# Yet another boiler room - very simple



## futz (Sep 17, 2009)

This one is very basic. All radiant. Standard gas-fired tank.

Anyone else bring a table to work? I always do for bigger jobs. Much easier on the back than bending over for everything. Just a half-sheet of 3/4" ply and some cheap folding legs from the builder's supply.








I used Hugin to stitch two pics together for this panorama. You can see some imperfections across the middle.
















The two 45's are because I ran out of 90's just then.


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## user2090 (Sep 26, 2009)

That looks like some good work. Makes me want to do more boiler work. I haven't had one since a year ago. Keep up the pics. I like to use some kind of table when I am going to be on a job for more than a day.


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## jeffreyplumber (Dec 7, 2009)

looks good!


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## SPH (Nov 4, 2008)

Looks good! But why the gas fired water heater? why not an indirect storage tank?


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## futz (Sep 17, 2009)

SPH said:


> Looks good! But why the gas fired water heater? why not an indirect storage tank?


As always - budget.


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## ILPlumber (Jun 17, 2008)

Looks pretty clean. I am going to haev unistrut drop shipped to ya though:laughing:


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## Miguel (Aug 10, 2009)

Nice looking job, futz! Very clean and efficient piping.

Is that boiler only 40mbtu?
Looks like primary/secondary injection loop. My fave these days, even if circulators were twice the price it's the way to go IMHO.

At first I thought you had a tempering valve on the DHW but at closer look it's a vac. break? Is that a Conbraco?

When you say radiant, do you mean rads or in-floor? Looks like radiators but hard to tell without the complete picture.

Kudos!


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## futz (Sep 17, 2009)

Miguel said:


> Is that boiler only 40mbtu?


What makes you think that? It's a 203NC - 62mbtu, I believe. By old fashioned standards that's a ridiculously small boiler for that size of house. But these days it's how we size them. On the coldest day of the year (not all that cold here at the coast) that boiler should run 24/7 flat out. Makes it much more efficient on all the mostly milder days of the heating season.



> Looks like primary/secondary injection loop. My fave these days, even if circulators were twice the price it's the way to go IMHO.


It's primary/secondary, but not _exactly_ injection. It has a mixing valve way at the back, feeding off a pair of close-spaced tees coming off the boiler loop.



> At first I thought you had a tempering valve on the DHW but at closer look it's a vac. break? Is that a Conbraco?


Up on top there? That's a Watts N36.

Or do you mean that funky Conbraco thermal expansion ball valve? We're required to put either one of those or an expansion tank these days. I hate em.



> When you say radiant, do you mean rads or in-floor? Looks like radiators but hard to tell without the complete picture.


When I say "radiant" I always mean in-floor radiant. I'll always call radiators "baseboard". I try to stay away from baseboard these days anyway. It's a lot of work, largely because I refuse to use PEX for them. I still pipe baseboards in M copper.

Running PEX for baseboards means the pipe is running right at the extreme top of its temperature range. What happens when an aquastat goes out of calibration with age? They ALWAYS stretch, meaning the temp goes up - not down - so then you're beyond (possibly WAY beyond) the pipe's rated temp range. If the loop limit aquastat happens to fail at the same time then you might have a bunch of burst joints in ceilings. Maybe I worry too much...


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## OldSchool (Jan 30, 2010)

futz you should try using Spirovent air eliminator on your primary it works a lot better to get the air out of the system. Also we use Wirsbo rated at 180 Deg at 200 PSI, about the best Pex on the market


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## futz (Sep 17, 2009)

OldSchool said:


> futz you should try using Spirovent air eliminator on your primary it works a lot better to get the air out of the system. Also we use Wirsbo rated at 180 Deg at 200 PSI, about the best Pex on the market


I don't have air problems at all. After a rough purge, my systems self-purge from there. Good design, a simple cast iron air scoop and a few strategically placed air vents do a very good job at minimal cost.

Spirovents are very good, but an unnecessary expense on the systems I build (hundreds of dollars as opposed to a $15 air scoop). I would definitely include one on a high-end system or on a large commercial system (along with a pot-feeder and other niceties (valves under AAVs )).

I've used Wirsbo. Got the whole Wirsbo sales pitch and used it for one big job (the boss loved the pitch  - that was before I became self-employed). I'm sure it's good pipe but... meh. Sales pitches don't do much for me.  The other brands are good too. I've had good results with whatever brand I use.


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## Scott K (Oct 12, 2008)

*A few points*

Personally I'm not a fan of air scoops even though they were the standard not too long ago, but a few suggestions:

It is commonly recommended to leave a good section of straight pipe upstream of an air scoop. They don't like turbulent water (where as as spirovent or other air seperator you want this turbulence from the 90). They generally perform better this way. 

Another suggestion. When you come out of the boiler and then 90 into the scoop - put a tee where that 90 is and put then put a hose bib on the top. Then put a valve between this tee and the air scoop. Since you are filling through your scoop i.e. the point of no pressure change with the fill valve and Expansion tank connection, this is the absolute best place to purge the system. You can manually open up zone valves and purge the zones as well as boiler accordingly. If you have a manual away to turn on the circulators, even better. 

I also noticed there didn't seem to be much straight pipe between your air scoop and your primary pump. Again one of the little things that can make a difference in the longetivity of the pump - I've heard 6x to 12x the pipe diameter or more for recommendations on the length of this pipe between the air scoop or air seperator and the primary pump. One of those little things anyways. 

Remember that there are 3 types of air presnt in heating systems and spriovents eliminate 99+% of them. An Air scoop can not. 

Also, I'm curious about what pipe sizes you are using. Typical flow rates require 2 to 4 feet per second, and in your system with a 20 degree delta T you're looking at either 3/4" or 1" as the pipe size range you could get away with. If it's a 62,000 BTUH input, that's in the 50,000 BTUH range you would only need 3/4" pipe for the mains. For 2-4 feet per second flow rates you need 3.2 to 6.5 GPM with 3/4" type M.

Also, difficult to see, but how much isolation is there for servicing? I guess maybe it's "not in the budget" but if you had to shut this system down to replace something, I guess they'll have to repurge the entire system where their savings for a few extra valves will not be realized? 

The biggest problem in the heating trade is there are no real standards. Even the Teca standards seem to be lacking. There are no provisions or codes for the degree of isolation. I could get a guy with 3 quotes, the first guy would be bare bones, no valves for isolation, basic flanges, etc, the next guy might valve the crap out of it allowing excellent isolation for servicing which could save the homeowner big $$$ for servicing down the road. Yet the cheap guy might always win?


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## futz (Sep 17, 2009)

Scott K said:


> It is commonly recommended to leave a good section of straight pipe upstream of an air scoop. They don't like turbulent water (where as as spirovent or other air seperator you want this turbulence from the 90). They generally perform better this way.


It would be real nice to have enough room to do that, but it never happens. It gets maybe a 3" nipple upstream if it's lucky. They always work fine. 



> Another suggestion. When you come out of the boiler and then 90 into the scoop - put a tee where that 90 is and put then put a hose bib on the top. Then put a valve between this tee and the air scoop. Since you are filling through your scoop i.e. the point of no pressure change with the fill valve and Expansion tank connection, this is the absolute best place to purge the system.


I *totally* disagree. Purging upstream of a pump is an exercise in futility. The air just keeps coming and coming and coming (I think it sneaks in past the purge valve o-ring  ). (The air scoop is an exception because I don't have to babysit it for hours - it works on its own). I always put my purge valves on the return lines (I put some coin vents on the return side of upstairs loop manifolds for making rough-purge easy) and let the pumps push the air through to them. 

EDIT: Read your post more carefully and I see I missed your suggestion of an extra valve in there. But then you're trying to purge with incoming water. I've never had any luck with that. Doesn't work. I need the pumps on (high speed) and circulating to get the air out. Your valve prevents that, and it takes up more space that I don't have.

EDIT2: Actually, I was just thinking... Your design is one of the two optional locations given on the boiler layouts. I build mine (same thing as yours, only reversed) in the downstream-of-the-pump location, rather than upstream. But I virtually never use the valve - only the boiler drain (sediment faucet/hose bibb). Anyway, most of the air comes out other places than the boiler loop.

You're in Coquitlam, so you're probably working off the same diagrams as me. We're really not so far apart in design methods, I think.



> I also noticed there didn't seem to be much straight pipe between your air scoop and your primary pump. Again one of the little things that can make a difference in the longevity of the pump - I've heard 6x to 12x the pipe diameter or more for recommendations on the length of this pipe between the air scoop or air separator and the primary pump. One of those little things anyways.


Again, there just isn't room in 99% of boiler rooms. I haven't found it to be a problem anyway. They last just fine. Taco's are ****e anyway - I never expect long life from them.  Wear the piece of crap out and replace it with a decent Grundfos.



> Also, I'm curious about what pipe sizes you are using. Typical flow rates require 2 to 4 feet per second, and in your system with a 20 degree delta T you're looking at either 3/4" or 1" as the pipe size range you could get away with. If it's a 62,000 BTUH input, that's in the 50,000 BTUH range you would only need 3/4" pipe for the mains. For 2-4 feet per second flow rates you need 3.2 to 6.5 GPM with 3/4" type M.


Boiler loop is almost always 1-1/4" (or whatever size the boiler in/outlets are). Most typical radiant feed/returns are 1", but I upsize to 1-1/4" from the pump to the zone valves to make things easier. My supplier does the piping layout for me as part of the heat loss calculation package (it's required here). They give me a layout diagram with what type & size mixer/diverter valve, minimum pipe sizes, pump model #'s, speeds, etc.



> Also, difficult to see, but how much isolation is there for servicing? I guess maybe it's "not in the budget" but if you had to shut this system down to replace something, I guess they'll have to repurge the entire system where their savings for a few extra valves will not be realized?


Isolation is good - not perfect, but good enough to make service reasonably easy. Making it perfect would add substantial cost, and just more parts to fail. 

Full repurge would not be required to replace boiler air vent or boiler loop (primary) pump. 

Upstairs radiant partial repurge might be required for radiant pump change, but boiler repurge would not be necessary. 

Radiant zone valve manifold air vent could be easily "glugged" (drop pressure & have new one doped and ready - change it fast - loop water isn't hot enough to burn ya) to avoid repurging loops. 

On a baseboard manifold you might have to repurge a bit (tho you can glug it if it isn't too hot), but usually you can blast small amounts of air right through the rads without it sticking (I ream everything - makes em purge out easy).

If it's a hybrid baseboard/radiant system then each can be serviced without getting air in the other. If there's an indirect tank then that can be isolated off and repurged by itself too.



> The biggest problem in the heating trade is there are no real standards. Even the Teca standards seem to be lacking. There are no provisions or codes for the degree of isolation. I could get a guy with 3 quotes, the first guy would be bare bones, no valves for isolation, basic flanges, etc, the next guy might valve the crap out of it allowing excellent isolation for servicing which could save the homeowner big $$$ for servicing down the road. Yet the cheap guy might always win?


We do have standards here. They're not perfect, but I have to follow that diagram fairly closely - the inspector has a copy when he inspects the heating system. Isolation valves ARE on the diagram. The latest designs in the newest book are damn good - they're easy to adjust and service, and they age well (very important).

Before they brought this inspection system in, heating systems were all over the map. Some were crap, some were overkill - anything went. I like it better this way.


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