This video shows how outside temperature changes the heat loss on the property and how weather compensation can be used to balance the loss with the heat input from the heat source.
What a fantastic in depth explanation of weather compensation. You are a natural at these explanations and so on the money technically. Fantastic. I'll be sending your videos to my customers.
great video and clear explanation, thanks. It seems like the best way to get the most from WC is a hot water tank - not a combi? that way you can size the boiler so your modulation can go low enough for average temps, and the lower size of the boiler needed should still be enough to heat a HWC? A combi like we have would need to be sized for instant HW and unlikely to modulate down for low enough flow temps? eg at the moment we’re running at 12-13c outside, heat loss 6kw in the house, we can run at 30c flow temp and the house is lovely and warm, but the boiler still cycles because it can’t maintain 30c. Vitodens 050-w 30kw for HW and I think can modulate down to about 3.2kw? 1:8.
Just subscribed - what a great job you are doing at putting this across in a way that is easier to understand. I really look forward to seeing more presentations from your channel. Out of interest is the spreadsheet you are using available or is it taken from the Cibse guide?
Very informative and helpful information. Are the spreadsheets you show in your videos, custom made or are they a resource we can obtain from the internet or from a paid service?
Great content throughout. The only part I don't understand was 15:03 With an 11Kw boiler and a 16Kw coil, why do you get to condense through 95% of the cylinder heat up? Where does the 95% figure come from and why does 11 into 16 keep things within condensing mode with the return below 55°C?
Most cylinder coils are about 16 ish kw according to the data sheets for domestic cylinders. Due to the coil being bigger than the heat source the boiler doesn’t modulate back because the coil is beyond the saturation point and keeps the return temp lower for longer. 95% is just me testing my set up. A Heat pump or Solar cylinder piped in series would work better due to the coil size.
@@hvaccuffingit6471 thanks. I wasnt sure if boilers would modulate on the DHW side. I'm looking to design a new system for DT5 heat pump ready but if i choose to fit a V 200-w 4 pipe, I'd like a cylinder thats going to reheat quickly. Vaillant unistor is around 16.7kw coil and 1.4kw loss, joule cyclone is 23kw coil but 2kw loss. I'll have to look into heat pump cylinders or a twin coil.
The boiler will modulate back on the return temp closing the delta regardless of what it’s heating. If you have a cold cylinder with a giant coil you’ll hear the fan speed gunning it on the boiler and you’ll even see the flow temp dip as it’s a fantastic heat transfer. As it approaches 60 degrees cylinder temperature the boiler will struggle to dump the heat and modulate right back. Best to get a heat pump cylinder as it will be more efficient on heat up and you are future proofed.
Sorry a silly question: why is my plumber saying tjhat Opentherm is old and is not worth it and wont make difference? I got TADO thermostat supporting it and Ideal Vogue max s18 supporting it yet the electrician and plumber disagree and have no idea how that is support to help because boilers have regulators and do that by itself. Am I loosing my mind?
Opentherm will load compensate the boiler and alter the flow temp depending on outside temperature. Weather compensation from the internet ish. Some controllers are less aggressive than others. The boiler will only modulate itself in most scenarios on a set flow. So if it’s set to 70 and the return is coming back higher than 50 (dt20) it will start to reduce the fan speed and modulate back. Opentherm will be more efficient because you flow will be lower on most days increasing condensing and will work in conjunction with the boiler modulation.
@@hvaccuffingit6471 so, opentherm is highly recommend? Y is it not common in UK,? I want to get PDHW and opentherm, seems like weathercom is not good/effecient? Also not possible to turn it off? Atm struggling to get TADO starter kit connected to IDEAL VOGUEAX S18 via opentherm. Confused
@@bimiuk4051 just looked it up, you should be able to PDHW and use OT or WC on the heating. Urban plumber has done a video on this. Just show your installer that video. You may need to run additional cables though. Good luck.
More cause and effect without a heat loss. You set the curve and see how it corresponds with the set point. If the rads are undersized elsewhere in the building then you’ll not achieve set point there or vice verser.
What a fantastic in depth explanation of weather compensation. You are a natural at these explanations and so on the money technically. Fantastic. I'll be sending your videos to my customers.
Thanks Andrew👍
Only just found your channel. It’s a shame that you don’t seem to be publishing much content as you explain things simply & clearly 👍👍
That’s the best presentation I’ve seen on it. Subscribed 👍🏻
Still liking more load compensation than weather compensation. It's way better for my lifestyle and "comfort".
great video and clear explanation, thanks. It seems like the best way to get the most from WC is a hot water tank - not a combi? that way you can size the boiler so your modulation can go low enough for average temps, and the lower size of the boiler needed should still be enough to heat a HWC? A combi like we have would need to be sized for instant HW and unlikely to modulate down for low enough flow temps? eg at the moment we’re running at 12-13c outside, heat loss 6kw in the house, we can run at 30c flow temp and the house is lovely and warm, but the boiler still cycles because it can’t maintain 30c. Vitodens 050-w 30kw for HW and I think can modulate down to about 3.2kw? 1:8.
Just subscribed - what a great job you are doing at putting this across in a way that is easier to understand. I really look forward to seeing more presentations from your channel.
Out of interest is the spreadsheet you are using available or is it taken from the Cibse guide?
Thanks for the feedback.
I can send you a spread sheet of the heat calculation, I just made them up though.
Very informative and helpful information. Are the spreadsheets you show in your videos, custom made or are they a resource we can obtain from the internet or from a paid service?
I’ve just made them up for the video. =sum(etc etc)😉
Great content throughout. The only part I don't understand was 15:03 With an 11Kw boiler and a 16Kw coil, why do you get to condense through 95% of the cylinder heat up? Where does the 95% figure come from and why does 11 into 16 keep things within condensing mode with the return below 55°C?
Most cylinder coils are about 16 ish kw according to the data sheets for domestic cylinders. Due to the coil being bigger than the heat source the boiler doesn’t modulate back because the coil is beyond the saturation point and keeps the return temp lower for longer. 95% is just me testing my set up. A Heat pump or Solar cylinder piped in series would work better due to the coil size.
@@hvaccuffingit6471 thanks. I wasnt sure if boilers would modulate on the DHW side. I'm looking to design a new system for DT5 heat pump ready but if i choose to fit a V 200-w 4 pipe, I'd like a cylinder thats going to reheat quickly. Vaillant unistor is around 16.7kw coil and 1.4kw loss, joule cyclone is 23kw coil but 2kw loss. I'll have to look into heat pump cylinders or a twin coil.
The boiler will modulate back on the return temp closing the delta regardless of what it’s heating. If you have a cold cylinder with a giant coil you’ll hear the fan speed gunning it on the boiler and you’ll even see the flow temp dip as it’s a fantastic heat transfer. As it approaches 60 degrees cylinder temperature the boiler will struggle to dump the heat and modulate right back. Best to get a heat pump cylinder as it will be more efficient on heat up and you are future proofed.
@@hvaccuffingit6471 👌
Sorry a silly question: why is my plumber saying tjhat Opentherm is old and is not worth it and wont make difference?
I got TADO thermostat supporting it and Ideal Vogue max s18 supporting it yet the electrician and plumber disagree and have no idea how that is support to help because boilers have regulators and do that by itself.
Am I loosing my mind?
Opentherm will load compensate the boiler and alter the flow temp depending on outside temperature. Weather compensation from the internet ish. Some controllers are less aggressive than others.
The boiler will only modulate itself in most scenarios on a set flow. So if it’s set to 70 and the return is coming back higher than 50 (dt20) it will start to reduce the fan speed and modulate back.
Opentherm will be more efficient because you flow will be lower on most days increasing condensing and will work in conjunction with the boiler modulation.
@@hvaccuffingit6471 so, opentherm is highly recommend? Y is it not common in UK,?
I want to get PDHW and opentherm, seems like weathercom is not good/effecient? Also not possible to turn it off?
Atm struggling to get TADO starter kit connected to IDEAL VOGUEAX S18 via opentherm.
Confused
@@bimiuk4051 does that boiler even do opentherm?
@@hvaccuffingit6471 yes from my understanding it does. :( seems Ideal Logic supports it but Vogue max???
@@bimiuk4051 just looked it up, you should be able to PDHW and use OT or WC on the heating. Urban plumber has done a video on this. Just show your installer that video. You may need to run additional cables though. Good luck.
Without heat loss calcs ,it must be guess work .
More cause and effect without a heat loss. You set the curve and see how it corresponds with the set point.
If the rads are undersized elsewhere in the building then you’ll not achieve set point there or vice verser.