Jonesy

Volumizer is item 12 on the return leg

Yep.

Hi, unfortunately no buffer setup. But, I could if I wanted to. The hot water cylinder we have has a 50litre buffer integrated at the bottom of the cylinder. It’s currently plumbed as a volumizer on the returns of the heating and hot water coil at the moment, to make sure the system volume is above 30l at all times. But....I could have it plumbed as a buffer - at extra cost, as we’d need extra circulator pumps on the output of the buffer. Also, not sure if the 50litre buffer is big enough due to the heat demand and size of the ashp

Thanks. Yes, good idea, now’s the time to play with it. Due to be -4degC outside over the next few days, so if 35degC works ok in that, am on to a winner ??

Hi, unfortunately no buffer setup. But, I could if I wanted to. The hot water cylinder we have has a 50litre buffer integrated at the bottom of the cylinder. It’s currently plumbed as a volumizer on the returns of the heating and hot water coil at the moment, to make sure the system volume is above 30l at all times. But....I could have it plumbed as a buffer - at extra cost, as we’d need extra circulator pumps on the output of the buffer. Also, not sure if the 50litre buffer is big enough due to the heat demand and size of the ashp

Hi. Just finished a new build, approx 310m2. heating and hot water is serviced by a 17kw grant aerona 3 ASHP behemoth. UFH downstairs with 150mm pipe spacings and rads 1st floor (9 in total, x2 towel rads and 7 oversized rads for thr bedrooms and landing). Grant did the heat loss calcs and specified the 17kw unit - i have no doubt that it’s perfectly fine on the heating capacity vs demand. The house has been insulated above building regs standard and not a massive amount of glass. Grant sized the ASHP on the basis that the rads upstairs may need a 50degC flow temperature; and that the UFH manifolds should then allow mixing down to 40ish degrees. We have two uponor UFH manifold with pumps, and both are fitted with thermostatic sensing heads. We can set these as high as 60 or as low as 30degC. Currently, I’m experimenting with the flow temp, and have the ASHP pumping out 43degC, with the sensing heads on manifolds both set to 38degC ish. The house is perfectly warm and the rads upstairs come on occassionally. My head says I should be able to get the ASHP flow down to 35degC, but not sure how best to do this. If I set the manifold sensing heads to say 40degC and then set the ASHP flow temp to 35degC, i’m effectively making the sending heads redundant, allowing the lower temp to pump round for longer, the ashpwould have less short cycling and we wouldn’t be wasting energy mixing/controlling down at the manifold? Because we have a big open hallway and stair well, the upstairs is mainly serviced heatwise from the ufh in the hallway in the ground floor, with the stat upstairs occassionally firing up - we have a wireless stat that we move around depending on which room is the coldest. I wish we’d had ufh on the 1st floor also, but hindsight and all that! Any advice greatly appreciated.

Hi. Just finished a new build, approx 310m2. heating and hot water is serviced by a 17kw grant aerona 3 ASHP behemoth. UFH downstairs with 150mm pipe spacings and rads 1st floor (9 in total, x2 towel rads and 7 oversized rads for thr bedrooms and landing). Grant did the heat loss calcs and specified the 17kw unit - i have no doubt that it’s perfectly fine on the heating capacity vs demand. The house has been insulated above building regs standard and not a massive amount of glass. Grant sized the ASHP on the basis that the rads upstairs may need a 50degC flow temperature; and that the UFH manifolds should then allow mixing down to 40ish degrees. We have two uponor UFH manifold with pumps, and both are fitted with thermostatic sensing heads. We can set these as high as 60 or as low as 30degC. Currently, I’m experimenting with the flow temp, and have the ASHP pumping out 43degC, with the sensing heads on manifolds both set to 38degC ish. The house is perfectly warm and the rads upstairs come on occassionally. My head says I should be able to get the ASHP flow down to 35degC, but not sure how best to do this. If I set the manifold sensing heads to say 40degC and then set the ASHP flow temp to 35degC, i’m effectively making the sending heads redundant, allowing the lower temp to pump round for longer, the ashp would have less short cycling and we wouldn’t be wasting energy mixing/controlling down at the manifold? Because we have a big open hallway and stair well, the upstairs is mainly serviced heatwise from the ufh in the hallway in the ground floor, with the stat upstairs occassionally firing up - we have a wireless stat that we move around depending on which room is the coldest. I wish we’d had ufh on the 1st floor also, but hindsight and all that! Any advice greatly appreciated.