Trystan Lea

Maybe less dramatic but there is a risk to undersize on newer build properties, especially where max output during defrost conditions doesn't match datasheet and if build quality is lower than design..

New MCS heat load calculator and EN 12831 I’ve been invited to attend a MCS working group meeting next Monday, discussing among other things heat loss calculation, so this post alongside looking through the new MCS heat demand tool is part of...

I just wrote some more thoughts here on the new MCS heat loss calculator and the ventilation calculation, you may find interesting community.openenergymonitor.org/t/new-mcs-he...

Makes sense in building physics terms but if this just adds to over-inflated heat loss in pre-2000 properties then it's not helping. Key is to have good agreement between calculated and measured heat loss.

Big thanks to TBarton Electrical for doing an excellent job installing the solar and battery system, they've been great to work with tbartonelectrical.co.uk

We will do a detailed comparison

Performance on space heating has been great so far, COP 4. While a buffer was installed as per viessman spec, we also have the option to bypass the buffer and we've been running it with the buffer bypassed all on the primary circulation pumps just fine over recent days 👍

It's been great to be part of this project. While most of the work is credit to Chris from Griffith's heating, Glyn and I did the heatloss calc and are involved in commissioning, optimisation and monitoring of course

That's a great way of approaching it, always good to come at it from both angles, that should be part of standard heat loss calc methodology rather than relying on calculation alone

Thanks Keith, all about a useful amount but not too much , thanks for picking these points up!

When I was getting our heat pump here, because of the twitter heatpump discourse, I was worried that our model was oversized, but found in practice that it actually performs very well! (It's well within @openenergymon.bsky.social's range of useful oversizing).

Heat pumps are running! Still lots of tweaking and tidying to do but building is heating up 😁

30kW SolarEdge PV and 65kWh of GivEnergy Commercial battey system is now up and running, with @openenergymon.bsky.social monitoring 😀

Yes that's correct, weather comp for boilers has not been widely adopted or mandated as is the case elsewhere.

That's a great result! it would be great to see more of an industry push to include weather compensation with boilers , it would help get people more familiar with heatpump controls as well

Thanks James!

Impressive!

4. Our analysis of heat pump max outputs during defrost conditions is available here docs.openenergymonitor.org/heatpumpmoni... and discussion of how much margin is good to add and how to avoid oversizing here docs.openenergymonitor.org/heatpumpmoni...

3. There are risks to accurate heat loss, if your using a design temp of 50C and improving heat loss calc process, consider lowering design flow temps to nearer 40 and add a margin to cover lower than datasheet outputs during defrost conditions docs.openenergymonitor.org/heatpumpmoni...

2. The secret to making design temperatures of 40C (or lower in practice) possible is accurate heat loss calculation and tuned weather comp docs.openenergymonitor.org/heatpumpmoni...

1. Low flow temperatures = high performance (heatpump 101) but did you know high performance heatpump often run at around 34C on the coldest days? docs.openenergymonitor.org/heatpumpmoni...

We've written up the main findings from HeatpumpMonitor.org so far here docs.openenergymonitor.org/heatpumpmoni..., presenting this tomorrow at the DESNZ/IEA heatpump research seminar 🤓

Solar PV install is coming along, only another 43 panels to go! 🥵⚡

I really enjoyed this episode of the @TransitionShow.mastodon.energy.ap.brid.gy podcast with @richardlowes.bsky.social, thanks for the @openenergymon.bsky.social heatpumpmonitor.org mention, "brings an element of fun into heatpumps" 😁

Here's a video about an interesting ASHP installation I was involved with in a solid stone cottage, the combination of insulation, air tightness, UFH and MVHR has made for a very efficient low-cost heating system with a SCOP of 5.1 for space heating 😀 📈 youtu.be/YouOLThHSNk?...

This is part of a big electrification and decarbonisation project for the building to remove deoendancy on LPG, reduce running costs and increase energy security; this will involve 2x 16kW Viessmann ASHP cascade, 69kWh of GivEnergy storage, 30kW of PV and @openenergymon.bsky.social monitoring 😀

More panels going up! Only 60 more to go 😅

I've been helping out on a solar PV installation on our @Openenergymon shared office space, it will be a 30kW SolarEdge array! Today we fitted the rails and got the first couple of panels in place 😁

This Skill Builder heatpump now one of the best performing systems in the country thanks to a Heat Geek transformation! Here's the live and historic data monitored independently by @openenergymon.bsky.social 👏 heatpumpmonitor.org/system/view?...

Big update incoming for OpenVehicles (OVMS) Android app 😍

Interesting podcast about the Electrification Of Heat government heat pump trial results with Katrina Young from @energysyscat.bsky.social and @trystanlea.bsky.social from @openenergymon.bsky.social