small collective heating modification notice
published: 10/12/16, 23:06
Hello,
I am on a big project of renovation of a mill in Franche Comte which has the peculiarity of having a part of the building dedicated to the rental, 8 apartments of 60 m² each all classified C (133kWh ep / m².an) on the DPE (for what that's worth ...) volume to heat with the ladle 1000 m3 (part in roofing)
For the moment we are on an aging oil boiler (we consume with ECS about 6000l / year) but the existing installation does not suit us for 4 reasons:
1 - The presence of a tank of 3000 l fuel in the mill while we are on the banks of the river (the Ognon for those who know) in a flood zone on a porous subsoil (alluvium) makes me flipper, the less fuel leak hello ecological damage ...
2 - The fuel it stinks ... (admittedly purely subjective as opinion)
3 - The heating circuit although it is in parallel is badly done because the pipes are inaccessible (thus impossible to modify easily) or the heating loads are roughly divided by dividing them by 8 which penalizes the tenants responsible relative to the others (not big ones who have the windows open in the winter heating to bottom to clopper without smelling their apartments and they clop up a lot and long, see those who open to ventilate then go on extended weekend forgetting to close while he do -7 at night ... anyway ...)
4 - The fuel it stinks ... (I know I'm repeating myself ...)
So we will change the whole installation this summer, basically:
- We keep the radiators in each apartment but we redo all the plumbing passing the new pipes by the DRC (the apartments are at 1er 2eme and 3eme floor, the DRC is available on the entire surface of the building)
- We change the heating mode by switching to wood (log or pellet) with accumulation.
- we do for each apartment an independent circuit (there is between 2 3 radiator per apartment according to their arrangement but the cumulative power is substantially constant at 2000W per apartment) with a power meter for each apartment (ultrasonic volumetric probe with plug temperature in and out.
- We already have the ECS produced by the boiler room (a balloon of 300l) with an ECS meter per apartment so we keep it, we just change the hot and cold water meters instead to group for each apartment the three cold water meters, DHW, and heating in the same place)
- Keep the heating circuit charge pump (a WILO 25/6 in 1 ") which seems to be sufficient (it is generally in position 2)
So much for the "decor" ...
But at this stage I am in metaphysical questions about the design of the new installation since I have not been on the subject for a long time and that it is not in itself my profession either (heating engineer I mean)
So we go for the moment on the following installation (see "beautiful" drawing, sorry it is in English, a habit with me):
- A wood log or pellet boiler with an output of approximately 35 kW (the fuel boiler is 40 kW in the existing one) with a Wilo Star RS 26/5 charge pump on the return circuit ("Boiler Pump") and a 3-way valve ("Boiler 3 Way Valve") whose role is to keep the return temperature above 50 ° C (the aim being to avoid condensation by raising the boiler to temperature as quickly as possible)
- Two 3000 l storage tanks with a valve system ("V1" and "V2") allowing you to either work on a single tank in mid-season when needs are low ("V1" open "V2" closed) or with the 2 connected in series ("V1" closed "V2" open).
- A distribution circuit (horizontal) which serves the 8 apartments (for the sake of simplification of the diagram the small yellow squares marked "C" represent the probe and meter valves for each apartment, for information we are on diameter 28 on this part with a tapping in 18 for each apartment) with a three-way valve ("Circuit 3 Way Valve") and a Wilo Star RS 26/5 charge pump ("Circuit Pump") on the outgoing circuit, the purpose of the valve is to regulate the flow temperature (heating at a constant temperature of 70 ° C whatever the flow rate, each radiator is already equipped with a thermostatic valve) and a differential valve for the improbable case where all the valves of all the radiators are closed ... 2.5 kg / cm² max (delta between flow pressure and return pressure)
- A circuit to supply the DHW exchanger with a Wilo Star RS 25/2 charge pump ("Hot Water Tank Pump") and a non-return valve ("One Way Valve") to prevent the pump from " Circuit Pump "or" Boiler Pump "is on while the" Hot water Tank Pump "is off, there is reverse circulation which bypasses the storage tanks via the DHW exchanger
At the level of regulations:
Choice of manual valves "V1" and "V2".
For the "Boiler Pump" and its associated three-way valve "Boiler 3 Way Valve":
- If boiler (probable) wood logs the loading is manual thus enslavement of the pump by the temperature of the fumes?
- If pellet boiler (automatic start therefore) servo the boiler and the pump to a temperature sensor on the storage tank with start-up when the last ¼ of the tank falls below 50 ° C?
In all cases, control of the "Boiler 3 Way valve" by measuring the temperature just after the "Boiler Pump"
For the "Circuit Pump" and its associated 3-way valve "Circuit 3-Way Valve", there is a system on the existing installation which starts the pump as soon as it is in winter mode and which controls a 4-way valve (at the place of the three ways provided) depending on the outside temperature (basically make it cold it turns make it hot it stops ... it does not break three legs of a duck either) and the going temperature of the heating circuit, we was simply thinking of keeping the management of the pump in summer / winter mode (roughly manual on / off) and managing the three-way valve by a temperature sensor on the outgoing circuit just after the charge pump to maintain a constant temperature of 70 ° C (high temperature heating ... no choice otherwise you have to change all the radiators in addition and there is no room ...)
For the simple DHW pump start-up as soon as the temperature of the DHW tank sensor (last 1 / 3 of the tank) falls below a certain value (on the scale 60 ° C)
In summer and mid season operating on a single storage tank, the cold period doubles the storage volume by engaging the second balloon in series.
Does the installation seem good to you?
I am on a big project of renovation of a mill in Franche Comte which has the peculiarity of having a part of the building dedicated to the rental, 8 apartments of 60 m² each all classified C (133kWh ep / m².an) on the DPE (for what that's worth ...) volume to heat with the ladle 1000 m3 (part in roofing)
For the moment we are on an aging oil boiler (we consume with ECS about 6000l / year) but the existing installation does not suit us for 4 reasons:
1 - The presence of a tank of 3000 l fuel in the mill while we are on the banks of the river (the Ognon for those who know) in a flood zone on a porous subsoil (alluvium) makes me flipper, the less fuel leak hello ecological damage ...
2 - The fuel it stinks ... (admittedly purely subjective as opinion)
3 - The heating circuit although it is in parallel is badly done because the pipes are inaccessible (thus impossible to modify easily) or the heating loads are roughly divided by dividing them by 8 which penalizes the tenants responsible relative to the others (not big ones who have the windows open in the winter heating to bottom to clopper without smelling their apartments and they clop up a lot and long, see those who open to ventilate then go on extended weekend forgetting to close while he do -7 at night ... anyway ...)
4 - The fuel it stinks ... (I know I'm repeating myself ...)
So we will change the whole installation this summer, basically:
- We keep the radiators in each apartment but we redo all the plumbing passing the new pipes by the DRC (the apartments are at 1er 2eme and 3eme floor, the DRC is available on the entire surface of the building)
- We change the heating mode by switching to wood (log or pellet) with accumulation.
- we do for each apartment an independent circuit (there is between 2 3 radiator per apartment according to their arrangement but the cumulative power is substantially constant at 2000W per apartment) with a power meter for each apartment (ultrasonic volumetric probe with plug temperature in and out.
- We already have the ECS produced by the boiler room (a balloon of 300l) with an ECS meter per apartment so we keep it, we just change the hot and cold water meters instead to group for each apartment the three cold water meters, DHW, and heating in the same place)
- Keep the heating circuit charge pump (a WILO 25/6 in 1 ") which seems to be sufficient (it is generally in position 2)
So much for the "decor" ...
But at this stage I am in metaphysical questions about the design of the new installation since I have not been on the subject for a long time and that it is not in itself my profession either (heating engineer I mean)
So we go for the moment on the following installation (see "beautiful" drawing, sorry it is in English, a habit with me):
- A wood log or pellet boiler with an output of approximately 35 kW (the fuel boiler is 40 kW in the existing one) with a Wilo Star RS 26/5 charge pump on the return circuit ("Boiler Pump") and a 3-way valve ("Boiler 3 Way Valve") whose role is to keep the return temperature above 50 ° C (the aim being to avoid condensation by raising the boiler to temperature as quickly as possible)
- Two 3000 l storage tanks with a valve system ("V1" and "V2") allowing you to either work on a single tank in mid-season when needs are low ("V1" open "V2" closed) or with the 2 connected in series ("V1" closed "V2" open).
- A distribution circuit (horizontal) which serves the 8 apartments (for the sake of simplification of the diagram the small yellow squares marked "C" represent the probe and meter valves for each apartment, for information we are on diameter 28 on this part with a tapping in 18 for each apartment) with a three-way valve ("Circuit 3 Way Valve") and a Wilo Star RS 26/5 charge pump ("Circuit Pump") on the outgoing circuit, the purpose of the valve is to regulate the flow temperature (heating at a constant temperature of 70 ° C whatever the flow rate, each radiator is already equipped with a thermostatic valve) and a differential valve for the improbable case where all the valves of all the radiators are closed ... 2.5 kg / cm² max (delta between flow pressure and return pressure)
- A circuit to supply the DHW exchanger with a Wilo Star RS 25/2 charge pump ("Hot Water Tank Pump") and a non-return valve ("One Way Valve") to prevent the pump from " Circuit Pump "or" Boiler Pump "is on while the" Hot water Tank Pump "is off, there is reverse circulation which bypasses the storage tanks via the DHW exchanger
At the level of regulations:
Choice of manual valves "V1" and "V2".
For the "Boiler Pump" and its associated three-way valve "Boiler 3 Way Valve":
- If boiler (probable) wood logs the loading is manual thus enslavement of the pump by the temperature of the fumes?
- If pellet boiler (automatic start therefore) servo the boiler and the pump to a temperature sensor on the storage tank with start-up when the last ¼ of the tank falls below 50 ° C?
In all cases, control of the "Boiler 3 Way valve" by measuring the temperature just after the "Boiler Pump"
For the "Circuit Pump" and its associated 3-way valve "Circuit 3-Way Valve", there is a system on the existing installation which starts the pump as soon as it is in winter mode and which controls a 4-way valve (at the place of the three ways provided) depending on the outside temperature (basically make it cold it turns make it hot it stops ... it does not break three legs of a duck either) and the going temperature of the heating circuit, we was simply thinking of keeping the management of the pump in summer / winter mode (roughly manual on / off) and managing the three-way valve by a temperature sensor on the outgoing circuit just after the charge pump to maintain a constant temperature of 70 ° C (high temperature heating ... no choice otherwise you have to change all the radiators in addition and there is no room ...)
For the simple DHW pump start-up as soon as the temperature of the DHW tank sensor (last 1 / 3 of the tank) falls below a certain value (on the scale 60 ° C)
In summer and mid season operating on a single storage tank, the cold period doubles the storage volume by engaging the second balloon in series.
Does the installation seem good to you?