Another NTI

[rich pickering]

Just finished this one.
http://www.imagewiz.net/images/hvac/190981_sandy_016.jpg

[rob10]

Nice work.

[Collin]

Not bad for a prairie boy.:D

[Jultzya]

Nice job.

But, please tell me you have a support for that expansion tank. (other than the copper pipe)

I get the radiant floor zones, but where does the one go that's going up?
(to second story?, indirect water tank?)

How do you like that boiler?

[thero]

I'm a warm air guy, but I don't feel very comfortable with plastic tude for radiant applications.

It seems that every time a pertroleum product derivative
is used in for heat transfer or venting, or just being in contact with heat in general, the product fails by cracking or breaking open.

Now before I get my bottom kicked by the hydronic guys, hear me out.

Remember Ultra vent for side wall venting of forced air gas furnace?

It was touted as a life time product. It was plastic and supposed to withstand up to 575 deg. far.
It crumbled after short term exposure to exaust fumes.
Big recall, cost millions for the Ultra Vent mfg.(GENERAL ELETRIC PLASTICS).

Plastic humidifier water tubing. Same problem. If it came in contact with the hot supply plenum or trunk it crumbled, and I don't mean melt. It would crumble and
water sprayed all over.


Some of my hydronic friends informed me of failures of similar nature when the first infloor plastic tubing was introduced in our area.

As a reult they were all turned off by the idea and stick to copper.

I can feel the forth coming barrage of disagreement building.

This is just my opinion, but I am sticking to it.

[Jultzya]

Thero,

How's plastic used for radiant any different then using plastic CPVC for your potable hot water lines
(shower, dishwasher, sink, clothes washer)

Every appliance in the industry uses plastic in it for the water control or for water delivery.

This tubing has been used for many, many years overseas, and has proven to withstand the harsh environments you speak of.

I use it, and I'm not a bit worried.

[thero]

Originally posted by jultzya
Thero,

How's plastic used for radiant any different then using plastic CPVC for your potable hot water lines
(shower, dishwasher, sink, clothes washer)

Every appliance in the industry uses plastic in it for the water control or for water delivery.

This tubing has been used for many, many years overseas, and has proven to withstand the harsh environments you speak of.

I use it, and I'm not a bit worried.


Well for onte thing aal the lumbing I have seen is copper.

Pvc or cpvc is not allowed around here for potable water.

And I admit I am a warm air guy, but I think that a boiler
will cause an extended degree of hi-temp (boiler design temp that is) exposure to petro products than a washer or water heater would.

A boiler has to maintain water temp and would cycle much longer and more frequently that any other houshold appliance.

I called all my hydronic acquaintences and they all told me they would rather run copper instead of plastic tube.

My one friend said, and I am quoting now, "Hydronic plastic tubing is just something that you see showcased
on home improvement shows. And the reason is usually because the manufacturer of the tubing is a sponsor who is contributing a lion's share of the tv show's budget."

As far as the stuff being used so sucessfully overseas, well, I have cousins in three major European countries and they stopped using it because of leaks.

Ironically, they blame the US manufacturers for hypeing the stuff beyond it's realistic cabalities.

[Jultzya]

We use CPVC for water lines all the time.
It holds up very well when installed properly.

Till the radiant tubing proves to be a mistake I'll use it too.

I have seen no trouble out of it.

And as far as leaks.......there's guys here that can't install a boiler with blk pipe, and keep them from leaking.
(there's good installers that do things right, then we have the other, wannabees)

[thero]

Originally posted by thero

Originally posted by jultzya
Thero,

How's plastic used for radiant any different then using plastic CPVC for your potable hot water lines
(shower, dishwasher, sink, clothes washer)

Every appliance in the industry uses plastic in it for the water control or for water delivery.

This tubing has been used for many, many years overseas, and has proven to withstand the harsh environments you speak of.

I use it, and I'm not a bit worried.


Well for onte thing aal the lumbing I have seen is copper.

Pvc or cpvc is not allowed around here for potable water.

And I admit I am a warm air guy, but I think that a boiler
will cause an extended degree of hi-temp (boiler design temp that is) exposure to petro products than a washer or water heater would.

A boiler has to maintain water temp and would cycle much longer and more frequently that any other houshold appliance.

I called all my hydronic acquaintences and they all told me they would rather run copper instead of plastic tube.

My one friend said, and I am quoting now, "Hydronic plastic tubing is just something that you see showcased
on home improvement shows. And the reason is usually because the manufacturer of the tubing is a sponsor who is contributing a lion's share of the tv show's budget."

As far as the stuff being used so sucessfully overseas, well, I have cousins in three major European countries and they stopped using it because of leaks.

Ironically, they blame the US manufacturers for hypeing the stuff beyond it's realistic cabalities.


I wish i could get a spell checker to work here.

[Collin]

Do you think copper would last in a cement slab?
I'm sorry Thero, but it seems your hydronic friends are not familiar with in-floor heating.
No offense.

[tinman]

thats a nifty setup. I like how you kept the zone valve wiring streamline.

[Collin]

Sparky's work compliments yours nicely.

[Jultzya]

Originally posted by Collin
Do you think copper would last in a cement slab?
I'm sorry Thero, but it seems your hydronic friends are not familiar with in-floor heating.
No offense.

Our local LP gas company won't let us run copper through a concrete foundation for this same reason, unless it's sleeved.

[rich pickering]

Jultzya;no support on the tank yet, and I may not add one. There is no weight or vibration there.I did the initial start up without a tank and my pressure only went up 1 pound.Jury is still out on the boiler.

Thero;you have good reason to be sceptical.poly b pipe was and still is one big headache. When used in plumbing systems, the main problem was the fittings. They were breaking but the tube was still good.And any plastic or rubber tubing used for infloor HAS to have an oxygen barrier or you will end up with corrosion on any and all iron components.This is wirsbo heating pex. You can kink the pipe and then restore it by heating it.Also comes with a warranty against leaks.I'm just a dumb plumber, but I would use it in my own house.The NTI is a condensing boiler and the temps going out will max out at about 110f.The biggest complaint that most plumbers have is that you have to work real hard to make pex look good.

Collin and Tinman;I can't take credit for the wiring. The GC is also an electrician and he builds as if he is going to live there.(he usually does)The mechanical room is about 12'x20'.One thing about the prairies, I don't have to work in attics:)

[thero]

Originally posted by rich pickering
Jultzya;no support on the tank yet, and I may not add one. There is no weight or vibration there.I did the initial start up without a tank and my pressure only went up 1 pound.Jury is still out on the boiler.

Thero;you have good reason to be sceptical.poly b pipe was and still is one big headache. When used in plumbing systems, the main problem was the fittings. They were breaking but the tube was still good.And any plastic or rubber tubing used for infloor HAS to have an oxygen barrier or you will end up with corrosion on any and all iron components.This is wirsbo heating pex. You can kink the pipe and then restore it by heating it.Also comes with a warranty against leaks.I'm just a dumb plumber, but I would use it in my own house.The NTI is a condensing boiler and the temps going out will max out at about 110f.The biggest complaint that most plumbers have is that you have to work real hard to make pex look good.

Collin and Tinman;I can't take credit for the wiring. The GC is also an electrician and he builds as if he is going to live there.(he usually does)The mechanical room is about 12'x20'.One thing about the prairies, I don't have to work in attics:)

Deare Rich,

Hope I didn't come off sounding like I was putting down your craftsmanship.

It is a lot more work to put in a boiler and the water circuits than to just do a relacement furnace.

And I sure don't think you are a "dumb plumber".

I just haveseen no clear evidence that would convince that plastic tube is the way to go. Just seen too many petro products fail when in contact with heat.

You say that is a condensing boiler? SWEEEETTT!

You took godd care of those customers with gas as high as it is.

I did not know they made 90% efficient boilers.

Is 110f the design water temp or is that the flue discharge temp, (that question shows I am most defineatly a warm air guy).
Seems a little low for boiler water. But again, it's a
90%er so you are loading more buts per gal circulated.

Allow me to digress a moment, were you ever stationed in 'Nam or Germany in the '70s?
I once knew a man who has your name. Just wondering.

Any way, its a bang up job you did. When I get a camera I'll try to post some of my work and then all those interested can pile on.

See 'ya.
Thero

[rich pickering]

Thero, no offence taken.The combustion rating is closer to 94%.The design water temp is less than 90f,but people like to feel a warm floor.And the flu gas temp is probably about 100f.When I do the combustion check, I'll post the numbers. Gas is our cheapest fuel,unless you want to burn coal.
I'm a Canuck, never been overseas.Get a camera, we need someone new to pick on:)

[thero]

Originally posted by rich pickering
Thero, no offence taken.The combustion rating is closer to 94%.The design water temp is less than 90f,but people like to feel a warm floor.And the flu gas temp is probably about 100f.When I do the combustion check, I'll post the numbers. Gas is our cheapest fuel,unless you want to burn coal.
I'm a Canuck, never been overseas.Get a camera, we need someone new to pick on:)

I spend all my money at casino Windsor in Ontario.

If the ministry of finance gives me back some of waht I lost I can buy a camera, but until they do,
Blame Canada. (Sorry couldn't resist the South Park joke,)

[pdr]

This looks great Richard. I have a few questions though.

Is the boiler/heating system set up for constant circulation?

If yes, is the boiler being run off of oudoor reset, does it have a modulating gas vavle?

Are those honeywell motorized zone valves on the supply?

And is a lwco code in your area for residential applications, or is this a commercial job?

Just a few questions, i have installed quite a few Viessmann Vito-Dens boilers that look similar to this boiler.

Nice work!

[rich pickering]

pdr;The zone valves are eirie pop-tops with end switches. On a call for heat the end switches turn on the boiler. The boiler control turns on the pump and then the burner. The setpoint is controlled by outdoor reset and the burner modulates to control the supply temp. It is a honeywell valve that is made in europe. The boiler control changes the speed of the combustion fan and the gas valve follows by sensing the air pressure.It can also turn on a second pump and go to a second setpoint if there is an indirect WH connected.
Because our boiler inspectors never looked at residential boilers, our gas code was amended with a new section dedicated to boilers.It says that if any part of the heating system is below the boiler a lwco must be installed. And if the boiler has a minimum return temp requirement, a thermometer must be installed on the return.
This boiler is not even in the same league as the Viessmann.

[pdr]

Thanks for the information Richard.

[pdr]

I guess looks can be decieving :)

[pitman22c]

Are you sure you'll always maintain 6 gpm through the boiler this way? It makes me a tad nervous to run these boilers with other than primary secondary piping?

[blackearth]

I'd install a delta p bypass to avoid having to use another pump. Would be relatively easy to install one in that system and avoid doing a lot of plumbing.

[pitman22c]

Originally posted by blackearth
I'd install a delta p bypass to avoid having to use another pump. Would be relatively easy to install one in that system and avoid doing a lot of plumbing.

Okay, that's a new one on me. How would you install a pressure bypass to make sure you have the minimum required flow rate through the boiler yet enough flow to the space heating and indirect W/H?

Please keep it simple as we've never used a deltaP bypass.

[blackearth]

It's essentially primary/secondary but the pump is sized to supply the needs of the boiler with enough head left over to feed the system. This works only with smaller systems as the flow rate quickly exceeds that possible through the heat exchanger. I have done this only on Vitodens 200 boilers which have separate taps for the domestic tank. I dont know much about the Trinity boilers. They apparently do not have separate taps for domestic water heating. In that case primary-secondary is the only way i can see to plumb it and provide domestic priority easily.

[pitman22c]

Originally posted by blackearth
It's essentially primary/secondary but the pump is sized to supply the needs of the boiler with enough head left over to feed the system. This works only with smaller systems as the flow rate quickly exceeds that possible through the heat exchanger. I have done this only on Vitodens 200 boilers which have separate taps for the domestic tank. I dont know much about the Trinity boilers. They apparently do not have separate taps for domestic water heating. In that case primary-secondary is the only way i can see to plumb it and provide domestic priority easily.

We've considered using a higher head pump but the boiler has 7' head at 6pm plus another 6' head for the W/H means a big darned pump. And then if you have a single space heating zone calling the velocity is out of sight. So we just install pumps on both the primary and secondary loops. I was hoping to learn a new trick here. :) Thanks for the response.

[rich pickering]

I'm not sure that primary/secondary is a good option on the NTI.You need 6 gpm with a temp difference to keep it running constantly. If your load can't accept the btu's from the boiler it will still cycle even with a primary loop. A buffer tank would probably help.Keep in mind primary/secondary is usually used with a high temp boiler and differing temp loads.The NTI is a condensing boiler that wants as low a return temp as possible.
If there is a setpoint demand, the supply temp will go to a predetermined setpoint.It will then turn on a second pump and turn off the first pump.All you need is a check valve to keep high temp water out of the low temp zone.

[blackearth]

You need primary/secondary for hydraulic decoupling. The boiler pump will run constantly, but the burner shouldnt. Some of the boilers I have worked with have a diff pressure bypass built into them to allow direct piping, but will allow circulation even if all of the zone valves are closed. Primary/secondary on a conventional cast iron boiler is used to protect the boiler from return temps that are too low. To achieve differing temperatures for the boiler and the system you have to either use a mixing valve or an injection control, such as a Tekmar 356 or 363/364.

As I have said I'm not completely familiar with the NTI boilers. Does this boiler have an end switch? I assume outdoor reset is built into it. Is there a built in diff pressure bypass? The website isnt very specific about the design that I can find. If primary/secondary piping, such as Viessmann's low loss header, is used how does the Trinity control the system temp? Is there a system supply sensor you can strap on the supply pipe? Maybe I just need to get some Trinity technical literature hehe.

After more thought, my earlier post referring to the use of a delta p bypass as essentially primary/secondary wasnt quite right. More like primary with a bypass allowing the pump to run continuously if all the zones are closed allowing for use of a large enough pump to run the boiler and the system in one as long as the flow rates required are possible. If you have the before mentioned 6 GPM and 12 ft head loss, you could use a 26-64 Grundfos and have approx 10 ft left for the system which is approx equivalent to having a couple of 15-42's with primary/secondary. Using the dpb and larger pump will allow colder return temps to the boiler also.

Time change and I can't sleep late................

[rich pickering]

What you have to remember is that the NTI is a condensing boiler. You want to have low return temps.Using it to supply temps above 140 drops it's rating to that of a conventional boiler.
The control is similar to a Tekmar, but the Tekmars are more user friendly.
End switch on the zone valves give the NTI a call for heat.It turns on the system pump and then the burner which modulates the supply temp based on outdoor reset.As long as there is enough flow in a zone, the burner will run constantly.No need for primary/secondary because it can handle low return temps,but a buffer tank would probably be good addition.There is only 15 gallons in this system, but it still works.It also has DHW priority to setpoint.

[Edited by rich pickering on 10-26-2003 at 01:05 PM]

[pitman22c]

Originally posted by rich pickering
No need for primary/secondary because it can handle low return temps,but a buffer tank would probably be good addition.

[Edited by rich pickering on 10-26-2003 at 01:05 PM]

I don't think the point of primary/secondary piping with this boiler is to keep return temp up but rather to assure adequate flow through the boiler at all times.

As a side point using the outside sensor seems to keep the supply temp down. I don't have any data to back this up. Just our observations when we ran a boiler w/o an OD sensor and then w/the sensor.

[pdr]

So when you disconnected the outdoor sensor, did the control go to a default temp. ie 32*f like the tekmar does? that way if your sensor failed the control would supply the heating system with the temp that corisponds with 32*f outside. If it does do something like that, that is probably why you saw a higher water temp with the sensor disconnected, than with it connected.

I am just trying to understand how the NTI works.

[pitman22c]

Originally posted by pdr
So when you disconnected the outdoor sensor, did the control go to a default temp. ie 32*f like the tekmar does? that way if your sensor failed the control would supply the heating system with the temp that corisponds with 32*f outside. If it does do something like that, that is probably why you saw a higher water temp with the sensor disconnected, than with it connected.

I am just trying to understand how the NTI works.

This was several months ago but from what I recall it went to whatever the high limit was set at rather than modulating the temp downward.

[Jultzya]

Originally posted by rich pickering
No need for primary/secondary because it can handle low return temps

NTI instructions state differently:

Quote: "The Trinity boiler is to be used only in a Primary / Secondary pumping system. This is to
avoid cycling problems in systems that have poor flow, or heating zones with very small
capacities. The primary loop system must be used in all cases, regardless of the
configuration of the secondary system design."

They also state that the boilers have to maintain a minimum flow cap:

T150 = 6 gal at a max delta T 45
T200 = 8 gal at a max delta T 45

Their instructions are very specific on the way to install these boilers.

[rich pickering]

Wonderful.I just checked at nythermal.com. Guess what. As of May of this year, they decided that they needed to change their instruction manual.And the NTI that we bought in August didn't have the new instructions.:mad:


HOWEVER, in this particular application, it works.:)

I still think that a buffer tank and primary/secondary would be the best option with a low volume, low temp system.

[rich pickering]

I still don't see how a primary/secondary system will prevent cycling if a small zone is calling for heat.Primary/secondary allows for different teperature zones from the same heat source.It doesn't magically consume btu's.If you only need 10,000 btu's and the boiler produces 50,000 at low fire, it will cycle.

If you don't have enogh flow it will cycle on high limit.
If you cycle on operating limit or on high limit you won't achieve the advertised rating and savings.

We are supposed to be having a seminar on the NTI soon. Am I going to have fun with the rep.


Somedays Grandpa's coal fired boiler looks good:D

[rich pickering]

Near the begining of this thread, I said the jury was still out on this boiler.Wanna guess which way I'm leaning?

[blackearth]

The delta P bypass I was speaking about earlier would keep the flow through the boiler up at all times even when only one small zone was calling for heat. What didnt go through the zones would bypass and still go through the boiler. The burner may turn on and off but the pump will run constantly.