Im interested in getting a better grasp of how well the monitored maximum output of different heat pumps match their datasheet rated outputs at various outside conditions. In particular heavy defrost conditions. I want to know how much margin is a good idea to build into the sizing assumptions to a…

What was the maximum sustained electrical input during this period? 1600W?

Yes about that 1566W here’s the test run link Emoncms - app view dashboard

It’s a great way of testing emitter spec, I set the flow temp on the heatpump to 55C fixed target, it obviously couldnt get close to that as the heatpump limits the output, I think it software limited at that point… Compressor should go up to 2.34kw I think according to datasheet , but ecodans softw…

[image] ASHP sizing for Freezing Conditions Heatpump [image] I was hoping my Daikin would perform better this Winter with a full suite of well sized radiators and set up sorted out but I was disabused yesterday when it cycled as rapidly as it has ever done. … and just at…

Test 2 Outside temperature back of unit: 3.1C (rising to 3.7C during the max output period) Metoffice outside temperature: 3.1C Metoffice dew point: 2.0C Metoffice relative humidity: 94% I started this test setting fixed flow temp to 50C but the heat pump capped out at 4kW (5:30-8:30pm). I rememb…

Another test this morning, a period of about 1h20 so a bit shorter, but similar average heat output, slightly lower COP: [image] again in the range of what the datasheet suggests [image]

Test 3 Outside temperature back of the unit 0.84C Metoffice: 0.7C Metoffice dew point: -1.3C Metoffice relative humidity: 87% Average heat output 4.57 kW [image] The datasheet suggests that capacity should be 5 kW at 2C ambient and 4.5 kW at -7, so about 4.94 kW at 0.84C. So ~7.5% less than the…

These are the heat input, defrost cooling and net heat values for the last set of tests in the post above Cycle 1: Heat: 4.326 kWh, Cool: 0.182 kWh (4.2%), Net: 4.143 kWh Cycle 2: Heat: 4.484 kWh, Cool: 0.216 kWh (4.8%), Net: 4.268 kWh Cycle 3: Heat: 5.278 kWh, Cool: 0.216 kWh (4.1%), Net: 5.062 k…

Another two max output cycles for good measure: Outside temp: -0.33 Metoffice: -0.1C Metoffice dewpoint: -2.1C Metoffice relative humidity: 87.4% Average heat output: 4.52 kW [image] Heat: 10.533 kWh, Cool: 0.387 kWh (3.7%), Net: 10.146 kWh 1st cycle, 4.53kW (-0.14C), Heat: 5.600 kWh, Cool: …

5kW R410a Ecodan PUHZ-W50VHA2(-BS) maximum output testing

Hardware Heatpump

ColinS (Colin Smith) 26 November 2023 18:53 5

If it helps - I put some data on another thread for the last 24hrs from a selection of heat pumps showing rapid defrosting…some similarities in min cycle time across three brands…