Outdoor Reset Control
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I use it as part of my floor heat loop. The grundfos miximizer (Tekmar electronics on board) has it incorporated and it works well. It has been my only automation other than the boiler control on the Eko 40. I have the zones balanced in a way that it is the only controll I need. I would like to use evening setback in the future, there are controls that can give a boost when the system needs to get back to full temperature and then fall back to outdoor reset.
Once my storage is functional, it will save some fuel since the boiler won't idle but store the extra heat for later.
Henk.
Once my storage is functional, it will save some fuel since the boiler won't idle but store the extra heat for later.
Henk.
ORC adjusts the boilers set point. Trying to minimize fuel use by predicting near term requirements. A handy idea for expensive fuels which are auto-fed.
I would think it is similar to having storage in a wood boiler which the fuel is manually fed.
So if you are asking if this would help save wood fuel, it would appear that it could but the fuel would have already been fed in the wood boiler case. It would need to put the fire out and save the fuel for another day.
I would think it is similar to having storage in a wood boiler which the fuel is manually fed.
So if you are asking if this would help save wood fuel, it would appear that it could but the fuel would have already been fed in the wood boiler case. It would need to put the fire out and save the fuel for another day.
An ORC may control the boiler's set point, but it can also control the storage tank's discharge temperature. Which could really help "stretch the storage".
chuck172 said:
In our case (still building storage) I don't think there is a point to do this on the boiler, the intensity of the fire will be fairly hard to control and you may not want to reduce it as most wood(gasifiers) burn most efficient at full blast. Using the heat if storage is available will safe energy for storage and when used from storage, making the storage more useful.
Also the comfort level will improve as heatloss increases with lower outdoor temps, more heat will be carried in the system to replace this loss without extra effort or your behalf. (assuming you keep the wood to the fire or have the storage charged ;-) )
Henk.
I'm thinking of controlling the setpoint of the storage to the heating zones. With a sensor outside, modulating the speed of the load circulator in sync. with the outdoor temperature.
Seems to me it might be a great move especially in the shoulder seasons.
Grundfos and Taco both make these ORC pumps.
Seems to me it might be a great move especially in the shoulder seasons.
Grundfos and Taco both make these ORC pumps.
I use a Tekmar 260 on my oil boiler at my duplex. It dropped the oil consumption from 900 gallons to 750 gallons. For oil boilers they definitely work. My Harmon PB105 has an outdoor air temp sensor as well, but since I installed at the same time I installed the PB I can't tell you if or how many pounds of pellets it has saved me, but I'm assuming it's saving 10 - 15% based on what it did for my oil boiler.
I think the tekmar 260 would only work with an oil boiler. An ORC pump or tempering valve would probably work best.
I was thinking about how to do it on a wood-fired boiler. You'd need a primary/secondary loop setup and you'd hook your circulator pump to the burner output (on the tekmar, I don't know about any of the others) and use it as a switch leg to turn off/on the main circulator. This would modulate your loop temperature depending on the load requirements. Pretty much like my oil setup, but I don't have a primary ciruclator, just one for each zone because I'm not pulling from a tank but having to fire the boiler to get heat, so in essence this is my tank.
One problem might be the primary circulator's tendency to cycle however, depending on your primary loop's storage capacity. I would imagine an inside boiler buddy/ storage tank might be needed. Maybe instead of hooking to a circulator a mixing valve could be employed?
One problem might be the primary circulator's tendency to cycle however, depending on your primary loop's storage capacity. I would imagine an inside boiler buddy/ storage tank might be needed. Maybe instead of hooking to a circulator a mixing valve could be employed?
I thought the whole basis to using a circulator as a outdoor setpoint is to modulate it. Vary it's speed to control the heat output with the outside temperature.
chuck172 said:
You have a certain amount of heat available to the zone in the primary loop. The OTR cycles the circulator on/off to keep it in the specified temp range. I'm sure there are controls that could take advantage of a multi-speed circulator but the simple ones (intellicon, heatmanager, tekmar 256-260) don't.
Some form of outdoor reset can be very useful - though it is worth noting that there are several styles of outdoor reset controllers and so forth...
Given that you have relatively little adjustment on boiler flame, temps, etc with a wood boiler, other than to increase the time spent idling, which has it's own problems, I wouldn't expect a lot of benefit from OR on a boiler with no storage. OTOH, properly configured, I would expect a LOT of benefit from a boiler with storage...
The key requirement is that the boiler be transparently able to switch between feeding the house loads and the storage system as the amount of heat being called for by the house varies, and that the house has some form of adjustable mix valve, or variable speed pump to vary the amount of heat that it is pulling... This implies that there are at least two pumps - one for the boiler - storage loop, and one for the house loop.
I would run the boiler flat out, with NO attempt to modulate it's output (other than the existing boiler controls) and charge the storage with whatever heat wasn't used for the house. However I would modulate the output of the storage system (or the boiler heat) in an effort to get the widest possible swing in my storage water temps, so as to extend the time between burns...
Gooserider
Given that you have relatively little adjustment on boiler flame, temps, etc with a wood boiler, other than to increase the time spent idling, which has it's own problems, I wouldn't expect a lot of benefit from OR on a boiler with no storage. OTOH, properly configured, I would expect a LOT of benefit from a boiler with storage...
The key requirement is that the boiler be transparently able to switch between feeding the house loads and the storage system as the amount of heat being called for by the house varies, and that the house has some form of adjustable mix valve, or variable speed pump to vary the amount of heat that it is pulling... This implies that there are at least two pumps - one for the boiler - storage loop, and one for the house loop.
I would run the boiler flat out, with NO attempt to modulate it's output (other than the existing boiler controls) and charge the storage with whatever heat wasn't used for the house. However I would modulate the output of the storage system (or the boiler heat) in an effort to get the widest possible swing in my storage water temps, so as to extend the time between burns...
Gooserider
I'm constantly trying to improve my systems efficiency by working with 500 gallons of storage and stretching it to it's max. Adding more baseboard to enable low temp. heating, then lowering the storage output temperature by some sort of boiler reset seems logical.
If you chose to load the buffer, then pull the loads this is a simple and effective piping. A variable speed control, tekmar or others, offers return protection to the boilers. The loads are supplied via a 4 way motorized mixer (it could be another injection pump) to supply the exact temperature to the system based on outdoor and indoor feedback, tekmar again.
There may be a tekmar control to do both functions from one box?
One drawback is not being able to supply the load directly from the boilers, bypassing the buffer. With dual buffer tanks, a small first one for quick start up.
I have changed my system to this setup, with 500 gallons and an EKO 40 it ramps up quickly. The tank never drops below 60 and my radiant zones can run on 90F supply.
hr
There may be a tekmar control to do both functions from one box?
One drawback is not being able to supply the load directly from the boilers, bypassing the buffer. With dual buffer tanks, a small first one for quick start up.
I have changed my system to this setup, with 500 gallons and an EKO 40 it ramps up quickly. The tank never drops below 60 and my radiant zones can run on 90F supply.
hr
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HR, could you go into more detail on the outdoor reset control with the 4way valve you're using?
in hot water said:
This seems perfect to me: Both boiler supply temperature and tank return temperature are minimized with adaptive controls, while minimum boiler return temperature is maintained.
In my situation the accumulator tank will be higher than the boiler, which I'd like to take advantage of by using thermo-siphoning to protect the system in event of power failure. Would a normally-open valve bypassing the tank-charging flo-chek do the trick?
--ewd
How would this Honeywell 4 way mixing valve do for this application?
http://dticorp.com/catalog/honeywel...ing-valve-with-p-4941.html?osCsid=992c783b42b
http://dticorp.com/catalog/honeywel...ing-valve-with-p-4941.html?osCsid=992c783b42b
I've use quite a few tekmar 4 ways with the motor and operator www.tekmarcontrols.com/literature/acrobat/d360.pdf It gets to be abn expensive package.
Another option is the tekmar 356 variable speed control. www.tekmarcontrols.com/literature/acrobat/d356.pdf
It is used with pump to vary the speed for injection mixing.
The same 356 control can be used for boiler return protection as shown on the left side of the drawing. Even with the extra pump required on the distribution side, I'll bet it come in a lot less expensive than the 4 way with motor and control. Shop e-bay for pumps and controls.
Most of the solar controls have the ability to run variable speed functions, although not weather or ODR based. I have a solar control that charges my tank with one function and has the variable speed function for boiler return protection. You need a control with the two relay outputs to do that. I've seen them for around $250.00.
Here is the piping for my system running with a solar control. The boiler loop pump P-1 runs off the control inside the EKO, on at 150, off at 140F. The hotter the boiler runs the faster P-2 runs. It ramps down to 30% as the boiler cools and then P-1 drops off. P-2 is connected via closely spaced tees at the side of the boiler (yellow piping)
hr
Another option is the tekmar 356 variable speed control. www.tekmarcontrols.com/literature/acrobat/d356.pdf
It is used with pump to vary the speed for injection mixing.
The same 356 control can be used for boiler return protection as shown on the left side of the drawing. Even with the extra pump required on the distribution side, I'll bet it come in a lot less expensive than the 4 way with motor and control. Shop e-bay for pumps and controls.
Most of the solar controls have the ability to run variable speed functions, although not weather or ODR based. I have a solar control that charges my tank with one function and has the variable speed function for boiler return protection. You need a control with the two relay outputs to do that. I've seen them for around $250.00.
Here is the piping for my system running with a solar control. The boiler loop pump P-1 runs off the control inside the EKO, on at 150, off at 140F. The hotter the boiler runs the faster P-2 runs. It ramps down to 30% as the boiler cools and then P-1 drops off. P-2 is connected via closely spaced tees at the side of the boiler (yellow piping)
hr
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![[Hearth.com] Outdoor Reset Control](/talk/data/attachments/23/23196-88325d47799ab9da6c9f2b4e897276d4.jpg?hash=5WYK7DK5Jr)
I didn't realize that the tekmar 356 variable speed control could work in conjunction with a taco 007. Thanks for the info!
chuck, there's a list of compatible circulators on page 4 of this pdf:
http://www.tekmarcontrols.com/literature/acrobat/d157.pdf
That's great. When I'm ready to go with the outdoor reset control, the tekmar 356 ($250) should do the trick.
Hi there,
Have you heard of the Intellicon HW+? It's a microprocessor-controlled, fuel-saving device for hot water (hydronic) heating systems. This unitreduces fuel consumption, wear on parts, flue emissions and electrical usage, when installed on any new or existing gas or oil burner. We have had success providing savings for our customers with these units. We carry the entire Intellidyne product line and this is our 3rd best performing economizer.
Sounds like this product might be your solution as it utilizes a method of "outdoor-air temperature reset control," but does not require an outdoor-air temperature sensor or the need to profile the building in order to adjust the "reset" controller properly. Therefore, it determines the "heat load" by using an easily installed strap-on temperature sensor that monitors the boiler's out-flow water temperature and the rate that this temperature is changing.
Check out our website at: www.energybank.ca
I also post product reviews on my blog: (broken link removed to http://energybank-energybank.blogspot.com/)
Hope this helps!
Have you heard of the Intellicon HW+? It's a microprocessor-controlled, fuel-saving device for hot water (hydronic) heating systems. This unitreduces fuel consumption, wear on parts, flue emissions and electrical usage, when installed on any new or existing gas or oil burner. We have had success providing savings for our customers with these units. We carry the entire Intellidyne product line and this is our 3rd best performing economizer.
Sounds like this product might be your solution as it utilizes a method of "outdoor-air temperature reset control," but does not require an outdoor-air temperature sensor or the need to profile the building in order to adjust the "reset" controller properly. Therefore, it determines the "heat load" by using an easily installed strap-on temperature sensor that monitors the boiler's out-flow water temperature and the rate that this temperature is changing.
Check out our website at: www.energybank.ca
I also post product reviews on my blog: (broken link removed to http://energybank-energybank.blogspot.com/)
Hope this helps!
Another ORC to look at is the HBX Control Systems Inc models. (broken link removed to http://www.hbxcontrols.com/index.php)
I currently have the basic model CPU-500 installed on an 84% boiler and have paid for my purchase within the first year. Very simple to use and the basic model is capable of operating 2 boilers.
I currently have the basic model CPU-500 installed on an 84% boiler and have paid for my purchase within the first year. Very simple to use and the basic model is capable of operating 2 boilers.
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