Hope you guys understand my poor english.. I am about to automate my heating system wich is a wooden boiler.. The water to the heating elements in the house is today regulated manually with a shuntvalve.. Now i want a motor to control the shunt valve. The water should be a maximum 55 degrees celcius. I was thinking of having one temperatursensor outside and one in the house and let the outside sensor decide the main part of how warm the water to the elements should be my thougt was 40degrees when -30 or more outside and 20degrees when 10degrees outside. This would be a linear function. Then I will have a PI controller with SP wanted indoor temp and PV actual indoortemp the output should be -15 to 15 degrees wich i add to the part from outdoor and the sum will be how warm the water to the elements should be.. Is this a wise setup? Or how should you solve this?
Hope you guys understand my poor english.. I am about to automate my heating system wich is a wooden boiler.. The water to the heating elements in the house is today regulated manually with a shuntvalve.. Now i want a motor to control the shunt valve. The water should be a maximum 55 degrees celcius. I was thinking of having one temperatursensor outside and one in the house and let the outside sensor decide the main part of how warm the water to the elements should be my thougt was 40degrees when -30 or more outside and 20degrees when 10degrees outside. This would be a linear function. Then I will have a PI controller with SP wanted indoor temp and PV actual indoortemp the output should be -15 to 15 degrees wich i add to the part from outdoor and the sum will be how warm the water to the elements should be.. Is this a wise setup? Or how should you solve this?
FIRST Your boiler is fired on wood - NOT - made of wood ?? How are you stoking it? Automatic or by hand?
IF you have automatic stoking I would have the outside temperature adjust the outlet temp of the boiler in the inverse manner you describe - ie colder outside results in higher boiler outlet temp.
I would keep the recirc loop you have and replace the bypass valve with a VFD and use 3phase pump. Then vary pump speed to control loop temp.
If mine and if budget allows I would have each room zoned with individual circ pump and thermosat. These would be supplied off the recirc loop. Kinda pricy and tough if the house is all finished construction. While I am spending all your money I would put in underfloor heat.
Hmm the stoking is made by hand..
This is an old house on the countryside with three floors with three apartments.. And money doesnt grow on trees so..
I've never seen the solution to regulate the pump speed for house warming. All ready solutions you can buy is made of the shuntvalve wich mixes the returning water from the elements with new hot water from the accumulator tanks.. I would like having a similar soulution to this but I want to do it my self. I've read that the ones you buy that have both outside and inside sensors get the main part from the outdoorsensor and the indoorsensor fine tunes the temperature.