Hi RV3,

What I would suggest is that you see if you can hire a Thermal Imaging Camera.

Then one cold evening, some time after the Sun has gone down so that there is no solar gain in any of the building fabric, go around your property and take images from every conceivable angle.

This will enable you to see where the greatest heat loss is occurring. This would normally be windows that would show as orange/red in the image, with colder areas as blue/black. If you see any areas of the walls or roof that are lighter than the surrounding area then that would indicate greater heat loss.

You could also try the same indoors with the lights out, where darker areas would indicate colder and hence greater heat loss.

I forgot to ask, do you have double/triple glazing?

How are you for draft proofing?

Regards,

Derek.

@derek-m thanks will look into the thermal imager.

We're double glazed. Need to look into draft proofing - could probably up our game with this one - we ain't passivehaus though that's for sure.  Thanks for the continuing responses.

A lot has been made about insulation, and rightly so. It is such a critical component of having an ASHP. You may want to consider renting a thermal imaging gun that may assist in getting some answers. It's just so frustrating not knowing what's in the walls.

Heat loss and emitter guides are key, and we've been exposed to a whole new level of of experience based on this, and it involves K3 radiators. We're only on our second evening, but I think we've cracked our heating dilemma in the cold rooms. We'll monitor the situation over the next few evenings (luckily we drop to -1C tonight). But K3 rads might be the solution for a lot of ASHP owners that have 'conventional' or K2 rads like we used to have with rooms not coming to temperature.

For us, after a winter of hits and misses, and the recent work we had done, it's all too clear that the system needs to be designed and implemented correctly for each and every home. We're just lucky that we've had a supportive manufacturer on Global Energy Systems that have come up with a solution. 

@rv3, the key is to get the balance right between all moving parts: insulation, radiator sizing, distribution pump for flow and correct ASHP size of property. Did the guys who quoted give you a heat emitter guide and advise on changing on any rads?

@rv3, the double glazing is good. Forgot to ask that. 

Hi RV3,

You can follow this link to a company that hires out Thermal Imaging Cameras.

https://www.red-current.com/thermal-imaging-camera-hire?gclid=Cj0KCQjwyN-DBhCDARIsAFOELTkWNT3agxPgm1JthOFqPO31Um53gd4dNa1kv6bUADjMS-wG6h2saDkaAieVEALw_wcB

To check and plug draughts around your windows you could try:-

Stormguard - Draught Excluder - Secondary Glazing Film

Regards,

Derek.

Deep breath. Nervous fidgety glance around. Quiet voice. Hopes no-one will notice he's posted this because thinks they'll all shout at him: We've pressed go on the 14kw Ecodan ASHP. Yes there are things that aren't ideal re our situation. We'll do what we can re home improvement but we're constrained from the optimum set up. But at the end of the day we have to heat our house and at the moment we do that with LPG. As long as this doesn't cost more to run than LPG - then it'll be cost neutral as with the RHI the install costs work out the same as the new kit we'd need to put current LPG system right. So at least it's a shift to a better energy source.

Hopefully this isn't a massive mistake. As always welcome any perspectives can still swerve if we need to for a couple of weeks yet. So many threads on here have been so useful. In the Ecodan and our MSC accredited installers (and their running cost estimates) we trust............ 

Congratulations and good luck.  The fact that you are coming from LPG will help with the running costs comparison. I'm similar as I came from E7 storage heaters.  For those switching from oil it's a closer comparison and for mains gas it's more of an ethical decision. This might reassure you; some of the unit costs might nead adjusting but you get the idea.

https://nottenergy.com/resources/energy-cost-comparison/

Please keep the forum updated!

@kev-m - thanks for this. Useful - my reading of it is that it backs up our reasoning - hopefully!

Will keep the forum updated - if we're making a big mistake would at least want others to avoid doing the same, and the help from this forum has been excellent. There is a lead in time of approx six weeks so will be a while yet.

@amyfod welcome to the forum. I would suggest getting a few quotes. As questions like “why they have sized this ASHP “ or “why xyz make”. Make sure they are MCS approved. What is your heat loss and heat demand from your assessment?  Does this match the ASHP size?
The mantra is always “fabric first” so insulate as much as possible, to drive down your heat loss & hence demand (hence lower future running costs). If you can go underfloor heat replacement of radiators, again this will pay dividend in the future with lower running costs. This was not an option I had, so I went high temp. Doesn’t mean I can’t lower the output temperature of the ASHP at some future date, but HT gives me options. 
With your radon issue, could a mechanical heat recovery system help?  I’m not technical enough but it could clean your air and reuse the heat. 

@julianc Thank you! Regards the heat loss calculation, the Heating Hub estimated 18,869kwh and the EPC has us at 14,142 kwh. The heating hub says our maximum heat requirement on a very cold day (-2.8 degrees) would be 6.6kw. Using the 100w per m2 rule of thumb I saw somewhere else, with 123.4m2 would put at us about 12,500kwh at the very least. Is that right?

The heating hub said we could go for a 7-8 kw low temp heat pump if we upgraded our radiators, although they recommend a high temp one instead. I don't know if that would be a different kw.

The one quote we have so far is for £14,578 for a Stiebel Eltron WPL 17 ACS ASHP - looks like that's 8 or 9kw? With a 200l hot water cylinder and a 100l buffer tank. That does not include any new radiators. However, the installer is MCS registered and we'll get the necessary cert for the RHI. 

We've got double glazing (although it's probably ten years old), cavity wall insulation and some rubbish loft insulation which we'll upgrade. I'm not sure we can afford/handle the upheaval of under floor heating, but we might consider it. 

I absolutely don't know anything about a heat recovery system. Perhaps that's something I should look into... Thanks for the heads up!

@amyfod the 100W/m2 is just a rule of thumb. So your assessment from MCS accredited installer should give much more detail, so best using that. I was told the Stiebel machine was very good, too end. 100L buffer is large. We have 27L plus the pipe work. But the designer is the expert, so will have sized accordingly. But that’s why I’d get several quotes to compare solutions, prices and, if you are like me, ask dumb questions. I’m good at dumb, ask my wife. 
The Stiebel machine looks like a washing machine with a grill, but is supposed to be v reliable and more expensive. I couldn’t get to the bottom of what the extra cost delivered. So I think your price is high ish. Check out Worcestershire ASHP elsewhere on the forum for details of my installation. 

@amyfod, as @julianc said you should definitiely get more quotes.  Our 14kw ASHP plus 250l cylinder, 12 radiators and all pipework (we had no central heating) was £16.5k. 

Be careful with the 100W/m2 rule of thumb.  It is just that and varies with house construction, insulation, etc. A decently insulated cavity wall house with good loft insulation is likely to be less, especially an end terrace.  If you want to compare figures, our 1990 detached bungalow (the worst shape for heat loss) is 165 m2 external, 127 m2 internal, EPC says 21,000 kWh for heating, survey said 6000w heat loss and we have a 14kW ASHP.

Welcome to the forum and good luck.