Tim Robinson

overall system power output into the house.

this is my theory. So I may need to throttle down the other rads to increase the overall system power. Chatgpt told me i'd not increase overall power. But I think this might have parallels to impedance matching of a transmission line to optimise power. Maybe that's a stretch too far...!

So this has got me thinking. I have a 'big' radiator far away that struggles to get hot and gets far less flow than some much smaller rads that have much lower power dissipation. So if I throttle flow to small rads, to encourage more to BigRad, does the overall system heat output inc or dec?

Yup. We are waiting for my next fix! I've built a low temperature weather compensated system based on Tomas's videos. So far working well..!

In case you missed it ...
We never had a ref to leave the Single Market. So we wouldn't need one to rejoin it. You can be in the Single Market without being in the EU. Leaving the Single Market was therefore a POLITICAL decision made by a previous government. Later governments are not bound by it.

Approx 11C

so that's nearly 1000 litres per hour? Wonder why my flow is only around 660 litres/hour. I'm wondering if my pump is a bit short of oomph, or whether it's just working as designed?

Hey Tom, just looking at your historical data. What unit is the flow rate in? l/s?, m^3/hr? or something else?

Oooh i guess i could stick in a Shelly 1 PM rather than faff with a kWh meter. I will have a rummage through my box of bits!

urgh. That's so annoying....Now I'm going to have to meter the power used by the boiler 🙄 which means installing a kwh meter into my board and adding a feed to my esp32 meter pulse counter.

ok so here's mine. emoncms.org/app/view?nam... I've not got a kwh meter on the boiler electricity supply as I think it's quite negligible compared to the gas usage!

@tomasmcguinness.bsky.social so in preparation for cold weather, the new weather compensation system is now in operation. Just waiting for some cold weather now to see how we get on!

Did I imagine it or are you uploading gas boiler performance stats to openheatpumpmonotor.org?

Ooooh. Videos would be great if you have time.

Are you going to post progress? I'm really interested and wondered if this is something that we should be doing. We'd need to mount our ASHP above our back door I think, so is not a straightforward install. But a very simple pipe run.

Exciting times! Are you doing all the plumbing too?

How Hard Can It Be?

Installing your own heat pump? Sounds exciting. But HHCIB?

I've changed the headings to reflect the values in Watts!

don't have an email for you and I think your DMs are blocked?

that's a typo.

I can send you my spreadsheet which was loosely based on your video if I can DM it?

are we talking deltaT between flow and return, or between av flow temp and room temp?

pump is set to fixed rate.

well i was hoping to simulate a heat pump at DT20. That's clearly not going to work with the heat losses I have calculated.

it's a kind of gut feel at the moment. I did flow rates by turning off all rads measured flow individually. see attached. Wonder if I can use these values for a first stab at balancing by running with the slowest rads open, then gradually open the others by to add 2-3 litres/min to the overall flow?

612 l/h is pretty much the same as I'm getting, whether heating DHW in the tank or heating the house via the rads. Seems quite low :-(

do you have your heat meter connected to your boiler still? I'd be interested in your overall flow rates to your rads when in heating mode?

And its a pretty short pipe run from boiler to HW tank. (Approx 6 or 7 metres of 22mm pipe) So I'm thinking either a faulty pump, or a gunged up pipework? What is your circ rate to HW tank?

Yup
It's a bit of a mystery actually.. according to chatgpt the most power I can transfer at 650 litres per hour with. DeltaT of 11 degrees is about 8.4 kW regardless of actual temp. I'm mystified as to why the pump won't deliver more than 650l/h. The boiler specs indicate it can do twice that.