves? Sure of course. Your tube layout wants each circuit to be within 10 percent of each other and I would also pipe them reverse-return (supply manifold fed from the left, return fed from the right, for example), to even out imbalance potential. The flow meters are nice when you want to fine-tune imbalanced circuits but also when you commission the entire system. If accurate, the sum of flow rates speaks to pump output. But a purchased manifold, with purge valves, isolation, temperature gauges, master isolation and drain valves, to me saves time and time is money. Even copper manifolds will have you making up an assembly.

You mentioned end switches to activate circulators. I do not know the type of flooring you have, the mass of the building and the overall control strategy, but radiant floors, even the lower mass ones, are much slower to respond than a baseboard or air system. Even low mass floors from a cold start might take half an hour to come to temperature. High mass floors could take a day or more. I can only suggest you re-think that, go with slab sensors and room sensors, constant flow and vary the temperature based on a departure from setpoint. More money on controls but the comfort is superior and constant without a wait. Circulator control puts an on-off mode in what is otherwise a modulating mode. Spikes over gentle waves. You want gentle waves.

You can also

@ April 3, 2011 1:44 PM in Buffer Tanks

combine the buffer tank with a hydronic separator, such as a Boiler Buddy. A large tank with large taps to do double-duty.

I think what you are finding is that make-up air units and unit heaters, being low mass and with rapid transfer (moving air) require a relatively constant flow of water. With low mass boilers, this can lead to short-cycling when demands are sudden/immediate, so having a hydronic piggy-bank makes sense. That is, if I gather your application correctly.