Heating with Thermal Storage and Low Flow Temps

[JohnDolz]

I'm not sure if this topic has been beaten to death yet or not. I am still really new here but am very impressed with some of the knowledge, engineering and equipment out there. I'm happy to see the amount of info around Thermal Storage design and piping but I haven't seen anything about leveraging a mixing valve to get better "mileage" out of the storage. I have attached a few pictures, as a long time Hearth Member educated me that seeing goes a long way. One photo is of my Shunt Valve Controller (everything is in Celsius). This system is controlled by an Outdoor Reset (see Heat Curve Photo) but has the ability to be overridden by an Indoor Sensor should the Temp vary too far from target either way.

I have the Indoor Sensor upstairs as upstairs is 1 big heating loop. The Heat Curve I have chosen to use gets me to about 70F Upstairs and with the help of thermostats keeps my downstairs (2 loops) at 72F.

My boiler controls this stuff but I understand that there are controllers that can do this as long as you have storage. I have been asked about my emitters so I have included a photo of these as well. They are standard baseboard with some aftermarket covers for looks. My plumbers swears I am losing 30-40% of BTU power due to these covers. I also have a Modine Hydronic Heater heating an unfinished basement.

I have chosen a Heat Curve of 52. If you look at the heat Curve graph and look at the curve that intersects 50C and -15C, just shift it up 2 degrees and that is what I am tracking.

To tie this info to something, I am heating about 5000 sqft (includes a 1500 sqft basement at 67F & a 500 sqft addition with an UNDER powered toe heater) and keep the house at 70 -72 as described. Looking at the Shunt Control you see that the Outdoor temp is 1C (34F) and that my target flow temp is 40C (104F); at the moment of the photo actual is 37C (99F). The whole day was about 34F with no sun. I started a fire this AM around 7:00 AM (65kw = 200k btu hr) and got the top tank to 190F. It is now a little after 6:00 PM and top tank is at 181F.

This is VERY different from last year where I felt I was always pressing to charge tanks. I'm curious as to others experiences.

 

[TCaldwell]

Hi John,
I'm not surprised only alot jelous, heating your house with what my system would consider useless. After seeing your setup with your emitters, I spoke to several mechanical engineers that specialize in hydronic design and by the way participate here. All three stated outdoor reset with indoor feedback being supplied from storage would be able to satisfy the house demand with lower water temps, these lower water temps would increase the useable storage. This is possible because a properly designed reset system's circs seldom shut off, always delivering the minimun heat required to maintain temp with no on/off wasted energy or cold spots. One engineer stated that as well as the system works with suspect emitters, he would start with changing to low temp emitters first to reduce system flow, then employ reset for further savings. In any case weather the cart before the horse does not matter, this appears for a older guy a way to handling less wood!
I was also informed that us boiler manufacturers will soon be federally mandated to incorporate odr.

 

[cpeltier]

I haven't seen anything about leveraging a mixing valve to get better "mileage" out of the storage.

This is indeed one strategy. The ideal situation is to pick off the coolest temperature from your storage that will work for your current outdoor reset heating curve point but since this can get complicated a floating action mixing valve or injection pump (which I use) go a long way to maximize the high temp water in storage.

 

[JohnDolz]

This is indeed one strategy. The ideal situation is to pick off the coolest temperature from your storage that will work for your current outdoor reset heating curve point but since this can get complicated a floating action mixing valve or injection pump (which I use) go a long way to maximize the high temp water in storage.

Thanks for the input. I had to go to PexUniversity (via Google) to get an understanding of what you are doing with an injection pump. Pretty much the same result as a shunt valve. Are you changing your target temp via some type of controller or simply zeroed in on the lowest temp that will meet your needs at target that? PexU made reference to Greenhouses, I happen to have talked to a local greenhouse that is installing a beautiful huge woodchip boiler with storage and he gave me a little education on mixing. I never gave it thought before but he pointed out that with thermal gain and radiant floors running low temp is critical for them..

 

[JohnDolz]

Hi John,
I'm not surprised only alot jelous, heating your house with what my system would consider useless. After seeing your setup with your emitters, I spoke to several mechanical engineers that specialize in hydronic design and by the way participate here. All three stated outdoor reset with indoor feedback being supplied from storage would be able to satisfy the house demand with lower water temps, these lower water temps would increase the useable storage. This is possible because a properly designed reset system's circs seldom shut off, always delivering the minimun heat required to maintain temp with no on/off wasted energy or cold spots. One engineer stated that as well as the system works with suspect emitters, he would start with changing to low temp emitters first to reduce system flow, then employ reset for further savings. In any case weather the cart before the horse does not matter, this appears for a older guy a way to handling less wood!
I was also informed that us boiler manufacturers will soon be federally mandated to incorporate odr.

Hi Tom - Thanks but I have no doubt that in no time you will far surpass what I am doing and I will be the jealous one. The cost of the low temp emitters caused me to think I would just run constant flow through my existing emitters and see what happens. I believe the difference is just more lineal feet of tubing and fins but I can be wrong. I have an addition that is powered by a toe heater, TERRIBLE! I am thinking to put more horsepower in there with a low temp emitters or possibly a minisplit because I have the opposite problem in the summer (solar). I look forward t learning what you decide to do and hearing your results.

 

[cpeltier]

Are you changing your target temp via some type of controller or simply zeroed in on the lowest temp that will meet your needs at target that?

I'm using the outdoor temperature to calculate the target temperature of my mixing system (for radiant) and modulate this using an injection pump via a PID loop. I have fan coils in the system which I also run at 125F (lowest temp that worked for my setup) and this is also controlled by another PID injection pump. I use a primary/secondary loop strategy and it extracts every BTU out of my 750 gallons of pressurized storage with excellent stratification. It is all controlled by a very powerful EasyIO FG32+ controller with web based control and full HTML 5 animated graphics. All very cool. It's all part of a much larger system that I can go into more detail if you like.

 

[JohnDolz]

I'm using the outdoor temperature to calculate the target temperature of my mixing system (for radiant) and modulate this using an injection pump via a PID loop. I have fan coils in the system which I also run at 125F (lowest temp that worked for my setup) and this is also controlled by another PID injection pump. I use a primary/secondary loop strategy and it extracts every BTU out of my 750 gallons of pressurized storage with excellent stratification. It is all controlled by a very powerful EasyIO FG32+ controller with web based control and full HTML 5 animated graphics. All very cool. It's all part of a much larger system that I can go into more detail if you like.

VERY impressive, thank you for sharing. I would love to hear more but I caution you tat it is over my head already - but I am working on learning. I am in Sales and happen to cover PA maybe we can meet one day. I'll trade you some home roasted coffee for a our and lecture. Safe to bottom line it as you believe low flow temp is the way to go?

 

[maple1]

What would your typically daily burning schedule look like?

 

[cpeltier]

but I am working on learning. Safe to bottom line it as you believe low flow temp is the way to go?

A great information resource that others have mentioned in this forum is located here: http://www.nyserda.ny.gov/-/media/Files/EERP/Renewables/Biomass/biomass-hydronics-training.pdf

To maximize the use of storage and maximize efficiency (in many different ways) it is ideal to operate your system at the lowest effective temperatures. Of course you want your storage to be as hot as possible to maximize stored BTUs. Doing this with storage can be tricky as you must do this in a way where you also minimize the return temperatures and prevent storage tank mixing. It is very important to maintain tank stratification.

Hi Maple1, I'm not sure if your asking me but I burn twice a day in the colder weather (last night 17F). When I wake up, and in the evening. Last night storage ran out (750 gallons) before I had a chance to fire and the LP boiler + HP kicked in.

 

[maple1]

I guess I was first asking John, but all input welcome though.

So how many hours of burning does that represent? Storage temps top & bottom at start & end of burn?

I changed my habits last year as I also read then observed first hand that lower temps = less wood burned. I don't do any mixing though, I just deplete my storage before I burn. Depleted = when the house can no longer maintain temp.

So typical for me would be burning 6 hours a day during the winter. Storage would be around 125/115 beginning (depending how cold & windy it is out), maybe 180/170 ending - again depending what the next 12-24 hours weather forecast is sounding like. Or thereabouts. 2700 sq.ft 20 year old two storey over 1500 unfinished basement, Slant Fin baseboard (likely more than needed for a more typical oil heat system). I don't think mixing would gain me much or be worth the work in making the changes unless I updated my emitters - but even then I'm not sure it would be worth it as I should just be able to put off lighting until storage was a bit cooler. I am thinking either way I would need to be lighting when my storage was at about the same point of depletion.

 

[cpeltier]

I guess I was first asking John, but all input welcome though.

So how many hours of burning does that represent? Storage temps top & bottom at start & end of burn?

Didn't mean to thread hijack. I'm curious what John is seeing as well.

I have a Termovar mixing valve on wood boiler and it effectively creates a 2 step tank charging process. The first run fills the tanks (750 gallon) with 165F water because the return water to the boiler (Termovar) is cold. When the Termovar sees the high return temp because the tank is full then the boiler output jumps to 185-190F and it charges again to this higher temp. If it's not that cold a half load in the boiler will charge it to 165. A full load does 180-185 depending on house load. I found this behavior to be interesting.

In the last 24 hours, two runs of about 3.5 hours each (~7 hours total). I was seeing 115/115 when depleted and 180/180 typically when full. My fan coil load wants to see at least 125F in the tanks or it will switch over to LP. The radiant load will take the storage all the way down to as low as 80/70 if I allow it depending on outdoor temps (follows an outdoor reset curve). When the tank runs out for the fan coil the fan coil and radiant load will keep pulling the tank lower so the tank temps when depleted can be all over the place depending on when I catch it. When the LP turns on below 125F the storage tanks will still assist where it can to boost the return temps from the fan coils before presented to the modulating LP boiler (8-1 turndown). The average outdoor temp in the last 24 hours was about 25F and it's a 5500 square foot house (25 years old) including a heated walk out basement.

I agree lower temps = less wood burned. Switching to pressurized storage (from a worn out unpressurized) seems to have cut my wood use down as I can extract more heat out of the storage (no delta T loss in HX) and charge hotter. I also added turbulators to my Tarm last season and that helped a lot! The combination of modifications may have cut my wood use in half!

Your 125F/115F sounds very good for the Slant Fin baseboard. I probably wouldn't touch a thing!

 

[maple1]

Your 125F/115F sounds very good for the Slant Fin baseboard. I probably wouldn't touch a thing!

Yes, it does pretty good. There was a heat loss done when I was building by a pro, and the baseboard was sized for that. I don't think I ever saw the heat loss paperwork & have no idea what happened to it (I think the installer kept it), but I am quite sure he oversized it. Which I am now quite grateful for. I did add a short section to one upstairs bedroom in a north corner a few years ago after complaints from one of my kids, and another couple very short sections at strategic spots in my downstairs office. I have a couple of spots picked out for cast iron rads if I can convince my other half - and I could 'fairly easily' add more Slant Fin if I wanted as most rooms were put in wall to wall with the enclosure.

But when it gets to the coldest days of winter, into the -20's c cloudy maybe with some wind mixed in - I am for sure heading to light before storage gets below 140.

 

[JohnDolz]

A great information resource that others have mentioned in this forum is located here: http://www.nyserda.ny.gov/-/media/Files/EERP/Renewables/Biomass/biomass-hydronics-training.pdf

To maximize the use of storage and maximize efficiency (in many different ways) it is ideal to operate your system at the lowest effective temperatures. Of course you want your storage to be as hot as possible to maximize stored BTUs. Doing this with storage can be tricky as you must do this in a way where you also minimize the return temperatures and prevent storage tank mixing. It is very important to maintain tank stratification.

Hi Maple1, I'm not sure if your asking me but I burn twice a day in the colder weather (last night 17F). When I wake up, and in the evening. Last night storage ran out (750 gallons) before I had a chance to fire and the LP boiler + HP kicked in.

Yes I have seen that document, full of great information - wish I had read it 2 years ago I would have done a few things differently. At this point I am making the best of what I have and overall I am VERY happy.

 

[JohnDolz]

Didn't mean to thread hijack. I'm curious what John is seeing as well.

I have a Termovar mixing valve on wood boiler and it effectively creates a 2 step tank charging process. The first run fills the tanks (750 gallon) with 165F water because the return water to the boiler (Termovar) is cold. When the Termovar sees the high return temp because the tank is full then the boiler output jumps to 185-190F and it charges again to this higher temp. If it's not that cold a half load in the boiler will charge it to 165. A full load does 180-185 depending on house load. I found this behavior to be interesting.

In the last 24 hours, two runs of about 3.5 hours each (~7 hours total). I was seeing 115/115 when depleted and 180/180 typically when full. My fan coil load wants to see at least 125F in the tanks or it will switch over to LP. The radiant load will take the storage all the way down to as low as 80/70 if I allow it depending on outdoor temps (follows an outdoor reset curve). When the tank runs out for the fan coil the fan coil and radiant load will keep pulling the tank lower so the tank temps when depleted can be all over the place depending on when I catch it. When the LP turns on below 125F the storage tanks will still assist where it can to boost the return temps from the fan coils before presented to the modulating LP boiler (8-1 turndown). The average outdoor temp in the last 24 hours was about 25F and it's a 5500 square foot house (25 years old) including a heated walk out basement.

I agree lower temps = less wood burned. Switching to pressurized storage (from a worn out unpressurized) seems to have cut my wood use down as I can extract more heat out of the storage (no delta T loss in HX) and charge hotter. I also added turbulators to my Tarm last season and that helped a lot! The combination of modifications may have cut my wood use in half!

Your 125F/115F sounds very good for the Slant Fin baseboard. I probably wouldn't touch a thing!

I haven't quite figured out my burn cycle as things are different for me. I was thinking 1 burn a day in the milder and 2 burns a day now that it is colder. So far 2 burns has been too much so If temps were in the 20's/30's I think an average of 1.5 burns would do it. When we were in the 40's/50's I was doing 1 burn every 3 days or so. Another thing I am thinking about and trying to time is letting my tanks run down in the 120 range and then doing 1.5 loads to get the tanks charged. My thought is reducing the # of fires I start in order to minimize the # of ramp up/ramp down's. The risk is that the lower the top tank temp gets the faster it drops so when you start getting to low #'s it can bottom out pretty quick. Last year I had my setpoint at 145 for propane boiler to kick in. This year I am at 110 and think I was at 100 earlier in the winter.

 

[Kristen]

My system is sized for one burn per day. If it is 10 degrees colder than normal (i.e. what we would normally call "cold", and 10 degrees lower than that we only get once or twice a decade) then I have to burn twice a day.

We aim to finish a burn as we go to bed so that the house is warm and the storage tanks are at max temperature. A full burn, of good, dry, hardwood) takes about 7-8 hours. In the morning the tank will provide heat for getting up, and to warm the house a bit during the day until the boiler is lit again around 3pm. If we get a bit of sunshine we get some solar gain from the windows, and are less likely to need top-up heat from storage. If it is grey, and miserable, the heating will come on during the day.

Tank temperature range is 40-90C / 105-195F. Down at the bottom end the heating is only any good for topping up during the day, when it is not seriously cold outside, which is fine most of the time as the boiler is lit at 3PM and in the 3 hours before that we have maximum chance of solar gain from the sun. Late into the evening, and first thing in the morning, we benefit from the tank temperature being at the top end, which heats the house faster (or combats colder out door temperatures )

So far this winter we have had very mild weather. I have been burning every-other-day. Generally on the in between day the storage tank is at 60C / 140F in the evening. So long as the following morning is mild that is enough to give me morning heat, following day, and then by 3PM the tank will be down to 40C / 105F. If I think the following morning will be cold then I may do a half-load, but I find that a full-load is much more efficient - some heat is wasted bringing boiler and everything else up to best operating temperature.

Only downside to every-other-day burns is that there is not enough domestic hot water, so the immersion heater, in the DHW tank, will come on overnight (we have cheaper electricity at night).

 

[JohnDolz]

My system is sized for one burn per day. If it is 10 degrees colder than normal (i.e. what we would normally call "cold", and 10 degrees lower than that we only get once or twice a decade) then I have to burn twice a day.

We aim to finish a burn as we go to bed so that the house is warm and the storage tanks are at max temperature. A full burn, of good, dry, hardwood) takes about 7-8 hours. In the morning the tank will provide heat for getting up, and to warm the house a bit during the day until the boiler is lit again around 3pm. If we get a bit of sunshine we get some solar gain from the windows, and are less likely to need top-up heat from storage. If it is grey, and miserable, the heating will come on during the day.

Tank temperature range is 40-90C / 105-195F. Down at the bottom end the heating is only any good for topping up during the day, when it is not seriously cold outside, which is fine most of the time as the boiler is lit at 3PM and in the 3 hours before that we have maximum chance of solar gain from the sun. Late into the evening, and first thing in the morning, we benefit from the tank temperature being at the top end, which heats the house faster (or combats colder out door temperatures )

So far this winter we have had very mild weather. I have been burning every-other-day. Generally on the in between day the storage tank is at 60C / 140F in the evening. So long as the following morning is mild that is enough to give me morning heat, following day, and then by 3PM the tank will be down to 40C / 105F. If I think the following morning will be cold then I may do a half-load, but I find that a full-load is much more efficient - some heat is wasted bringing boiler and everything else up to best operating temperature.

Only downside to every-other-day burns is that there is not enough domestic hot water, so the immersion heater, in the DHW tank, will come on overnight (we have cheaper electricity at night).

DHW does make things a little tricky. I ran out of runway this year but I am going to install a separate DHW loop with its own circulator pump and shunt valve. This will allow DHW demand to be answered at a different water temp than my CH. I use an Indirect Water heater (basically an insulated storage tank) and will have 2 probes going into it. One will be set at say 125F and will pull water from my storage to meet demand. The other will be set at 120 and be connected to my propane boiler. When DHW target flow temp cannot be met by my wood system the controller will turn that pump off (basically not answering the call). The when DHW drops to 120 the call will go out to my propane boiler. That is the theory anyway.

 

[maple1]

I have an ordinary 80 gallon electric water heater. I heat it with wood via a flat plate HX (and a small B&G Ecocirc on the DHW side), as another load zone. I also use a Johnson A419 controller to control it with. The A419 has a separate function that when a certain circuit is closed on it (or more exactly when that circuit gets 24v sent through it, as a thermostat circuit would), it shifts its setpoint by a certain programmable amount. I have not rigged it all up yet 'done done' - but I have a thermal switch I plan to fasten to my boiler return line just outside the boiler, under some pipe insulation. Tied to 24volts & wired through that certain A419 circuit. The end result of all that, is that when the boiler is burning and hot, my DHW heater would automatically charge up to a certain programmable amount beyond what it normally would heat to. I did have it rigged up once but the thermal switch I was using was wonky, it wouldn't go fully open. So I now 'for now', just have that circuit going through a normal light switch switch - if I want to 'charge' my DHW tank, I just flip the switch when I start a fire, then flip it the other way a couple hours later. I don't need to do that when burning for heat every day or two, but it extends my DHW range quite a bit if burning only for DHW. If I charge my DHW tank to 160, it will keep us in hot water for a couple or three days on its own before needing more charge. Now, in winter, it sits at around 125 most of the time.

So, using something like that would take some of the urgency about having to keep your storage water hot enough to make DHW all the time.

 

[Kristen]

I am going to install a separate DHW loop with its own circulator pump and shunt valve

We had a coil at the top of the Thermal Store which provided DHW in our first year. That needed top of store to be 65C / 150F minimum, which was OK in Winter but difficult in Summer with only our Solar Panels heating the huge store tank!

We now have separate DHW tank. Boiler heats DHW tank before Thermal Store, so it heats up quickly. (Solar Panels also heat the DHW tank, and then the STore (in Summer). We are now using the original coil in the Thermal Store as a pre-heat for mains water replenishing the DHW tank, so in principle the feed to the DHW tank is about 60C (unless the store is very cold). Seems to work well, but the DHW tank standing losses are more than the thermal store, hence the immersion top-up some days.

I don't think it would be worthwhile trying to "heat" my DHW tank from my thermal store, but I suppose with a suitable differential thermostat I could pump the contents of the DHW tank through the top coil in the thermal store when DHW < 65C and Thermal Store is more than, say, 10C warmer than the DHW tank.

I'd need some convincing though ... I hate adding complexity to my system ... "more things to go wrong" !!

 

[JohnDolz]

We had a coil at the top of the Thermal Store which provided DHW in our first year. That needed top of store to be 65C / 150F minimum, which was OK in Winter but difficult in Summer with only our Solar Panels heating the huge store tank!

We now have separate DHW tank. Boiler heats DHW tank before Thermal Store, so it heats up quickly. (Solar Panels also heat the DHW tank, and then the STore (in Summer). We are now using the original coil in the Thermal Store as a pre-heat for mains water replenishing the DHW tank, so in principle the feed to the DHW tank is about 60C (unless the store is very cold). Seems to work well, but the DHW tank standing losses are more than the thermal store, hence the immersion top-up some days.

I don't think it would be worthwhile trying to "heat" my DHW tank from my thermal store, but I suppose with a suitable differential thermostat I could pump the contents of the DHW tank through the top coil in the thermal store when DHW < 65C and Thermal Store is more than, say, 10C warmer than the DHW tank.

I'd need some convincing though ... I hate adding complexity to my system ... "more things to go wrong" !!

I will be the first to admit that chasing the DHW is more of fun project vs. ROI. I know I can keep it warm enough for my needs with storage temp as low as 140F, we will see how low I can go once I have this all hooked up. As mentioned I also have it tied to my propane boiler and use its Antilegionella function to make sure I kick over 140F every 14 days - target temp in Indirect DHW is 125F. In the summer I shut down the wood boiler and just let my propane boiler heat DHW. I have recently installed a solar system for electricity so at some point I may explore the value of leveraging electricity.

 

[JohnDolz]

We had a coil at the top of the Thermal Store which provided DHW in our first year. That needed top of store to be 65C / 150F minimum, which was OK in Winter but difficult in Summer with only our Solar Panels heating the huge store tank!

We now have separate DHW tank. Boiler heats DHW tank before Thermal Store, so it heats up quickly. (Solar Panels also heat the DHW tank, and then the STore (in Summer). We are now using the original coil in the Thermal Store as a pre-heat for mains water replenishing the DHW tank, so in principle the feed to the DHW tank is about 60C (unless the store is very cold). Seems to work well, but the DHW tank standing losses are more than the thermal store, hence the immersion top-up some days.

I don't think it would be worthwhile trying to "heat" my DHW tank from my thermal store, but I suppose with a suitable differential thermostat I could pump the contents of the DHW tank through the top coil in the thermal store when DHW < 65C and Thermal Store is more than, say, 10C warmer than the DHW tank.

I'd need some convincing though ... I hate adding complexity to my system ... "more things to go wrong" !!

I understand the "complexity" concern. Attached are some photos of my shunt valve & motor. As you can see it is quite simple, plumb hot water from storage and return in with a pump in front f it to pull the water through. I have a temp sensor tucked under some pipe insulation to provide flow temp. Controller sends a signal to the motor to open/close the valve. Granted it is easy for me because the controller is built into my boiler but I believe folks in the UK have been doing this for a while using an external controller.

 

[velvetfoot]

Give me a little time to digest. Appreciate the pics.

 

[velvetfoot]

I don't do any mixing though, I just deplete my storage before I burn. Depleted = when the house can no longer maintain temp.

You need a sensor, perhaps hooked up to odr, that will beep upstairs when it's time to load wood before things get too cold, and taking into account outdoor temperature. The machine being turned on will be you, as you drag yourself down the stairs.

a small B&G Ecocirc on the DHW side

For clarity, that's a stainless pump circulating dhw through the flat plate?

That Effecta is quite the cat's meow! That one screen shot is a screen that came with the boiler?

The other cat's meow thing is that controller of cpeltier! Did you put that together yourself? It's awesome.

 

[maple1]

For clarity, that's a stainless pump circulating dhw through the flat plate?

Brass, actually. It's a B&G Ecocirc E^3, model LHB08100104. A sweet little pump.

 

[JohnDolz]

You need a sensor, perhaps hooked up to odr, that will beep upstairs when it's time to load wood before things get too cold, and taking into account outdoor temperature. The machine being turned on will be you, as you drag yourself down the stairs.


For clarity, that's a stainless pump circulating dhw through the flat plate?

That Effecta is quite the cat's meow! That one screen shot is a screen that came with the boiler?

The other cat's meow thing is that controller of cpeltier! Did you put that together yourself? It's awesome.

Yes that screen is standard product. It does exactly what I want it to do with minimal work, which is perfect because I travel quite a bit and it is 1 push of 1 button for my wife to fire it up. All I have to do is make sure there is enough wood inside the basement and my wife can handle it from there. There is a tremendous amount of knowledge on this forum and some amazing systems but my wife (and probably me) would never be able to handle them.

 

[JohnDolz]

You need a sensor, perhaps hooked up to odr, that will beep upstairs when it's time to load wood before things get too cold, and taking into account outdoor temperature. The machine being turned on will be you, as you drag yourself down the stairs.


For clarity, that's a stainless pump circulating dhw through the flat plate?

That Effecta is quite the cat's meow! That one screen shot is a screen that came with the boiler?

The other cat's meow thing is that controller of cpeltier! Did you put that together yourself? It's awesome.

Just noticed where you are located. I went to RPI and am sitting in the Marriott on Wolf road as we speak. If you ever want to come take a look just let me know, I am less than 2 hour drive from you.