Intellicon HW+ fuel economizer anyone?

[MCPO]

.............I`m a retired electrician but one who feels his common sense and mechanical mental abilities are still functioning well and assuming there are also some good mechanical and experienced minds here I`d like to run this thru this forum for thought or someone with this product experience that is very similar to an outdoor air temperature sensor controlling boiler operation.
I just ordered what appears to be a decent product in hopes of increasing the efficiency of my oil heating system. Not that mine is old or inefficient but even a small improvement helps and for $210 delivered it seems like it`s well worth trying.
(broken link removed)
Comments welcome.

 

[steam man]

I am an engineer and happened to buy and install one on the cheap. It will allow the boiler to use any residual heat before letting the burner fire down to a low of about 140 deg. The manager will look at the rate of heat load and anticipate firing the burner based on that. The idea is lessen the number of cycles the burner fires and theoretically increasing efficiency. I think the load mass and the boiler mass come into play in determining the amount of possible savings you can expect. My boiler is probably no more than 7 gallons so I know I am not getting as much residual heat scavenging as a larger volume unit. Also, if the heat load is more than the residual heat in the boiler the burner will have to fire anyway. I think these do work but the amount of savings is going to be dependent on each individual system.

Mike

 

[MCPO]

I am an engineer and happened to buy and install one on the cheap. It will allow the boiler to use any residual heat before letting the burner fire down to a low of about 140 deg. The manager will look at the rate of heat load and anticipate firing the burner based on that. The idea is lessen the number of cycles the burner fires and theoretically increasing efficiency. I think the load mass and the boiler mass come into play in determining the amount of possible savings you can expect. My boiler is probably no more than 7 gallons so I know I am not getting as much residual heat scavenging as a larger volume unit. Also, if the heat load is more than the residual heat in the boiler the burner will have to fire anyway. I think these do work but the amount of savings is going to be dependent on each individual system.

Mike

Thanks for your reply Mike, I`m not expecting miracles but it`s already on order and I`ll have something to play with.
My boiler is a V73 Burnham with a Beckett AFG burner installed in 1996 and it holds 10.8 gals.
I have 4 zones (2400 sq ft) which include a 40 gal Boiler Mate storage tank. Hopefully this thing will allow me to squeeze a bit more out of a gallon of oil .

 

[steam man]

Just figure the smaller the heat load the more it would seem to save if your burner doesn't have to cycle. I think my burner nozzle size is a little on the large size so I think it still is short cycling more than it should. I may be downsizing the nozzle this spring. Longer steady burns are much more efficient. Its just a balancing act.

Mike

 

[Chris S]

I've installed about a dozen of them. You sound like a great candidate for real savings. From what I've seen they work better the more mass ( cast iron vs steel, or low mass boilers), and zoned systems generally respond well to these.
Every one that I installed reported over 15% savings, some as high as 28% savings
The high was a 6 zone CI boiler that is oversized. The low a 2 zone stell boiler with a hot water coil.
In my opinion- not as good as outdoor reset, but certainly less money and a quicker install.
Imagine the remifications if everyone were able to cut fuel consumption 15%? We could afford to take road trips again!!

 

[MCPO]

I've installed about a dozen of them. You sound like a great candidate for real savings. From what I've seen they work better the more mass ( cast iron vs steel, or low mass boilers), and zoned systems generally respond well to these.
Every one that I installed reported over 15% savings, some as high as 28% savings
The high was a 6 zone CI boiler that is oversized. The low a 2 zone stell boiler with a hot water coil.
In my opinion- not as good as outdoor reset, but certainly less money and a quicker install.
Imagine the remifications if everyone were able to cut fuel consumption 15%? We could afford to take road trips again!!

I`m encouraged by your comments Chris. I`ll probably have mine in a day or two and I will connect it asap and as soon as I can determine how well it works , if at all, I`ll report back.

 

[MCPO]

OK, It`s installed and working . It`s really simple to connect especially for a handy homeowner or do it yourself person.
Burner seems to run more efficiently since residual heat in boiler is being utilized before it kicks on. I`ll probably need the whole year to determine the fuel savings if any , but it does look promising from here.

 

[MCPO]

OK,
Update. I left for 10 days last week and came home to find the Itellicon HW+ recording a substantial 28.5% average savings of burner cycles since installing the controller. Not much heating lately but with 4 adults showering daily and hot water for washer loads.
I`m not sure how this is going to translate into fuel savings since the burner cycles are less often but longer lasting but it seems pretty obvious that it is going to be more efficient with less wear and tear and some savings on the electricity used.
I`ll still need a year or so to evaluate it`s worth but it is encouraging.

 

[kbjelka]

Mine has been in since last fall and reports 29.9% savings over the time period. I installed a pellet stove at the same time so it's hard to pinpoint savings but it definitely works as advertised and I believe the savings are substantial. I am pretty sure it has paid for itself already. My install required the domestic hot water sensor. Install and programming was pretty straight forward. Only tricky part I found was getting the insulation neatly wrapped around the sensors. Posted on this last year when oil was high and got surprisingly little interest.

 

[MCPO]

At this moment mine is reading out at 30.4 % savings . A total of 43.7 hours saved (burner not running but circulator salvaging residual heat) , burner running time of 139.9 hours.
This 30.4% should not be taken as actual savings since there always were times when the circulator ran without the burner firing prior to the Intellicon install but these times have certainly increased, hopefully at least 10% as the product claims.
Again this is for 4 adults ,showers , laundry, and whatever heat used on the cooler April / May days (unit installed 14 April)
My nozzle is .85 gal per hour so it should translate to approx 119 gals of oil used so far.
At this point I can`t tell if there is any actual savings since I did not record time on/off data prior to installing the Intellicon but I do know for sure that this has extended the circulator run times so there should be a savings . I`ll know better at the years end.

 

[Chris S]

Gio,
I think your math is incorrect. I spoke to the people at Intellidyne about this, and if my memory is correct, the HW+ is not counting the time that the burner is off, between you hi & lo limits, only the additional time the burner is held off from when it normally would fire. I'm going to verify this.
Chris

 

[MCPO]

Gio,
I think your math is incorrect. I spoke to the people at Intellidyne about this, and if my memory is correct, the HW+ is not counting the time that the burner is off, between you hi & lo limits, only the additional time the burner is held off from when it normally would fire. I'm going to verify this.
Chris

Chris,
I really wish you are correct but if so that would sound like it is too good to be true and would result in far better savings than I can presently estimate . I find it hard to believe the control can make calculations that would be dependent on an unknown original preset high and low. I mean how would the HW+ know what the original normal firing settings were?

Correction:
Scratch the last two sentences above! I recall that the unit needed 72 hrs to make those calculations.

 

[kbjelka]

Gio,
I think your math is incorrect. I spoke to the people at Intellidyne about this, and if my memory is correct, the HW+ is not counting the time that the burner is off, between you hi & lo limits, only the additional time the burner is held off from when it normally would fire. I'm going to verify this.
Chris

Chris,
I really wish you are correct but if so that would sound like it is too good to be true and would result in far better savings than I can presently estimate . I find it hard to believe the control can make calculations that would be dependent on an unknown original preset high and low. I mean how would the HW+ know what the original normal firing settings were?

The Intellicon is wired between the burner circuit and the aqua-stat. and also has sensors for boiler output pipe and the domestic coil if used. It knows when a zone calls for heat those burner calls are controlled through a combination of the thermostat and the aqua-stat low and high limit settings. The low limit will keep domestic hot water ready which is a good source of heat fo scavenging, It knows the current temperature from the hot water delivery pipe sensor. It will turn on the circulator during a call for heat but suppress burner ignition until the output pipe sensor falls below a threshold thereby scavenging reserve heat in the burner. This is the economizing mode, when there is a call for the burner but the HW+ holds it off. Average % of savings is a calculation of economizing time divided by total burner call time. All the various thresholds can be programmed bu it comes with a good baseline program out of box.

 

[kbjelka]

Becket gives a pretty good explanation here...

http://training.rwbeckett.com/modules/HeatManager/Self/Beckett-HeatManager-selfPace.html

Intellicon makes the Becket units but the intellicons are nicer...

 

[MCPO]

Gio,
I think your math is incorrect. I spoke to the people at Intellidyne about this, and if my memory is correct, the HW+ is not counting the time that the burner is off, between you hi & lo limits, only the additional time the burner is held off from when it normally would fire. I'm going to verify this.
Chris

Chris,
I really wish you are correct but if so that would sound like it is too good to be true and would result in far better savings than I can presently estimate . I find it hard to believe the control can make calculations that would be dependent on an unknown original preset high and low. I mean how would the HW+ know what the original normal firing settings were?

The Intellicon is wired between the burner circuit and the aqustat. and also has sensors for Hydronic output pipe and the domestc coil if used. It knows when a zone calls for heat those burner calls are controlled through a combination of the thermostat and the Auqastat low and high limit settings. Low limits will keep domestc hotwater ready and povide heat fo scavengeing, It knows the current temperature from the hot water delivery pipe sensor. It will turn on the circulator during a call for heat but suppress burner ignition runtil the output pipe sensor falls below a threshold thereby scavenging reserve heat in the burner. This is the economizing mode, when there is a call for the burner but the HW+ holds it off. Average % of savings is a calculation of economizing time divided by total burner call time.

I pretty well understand the above and am going to wait for verification/clarification from Chris on the off time (econ mode) that the HW+ records.
That has to be either the total time the burner does not run while the circulator is scavenging heat or the additional time that the HW+ allows for .
OK, it takes (72 hrs?) before it begins to display the savings so I would have to think it does in fact compute those original settings and run time .

However, as I wrote earlier, my savings (this AM) reads out at 30.8% , econ time reads 43.9 hrs vs 140 hrs run time. If the 43.9 hrs were only additional scavenging time which is very close to 33% and that would seem indicate an enormous savings but that 33% is not going to translate to a 33% savings on oil used since the burner will run for longer periods to recover.

 

[MCPO]

Gio,
I think your math is incorrect. I spoke to the people at Intellidyne about this, and if my memory is correct, the HW+ is not counting the time that the burner is off, between you hi & lo limits, only the additional time the burner is held off from when it normally would fire. I'm going to verify this.
Chris

Chris,
I really wish you are correct but if so that would sound like it is too good to be true and would result in far better savings than I can presently estimate . I find it hard to believe the control can make calculations that would be dependent on an unknown original preset high and low. I mean how would the HW+ know what the original normal firing settings were?

The Intellicon is wired between the burner circuit and the aqustat. and also has sensors for Hydronic output pipe and the domestc coil if used. It knows when a zone calls for heat those burner calls are controlled through a combination of the thermostat and the Auqastat low and high limit settings. Low limits will keep domestc hotwater ready and povide heat fo scavengeing, It knows the current temperature from the hot water delivery pipe sensor. It will turn on the circulator during a call for heat but suppress burner ignition runtil the output pipe sensor falls below a threshold thereby scavenging reserve heat in the burner. This is the economizing mode, when there is a call for the burner but the HW+ holds it off. Average % of savings is a calculation of economizing time divided by total burner call time.

I pretty well understand the above and am going to wait for verification/clarification from Chris on the off time (econ mode) that the HW+ records.
That has to be either the total time the burner does not run while the circulator is scavenging heat or the additional time that the HW+ allows for and I`m now inclined to believe it is the extended additional time the HW+ allows for.
Since it takes (72 hrs?) before it begins to display the savings I would have to think it does in fact compute those original settings and run time .

However, as I wrote earlier, my savings (this AM) reads out at 30.8% , econ time reads 43.9 hrs vs 140 hrs run time. If the 43.9 hrs were only additional scavenging time which is very close to 33% and that would seem indicate an enormous savings but that 33% is not going to translate to a 33% savings on oil used since the burner will run for longer periods to recover.

But I`ll still be quite happy with even a 10% savings of oil.That would be significant.

 

[kbjelka]

I'm not convinced it is running longer to recover. Don't forget it is providing residual heat from the last cycle until it allows the burner to fire so it is working the temp of the area back up even when economizing. I think it would be tough to get accurate numbers this time of year. I think mine has been so high over the past 10 month period because half my square footage is completely heated via pellet so I leave that zone at 50 degrees and it essentially never calls for heat. My burner is now way over sized for the SF is is heating which is what the economizer thrives on.

 

[MCPO]

I'm not convinced it is running longer to recover. Don't forget it is providing residual heat from the last cycle until it allows the burner to fire so it is working the temp of the area back up even when economizing. I think it would be tough to get accurate numbers this time of year. I think mine has been so high over the past 10 month period because half my square footage is completely heated via pellet so I leave that zone at 50 degrees and it essentially never calls for heat. My burner is now way over sized for the SF is is heating which is what the economizer thrives on.

Prior to installing mine my burner swing was 165-190. It is now 135-180 . Thats 30 degree diff on the low end and 10 degrees on the high end.
Since it now starts up again at 135 it has to run longer to get up to 180.

 

[kbjelka]

I'm not convinced it is running longer to recover. Don't forget it is providing residual heat from the last cycle until it allows the burner to fire so it is working the temp of the area back up even when economizing. I think it would be tough to get accurate numbers this time of year. I think mine has been so high over the past 10 month period because half my square footage is completely heated via pellet so I leave that zone at 50 degrees and it essentially never calls for heat. My burner is now way over sized for the SF is is heating which is what the economizer thrives on.

Prior to installing mine my burner swing was 165-190. It is now 135-180 . Thats 30 degree diff on the low end and 10 degrees on the high end.
Since it now starts up again at 135 it has to run longer to get up to 180.

As I understand it the high limit is just a limit to keep the system from approaching the boiling point. The low limit is to keep the system at a minimum temperature to provide domestic hot water. The install manual does say to keep the high limit as high as possible to maximize savings. Not sure why your high limit would change unless someone lowered it but I understand that the low would bottom out a bit during a call for heat due to the economizing. The system does not need to get back to high limit to shut off but rather the zone swing on the thermostat needs to be satisfied to shut off the call for heat. Since it is heating the zone during the economizing period it's not like it needs to make up for that time.

 

[MCPO]

My boiler tech told me to lower my high limit 10 degrees in April thru Nov being the temps are warmer and 180 vs 190 could save a bit.

 

[Chris S]

Or you could get an outdoor reset controller, and save a lot!!

 

[MCPO]

Or you could get an outdoor reset controller, and save a lot!!

Can you elaborate on the outdoor reset controller?

 

[Chris S]

Outdoor reset control uses outdoor air temperature input to raise and lower your boilers target temperature. Modulating condensing boilers have it built in as will all of our new boilers in a few years. Meanwhile you can add it on to any boiler. We use Tekmar controls. They have strap on sensors - similar to the economizer, and take control away from the boilers aquastat controller to modulate the temperature.
The reset controller can be programmed to a low limit ( 140 usually for cast iron boilers) and a high limit - usually 180 or 190. Basically a straight line graph then exists with outdoor temp on 1 axis and boiler target temperature on the other axis.
This is an oversimplification, but ...

In my experience ODR will save more than the Intellicon units, but they cost more & are harder to install. If you're spending over $4000/ yr on fuel, I would look at ODR.
You could have both controls on your boiler, but the savings might not justify it.
More research for you sorry

 

[MCPO]

Outdoor reset control uses outdoor air temperature input to raise and lower your boilers target temperature. Modulating condensing boilers have it built in as will all of our new boilers in a few years. Meanwhile you can add it on to any boiler. We use Tekmar controls. They have strap on sensors - similar to the economizer, and take control away from the boilers aquastat controller to modulate the temperature.
The reset controller can be programmed to a low limit ( 140 usually for cast iron boilers) and a high limit - usually 180 or 190. Basically a straight line graph then exists with outdoor temp on 1 axis and boiler target temperature on the other axis.
This is an oversimplification, but ...

In my experience ODR will save more than the Intellicon units, but they cost more & are harder to install. If you're spending over $4000/ yr on fuel, I would look at ODR.
You could have both controls on your boiler, but the savings might not justify it.
More research for you sorry

Thanks Chris,
I was just reading a bit about the ODR from this link ( (broken link removed)) and they claim a similar 10% + savings too just as the Intellicon does.
From what I gather the general consensus is as you stated, the ODR is somewhat better than an indoor unit.
Being that I only use about 600 gals a yr for heat (+150-200 gals for hot water) I`m gonna be content for now with the Intellicon in hopes it does in fact save me at least 10%.
It`s simple enough to adjust my high limit come warmer/colder outdoor temps. Surely not as accurate as an ODR but maybe close enough.