My Portage & Main Optimizer 250 Install (w/Pics)

[tinner_bob]

A couple of more questions, if I may.

Hot burn chamber reload question.

Is there a bypass that you open before opening the loading door?
or
does the fan just shut off and the air damper close.

If this is the case isn't there a lot of smoke and heat coming out at you while reloading.


When the fan shuts down. does the smoke still exit through the bottom reaction chamber?

Sorry for being somewhat repetitive. But I do want to understand this.

Sounds like you all are loving these owb's

Thanks,
Bob

 

[J1m]

Bob,

If I understand your question correctly, you might have it backwards. You WANT to load the furnace with the fan on. The fan stokes the fire from the top and the back - but you get very little smoke out the door with it running. Sure, there's some heat, but it's not unbearable. I wear work gloves and just throw my logs in so I'm not near the open door for very long.

Contrast the enormous billowing plume of smoke when you open the door without the fan running and the coals are just smouldering...Can you say COUGH? Yes, the smoke still exits the stove out the bottom of the fire box and through the series of heat exchangers before it goes out the stack. There's no where else for it to go.

Oh, there is the option to turn off the fan with a little black switch on the top right of the stove but the only time I use that switch is when the fan is running and I want to clean the boiler.

 

[MattNH]

I couldn't agree more Jim. Load with the fan on and turn it off when cleaning. Filling when the fire is smoldering is asking for a smoke bath.

 

[Marc]

Here's a question for you gents- the boys with the indoor version of this type of version (Tarm, Eko, Froling et al) generally burn them all out until the house is warm or until the load is gone to avoid idling. Many of them use large thermal mass water storage so they can fire the boiler and store excess heat so they don't have big temp swings in the house.

Do you generally use the MO of most other outside wood boilers even though they're gassifiers? I.E., let the t-stats call for heat as the house needs it and keep the boiler topped up, and just deal with the inevitability of idling? Does anyone try to burn them in complete cycles to get the best efficiency and cleanest burn? Anyone considered using them with heat storage?

 

[tinner_bob]

Big THANKS guys!

 

[J1m]

Here's a question for you gents- the boys with the indoor version of this type of version (Tarm, Eko, Froling et al) generally burn them all out until the house is warm or until the load is gone to avoid idling. Many of them use large thermal mass water storage so they can fire the boiler and store excess heat so they don't have big temp swings in the house.

Do you generally use the MO of most other outside wood boilers even though they're gassifiers? I.E., let the t-stats call for heat as the house needs it and keep the boiler topped up, and just deal with the inevitability of idling? Does anyone try to burn them in complete cycles to get the best efficiency and cleanest burn? Anyone considered using them with heat storage?

I'm not sure I entirely understand your question, Marc.

I've been running my stove since the third week of September and the temperature fluctuates exactly zero degrees inside my house unless I change the thermostat up or down in one of the 7 zones.

My boiler temps are at 180 fan off, 170 fan on. So there are several periods of "inevitable idle time" each day. In fact I welcome those periods because I'm not burning any wood nor am I paying the electric man to run my fan.

There are two pumps running through my heat exchanger 24/7. One is the supply/return for the OWB and one is for supply/return for the oil furnace. Whenever one of my zones calls for heat, that pump will activate and send warm water through that loop.

Im not sure what the advantage of having mass water storage would be. I'd still be heating the 250 gallons in the OWB and the water in the mass storage tank...And probably burn more wood.

 

[Marc]

I'm not sure I entirely understand your question, Marc.

I've been running my stove since the third week of September and the temperature fluctuates exactly zero degrees inside my house unless I change the thermostat up or down in one of the 7 zones.

My boiler temps are at 180 fan off, 170 fan on. So there are several periods of "inevitable idle time" each day. In fact I welcome those periods because I'm not burning any wood nor am I paying the electric man to run my fan.

There are two pumps running through my heat exchanger 24/7. One is the supply/return for the OWB and one is for supply/return for the oil furnace. Whenever one of my zones calls for heat, that pump will activate and send warm water through that loop.

Im not sure what the advantage of having mass water storage would be. I'd still be heating the 250 gallons in the OWB and the water in the mass storage tank...And probably burn more wood.

The advantage of having storage is being able to burn a full load of wood without idling, all at once and gaining efficiency. You lose efficiency at idle and on every restart. So the idea is, you burn the boiler when it's convenient for you to do so, until you've satisfied the heat demand of the house and increased the temperature of your storage to whatever your design temp is. Then as there are additional heat demands from the central heat, or DHW, or whatever, they draw heat off the storage. It's a common set up for indoor gassifiers and required for the real fancy indoor biolers with microcontrollers and lambda sensors (e.g. Froling, Effecta).

 

[J1m]

The advantage of having storage is being able to burn a full load of wood without idling, all at once and gaining efficiency. You lose efficiency at idle and on every restart. So the idea is, you burn the boiler when it's convenient for you to do so, until you've satisfied the heat demand of the house and increased the temperature of your storage to whatever your design temp is. Then as there are additional heat demands from the central heat, or DHW, or whatever, they draw heat off the storage. It's a common set up for indoor gassifiers and required for the real fancy indoor biolers with microcontrollers and lambda sensors (e.g. Froling, Effecta).

Sounds like a total PITA. I just want to throw wood in the thing twice a day and forget about it. Thinking about heat demands in the house, guaging exactly how much wood would be used to heat the water in the boiler plus the water in a separate bulk storage tank all at once plus thinking about the outside temperature and wind on any given day. Woah. That's a whole lot like work!!!

I'm no whiz at this stuff, so please educate me: I don't quite understand how you lose efficiency.

When idle, this boiler acts basically like a 250 gallon bulk storage tank that's constantly circulating warm water through the heat exchanger inside. When the temperature of the water gets down to 170, the fan kicks on and only burns wood until the water temp gets up to 180. This on/off cycle takes approximately 30 minutes. As it lays dormant - very very little wood is burned. When the fan goes on, gasification happens within 10-15 seconds so it's heating the water almost immediately and burning wood only during this time.

Even if you're able to convince me that you lose some efficiency without using bulk storage, thereby burning a little more wood, what you described above hardly sounds like an efficient way to spend one's time.

 

[THE PLUMMER]

If one only sees only a few degrees temperature drop or Delta T on your supply and return, It could be too big of pump or lack of heat exchange going on. For indoor boilers each type of radiation has a design DT, baseboard=20, air handler=10-16, infloor 10 for warming or idling design and 20 for heating, etc. This exchange of temperature or btu's givin off at a heat source is important to control comfort and efficiency. Normal design temp for most applications is 20 degreez delta T. There are specific designs that may use a different system DT.

 

[Marc]

Sounds like a total PITA. I just want to throw wood in the thing twice a day and forget about it. Thinking about heat demands in the house, guaging exactly how much wood would be used to heat the water in the boiler plus the water in a separate bulk storage tank all at once plus thinking about the outside temperature and wind on any given day. Woah. That's a whole lot like work!!!

I don't have one of these setups, but from what I gather, the system is meant to be a convenience, not a PITA. In other words, the system is designed such that when you're burning a load of wood, the house heating demand is satsified first (if there is one) and the excess goes into storage, all automatically through thermal controls. You don't ever hardly think about it after it is designed.

I'm no whiz at this stuff, so please educate me: I don't quite understand how you lose efficiency.

When idle, this boiler acts basically like a 250 gallon bulk storage tank that's constantly circulating warm water through the heat exchanger inside. When the temperature of the water gets down to 170, the fan kicks on and only burns wood until the water temp gets up to 180. This on/off cycle takes approximately 30 minutes. As it lays dormant - very very little wood is burned. When the fan goes on, gasification happens within 10-15 seconds so it's heating the water almost immediately and burning wood only during this time.

This is an assertion, but may not be true. The efficiency lost is from the smoldering during idle and at every restart. I'd venture to say it's significant enough to a lot of people, i.e. people with indoor versions of these things try to achieve full burns with no idling and mid burn restarts. There's even a company that designs the boiler and water storage as one unit (GARN |).

Even if you're able to convince me that you lose some efficiency without using bulk storage, thereby burning a little more wood, what you described above hardly sounds like an efficient way to spend one's time.

We know two things for sure
1) Idling and restarts are not as efficient as a full load burn
2) Lower efficiency means more wood, more unburnt gas

How much more wood is needed and how much more smoke produces I'm sure varies based on myriad of factors. I know in the summer if you want to do DHW with a wood appliance, storage makes a lot of sense. And determing the cost of the extra wood and smoke vs. the cost of the storage system is something a person has to and should choose for oneself. I'm not here to convince you or anyone else of anything, just to ask questions and learn. And share knowledge if I can.

 

[CrappieKeith]

I have an EKO 25 and like it but it seems a very fussy wood boiler. When it comes to gassifiers you need dry wood and there is no way around it. It wont gassify if the wood is moist. The drier the better, if the wood fizzes and water comes out when burning it's too wet.

Fussy ya say.....it is impossible to make all of the btu's in a lb of wood when it is wet enough to sizzle.
Do yourself a favor and put up the wood sooner...let it dry out...that is if you want an efficient clean wood burner.