IGP

It looks like he’s gone for what he’s losing in actual heat loss, making up (and possibly more) with efficiency of the system.

The system is visible on https://heatpumpmonitor.org/system/view?id=139 so make of it what you will but it looks impressive to me.

If you’re going down the rabbit hole of research, this is where I found the most easy to digest information by just going through the back catalogue of the videos in these channels. Completely eye opening. https://youtube.com/@heatgeek?feature=shared https://youtube.com/@urbanplumbers?feature=shared

I'm actually sort of jealous of your blank canvas! If you can get someone to do your floor - think about underfloor heating - this is an enabler for the highest efficiencies in a heating system as its basically the biggest radiator you can have. On heat pumps, if your knowledge comes from reading anything in any newspaper or from the comments at the bottom of articles on heat pumps - forget what you think you know. They don't need highly insulated and leak-free houses, they could heat a barn if designed to do so. Insulation helps make the heat pump you buy smaller and the emitters you need to be smaller, i.e. if i put loft insulation in my home it's heat loss goes from 6.3kW to 3.8kW (obviously already done it) - and it means i can by the 4/5kW heat pump size rather than a 7/8kW. (side note that efficiency can actually be marginally higher on higher heat loss properties, but that isn't a reason not put insulation in, see the graphic below where the 10kW model at 35c is 5.03 vs the 4.48 on the 5kW, but the 5kW is much cheaper to buy) Whilst you could do it with oil and have big radiators and low flow temps - the efficiency gains on oil / gas are in the region of going from 75% to 85% efficiency - so like 10% increase, not nothing. With heat pumps you can be talking multiples. In the example below on a Valliant heat pump, going from 55c flow to 35c there is a increase of 142% on the 5kW model. On your point about being held to ransom by electricity companies - i would argue its almost exactly the same with heating oil companies or whatever. Potentially think about a woodburner as a backup if you're nervous? All I would say is that you need a good engineer - not just any joe bloggs off the street to do a heat pump job - whilst they are actually technically simpler than oil / gas systems - the training across the industry is patchy at best. To find good engineers - look at some of the ones on HeatpumpMonitor.org that are clearly doing great installs. Last thing i'd ask is a simple question - do you think oil heating is the future?

Oh and empty your cavities and fill with EPS beads as described earlier for nice full and even insulated walls. 😃

I recently (over the last year) renovated my house - 1920's semi with 65mm cavity, I had grand plans of insulation everywhere - doing EWI & IWI. Any way, long story short I worked out that loads of insulation is overrated in our climate - law of diminishing returns. 300mm of loft insulation, cavity wall insulation if you can and if you've got suspended timber floors and happen to be doing work there do so. Beyond that, I'd go so far - controversially as saying don't bother. Exceptions would be thermal bridges that would cause condensation. Sort the ventilation strategy. Ultimately insulation doesn't *make* you warmer - it means the space loses heat slower, you still have to heat the space (caveats apply to that broad statement around thermal bridging / uneven insulation across elements) The focus then should be heat pump system designed to the lowest flow temperature you can (<40c) and is weather compensated. This is where you would get the comfort and lower energy bills. Save your money for a well designed heating system.

Can I ask a stupid question - what is your ultimate aim?

HPs are great and can easily be cheaper and more comfortable than gas central heating, but they are different beasts vs gas boilers. They can be a bit of a learning curve as you don’t run them the same way. I would get someone like a heat geek as mentioned earlier to come round, and explain and setup the system in an optimal way for you. It’s just not worth the stress IMHO.

Might be worth taking a look at to see how they did underfloor heating as well. About 5 mins in.

Need, no. But you could for that extra bit of performance.

I would echo the A2A (air con) sentiment. It’s not resistive so doesn’t run glowing hot and will be 2-4 times more efficient than resistive heating. If you’re there for a while, worth it.

This is the kicker, I personally would scrap the BUS but offer 20 year interest free loans to spread the capital cost.

As others have said, something doesn’t sound right to have those kind of bills and still be a bit cold unless you genuinely have an uninsulated mansion.

I'm coming to make peace with hybrids in theory, assuming they are more like the Intergas ones, where they are running for 100% of the heating time, just topped up with heat from the combi rather than stopped and purely running on the combi. Then it's such a marginal step (psychologically) to full ASHP the next time people upgrade their heating / hot water in say 2035 / 2040... I would tier the BUS payment to be say £4/5k rather than the £7.5k for full ASHP installs.

To be fair, a lot of the new HPs have the ‘Quiet Mark’ but that’s nothing official from a regulatory perspective.

Wholeheartedly agree. Same should be with the heat pump, the heat pump itself should be VAT free for whoever buys it, but for all practical purposes (HMRC admin) all the gubbins should only be VAT free if you’re getting as a supply & install job when retrofitting.

Get a heat geek to take a look, they’ll be able to sort the valve but also advise adjust the system to get the best out of it.

I would do your own heat loss, it's not super difficult but for mental bandwidth reasons, perhaps do it once you’ve done the weather compensation bit as @JohnMo described. Knowing that is invaluable and you can start to make very informed decisions without relying on variable quality tradesmen.

Those models have a MID approved meter inbuilt already as I understand it. https://www.ovoenergy.com/heat-pump-plus

What ASHP do you have? If it’s a Valliant Arotherm Plus or a Viessmann Vitocal 15X you can go on OVOs Heat Pump Plus add on which is 15p/kWh for heat pump usage and that doesn’t have any special times so you can run its low, slow and steady for maximum SCoP and a cheap heat pump tariff to boot.

Good thread on it here too, which posted in another thread yesterday. https://energy-stats.uk/vaillant-arotherm-firmware-351-06-07-problems-energy-integral/amp/

Also, what’s the floor situation - concrete or suspended timber? If suspended timber, then there are relatively cheap* insulation opportunities there. Then you get the whole house wrapped up, rather than having a potentially cold floor. *vs digging up a concrete floor

Have you checked your firmware? https://energy-stats.uk/vaillant-arotherm-firmware-351-06-07-problems-energy-integral/amp/

The videos that convinced me were

I’ve got EPS beads retrofitted in my cavity walls. No issues so far. I wouldn’t trust blown fibre, as that can have a tendency to snag on the rough edges inside the cavity and cause clumping and then voids behind the clumps. Then you get cold spots. Beads on the other hand just flow and don’t really care about the rough edges and fill the space. Not only that, they’re not absorbent at all and the spaces allow water to fall through them (eg wind driven rain) and not across them to the internal leaf. Side benefit - it’s much quieter as sound doesn’t bounce around in the cavity. Didn’t realise about that until a few days after retrofit.