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  1. BrownianHeatingTech

    BrownianHeatingTech Minister of Fire

    Joined:
    Oct 5, 2007
    Messages:
    1,253
    Loc:
    Northwood, NH
    Figured I'd post some photos of a recent install. The wood boiler is a certain green-colored model that I no longer sell. The gas (LP) boiler is an NTI Trinity Ti150C.

    The wall that this is mounted on was formerly a sliding door in the walkout basement. Since there were two, and this one had a damaged pane, the owner removed the door, allowing the wood boiler to be delivered, then constructed the wall which the piping and gas boiler were hung on.

    Not pictured is the air handler, off to the left, which replaced the existing 20-year-old gas furnace. Also not pictured is the A/C condenser, outside. There is also a second air handler in an another attached building, which is where the pex pipes go.

    The two green Taco boxes in the first picture interface the zones and boilers. The larger is a zone-valve-control which interfaces the thermostats with the zone valves, and the zone pump. The smaller is a single-zone switching relay which controls the wood boiler pump. The small black box on top of the ZVC is a simple relay which isolates the Trinity's 5-volt controls from the Taco 24-volt controls. It also has a second set of contacts which the owner can wire to a lamp in the house - when the Trinity is being used for a heat demand (meaning the wood boiler is not, the lamp would light, telling the owner that the wood boiler needs more wood.

    The small white box over the Trinity is an equipment interface module for the Honeywell IAQ thermostat. The thermostat controls heating, cooling, humidification, dehumidification, and can also control fresh-air ventilation, if needed (for modern, "tight" construction). The wall-mounted thermostat is connected to the EIM by only three wires, and they communicate serially. The EIM has ten wires in this system connecting it to the various components (heat signal to the ZVC, hum, dehum, two stages of cooling, and two extras which could be used for a vent in the future). Not having to snake ten wires through the wall makes life much easier. The EIM also has an outdoor sensor, allowing the thermostat to display outdoor temp, and allowing it to modify the humidification operation as the temperature changes, preventing window frosting.

    In the third (DSC01361) picture, the piping is easier to see. The top-left pump sends water to the zones. The small black boxes to the extreme left of that (hard to see, in this picture) are the zone valves, which control where the water goes. The pump immediately next to the Trinity serves it, and the lower pump serves the wood boiler. The black cylinder in the top-center is a hydraulic separator. It prevents the cycling of the zone pump from interfering with the boiler pumps. It also includes an air separator and a sediment separator, in the same unit.

    The second (DSC01360) picture shows the piping from a different angle, and the zone valve at the top-left is easier to see in this one. The large flat object at the lower-left is the flat plate heat exchanger which separates the wood boiler (10PSI water pressure) from the gas boiler (20PSI water pressure). The two pressures required two separate feed valves and two expansion tanks (green cylinders).

    The plywood on the wall in the lower-left (with the dark shadow on it) used to support an old Aquastar tankless water heater, which has been replaced by the Trinity's domestic water system (internal to the boiler case).

    Joe Brown
    Brownian Heating Technology
    www.brownianheating.com

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  2. Eric Johnson

    Eric Johnson Mod Emeritus

    Joined:
    Nov 18, 2005
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    Loc:
    Central NYS
    I love looking at installation photos. Nice looking work.

    Why did you pipe the expansion tank with black iron? Mine is piped the same way and I've never understood why not copper, since everything else is. I didn't see a way to isolate the tank until I looked at the bottom photo. The second valve was hidden behind the pump capacitor housing.

    I see Greenwood doesn't give you a tapping for the pressure relief valve on the boiler, either. Same deal with the EKO. Any idea why that is? Most conventional boilers that I've seen have one welded right into the top or side of the pressure vessel.
  3. BrownianHeatingTech

    BrownianHeatingTech Minister of Fire

    Joined:
    Oct 5, 2007
    Messages:
    1,253
    Loc:
    Northwood, NH
    Thanks. It's hard to read in the photos, but you can see my nameplate on the Trinity, just over the NTI logo. Those aluminum plates will last a long time, and I try to make sure my work will still be considered good (even if outdated) 30 years from now.

    Well, the tapping on the feed valve, and the expansion tank, and the hydraulic separator, and the pressure guage, and the drain valve are all threaded, so people tend to stick with what's there, rather than use copper/NPT adapters. The reason that those things are threaded instead of sweat is either because they are replacement items (like the feed valve, expansion tank, and pressure guage), or because replacement items need to connect to them. Iron makes sense there.

    I also tend not to swith materials. If you look to the left of the Trinity pump, there's a brass tee which is part of the factory piping (the pipe going down goes back into the boiler for the domestic hot water system). So, the nippes and tee that I installed between that and the hydraulic separator and wood boiler pump are also brass. Mostly just because of looks, but also because of galvanic action when dissimilar metals are connected (to a much lesser extent).

    In this case, I think it's simply because the pressure vessel is completely contained. In a traditional oil or gas boiler, the pressure vessel is within an inch of the jacket, if not closer. Here, the pressure vessel is suspended inside the boiler - the only connections are the two pipes that go through. I think they assume that the relief valve will be connected on the back, where the expansion tank is, but it was too crowded back there so I put it up top where it would be easier to service.

    Greenwood also expects a good portion of their boilers to be installed as open systems, in which case there is no relief valve.

    Other random notes:

    The two PVC fittings (top and bottom of the Trinity) are the air intake (bottom) and flue outlet (top). It vents directly though the wall, and it burning outside air rather than indoor air (something I wish the wood boilers did).

    The clear plastic gadget below the Trinity is a condensate trap. Rather than the tradition P-trap, NTI uses this floating-ball contraption which provides a more positive seal and can be easily disassembled for cleaning.

    There are actually four different voltages in this system. The Trinity and the wood boiler operate on 120V. The air handler and A/C condenser operate on 220V. And the controls operate on 24V and 5V, depending on the particular control.

    I removed the silly plug-in cord from the wood boiler and wired it with MC like everything else. I added a switch (to the right of the Trinity) that allows it to be disabled, so it isn't wasting power attempting to run when the owner doesn't have a fire in it.

    The ZVC is a four-zone unit, which means that future expansion is possible. The owner has a pool, which could be heated with this system, and connecting a storage tank might require another of those zones, depending on exactly how it was wired and piped.

    The overheat control is a simple aquastat that over-rides the thermostat signal to the second air handler, dumping the excess heat there.

    Since the house has an automatic-start propane generator, we didn't have to worry about any sort of battery backup or gravity system.

    Joe
  4. brad068

    brad068 Feeling the Heat

    Joined:
    Nov 20, 2007
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    445
    Loc:
    Central Wisconsin
    The two PVC fittings (top and bottom of the Trinity) are the air intake (bottom) and flue outlet (top). It vents directly though the wall, and it burning outside air rather than indoor air (something I wish the wood boilers did).

    Garn wood boilers use outside air for combustion. Not only is it safer, but because of the amount of air they move thruogh the combustion a normal building would probably to "tight" for them to operate correctly.
  5. rreihart

    rreihart New Member

    Joined:
    Aug 2, 2007
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    Loc:
    Central PA
    Joe, thanks for sharing the photos. I'm with Eric in that I love to look and learn. Now a few questions if you don't mind.

    What type of pex do you use and in what applications? Only long runs, or everything but near boiler? What temps are you comfortable to with pex?

    Do you often use the hydraulic seperator instead of close tees? Does it do a better job with air than a scoop?

    Thanks, Rob.
  6. BrownianHeatingTech

    BrownianHeatingTech Minister of Fire

    Joined:
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    1,253
    Loc:
    Northwood, NH
    It's Wirsbo/Uponor, in this case. There are a variety of pex-a products out there. Wirsbo is common around here, and of high quality. I also happen to like the translucent nature, since it gives some indication of the water quality, and lets me watch for air bubbles during zone purging.

    Typically, pex gets used whenever we are making a run of any real distance, unless it is a relatively straight shot (the air handler in this case is piped with copper). Copper is less flow restriction, in terms of straight pipe, so it's used when possible, but it's a lot more labor and that flow advantage starts dropping off when you start adding fittings.

    In this case, the pex runs across the ceiling to the back of the house, then over to the side, when it comes down the wall to a buried conduit, snakes through there to the other building, then back up to the ceiling, across the first (unfinished) basement/crawlspace, and into the second (finished) basement/crawlspace that holds the air handler for that building. We would have had a lot of fittings in copper to accomplish the same thing, versus two continuous pex pipes.

    Stick with the rated temperatures when dealing with pex. 200 is typically the maximum, depending on pressure. There are different ratings for pex-a and pex-al-pex, so keep an eye on that, too, if you think you may have to deal with higher temp/pressure combinations.

    Almost always. By the time I buy a Spirovent, a sediment trap, and pipe those extra fittings, the material and labor have exceeded the hydraulic separator's cost.

    Most things do a better job than an air scoop. The air scoop is literally that - they assume that the air bubbles will be in the top third of the pipe (hence wanting 18" of straight pipe before the scoop, to allow things to settle out), and there is a diverter vane that directs the top third of the water into a small expansion chamber, slowing the flow so the bubbles can precipitate out. It will catch large bubbles, but the small bubbles are more affected by flow than by bouyancy, so they just head back down with the water.

    The hydraulic separator includes a microbubble resorber, similar in operation to a Spirovent or other standalone air eliminator. Basically, a screen or grid is in the water's path, and the bubbles adhere to it as they pass, then working their way up along the wire or sheetmetal until they get to the top and are released by the vent. The Caleffi hydraulic separators also include a service check for the air vent, so it can be removed without draining the system (removing the vent causes the valve to close, sealing that port). The only complaint I have is that the adhesive used for the insulation tends to come undone, but a couple of zip ties solves that problem with ease.

    Joe
  7. henfruit

    henfruit Minister of Fire

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    Loc:
    New Hampshire-Maine border
    nice pics joe,do i get any advertising comission? take care
  8. BrownianHeatingTech

    BrownianHeatingTech Minister of Fire

    Joined:
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    Messages:
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    Loc:
    Northwood, NH
    Not for photos. If you refer someone to me (and they remember to tell me that they were referred) you get a 1% commission if they purchase a system.

    Joe
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