MCS calculations are sh1t

[BotusBuild]

I just had a document from the people processing my BUS grant, which of course means I have to have the design done under MCS guidelines .

 

Their summary of running costs has come out at £2677 per year !!!! WTAF?

 

FYI - House is Jackon insulation slab foundation, Nudura walls, triple glazed windows, warm roof, good air tightness with MVHR, and about 270 sq m.

 

Oh, and the MCS calcs want to put in a 9kW ASHP when even the installer says 6kW would be more than enough.

 

This MCS sh1t has got to stop!!

[JohnMo]

Have given them the air test certificate to fix the high MCS air change rates?

 

Then when they say you can't take credit for MVHR your heat loss actually reduces.

[ReedRichards]

2 hours ago, BotusBuild said:

Their summary of running costs has come out at £2677 per year !!!!

 

This must be based on a price per kWh of electricity, an annual requirement for heating and hot water in kWh and an SCOP for heating and for hot water.  You'll gain more insight if you break this down into these numbers.

[MikeSharp01]

All the suppliers we have spoken 2 over specified the ASHP size. I argued with them all, only two of them listened and reworked it based on the design, and as built, data. Hopefully we are now closing on a deal.

[Roger440]

3 hours ago, BotusBuild said:

I just had a document from the people processing my BUS grant, which of course means I have to have the design done under MCS guidelines .

 

Their summary of running costs has come out at £2677 per year !!!! WTAF?

 

FYI - House is Jackon insulation slab foundation, Nudura walls, triple glazed windows, warm roof, good air tightness with MVHR, and about 270 sq m.

 

Oh, and the MCS calcs want to put in a 9kW ASHP when even the installer says 6kW would be more than enough.

 

This MCS sh1t has got to stop!!

 

Insanity

 

Im in a stone cottage with an extension, the EPC is an E, and its costing £1700 a year in oil at 20 degrees all day and 16 overnight.

 

MCS? Nothing to add beyond what we all know.

 

[marshian]

3 hours ago, BotusBuild said:

Their summary of running costs has come out at £2677 per year !!!! WTAF?

 

FYI - House is Jackon insulation slab foundation, Nudura walls, triple glazed windows, warm roof, good air tightness with MVHR, and about 270 sq m.

 

Oh, and the MCS calcs want to put in a 9kW ASHP when even the installer says 6kW would be more than enough.

 

This MCS sh1t has got to stop!!

 

Your house is over twice the sq m. of mine....

 

My House has

75mm of insulation under the suspended wooden ground floor,

Double glazed windows, Back door and front door all from 1994 (The two double french doors are from 2019 and are to modern stds)

Brick external skin construction, breeze block inner with a 50mm cavity filled with blown insulation

Cold roof and just 100 mm of loft insulation

PIV unit with a heater (not used) not MVHR

Heat loss calculated is 4700 w at -2.4 deg C outside with an internal temp of 20 Deg C

 

Annual Gas consumption for CH and HW is 8900 kWh and Electric is 3500 kWh (No electric heating) so annual total cost for both is £1644 at current rates

£2677 doesn't sound bad but I bet your heat loss calc is less but the bigger the property the more heat will be lost

 

The issue for me is MCS approved suppliers do not want to end upcoming back to fit a bigger ASHP when the house doesn't reach target temp and they aren't going to be the ones paying the bills for the running costs................ As a result they oversize

[joth]

9kW is not a bad size if you have 4 people in there demanding long hot showers and repaid uvc reheat times. 

But for space heating it's almost certainly sized on some pessimistic ACH and insulation levels, plus a bit. 

[BotusBuild]

Thanks for reading and all your replies. I just needed to offload my frustration.

I had delved into the numbers, and I know what they have come up with is cr4p, but this is the only way you can get the BUS, unless you can find someone to "bend the rules" in your favour, and I have spent far too long trying to find a reasonably priced ASHP/HWC solution. I am going with what has been spec'd and then I will tweak it all myself once they have (expletive deleted) off my land. If we end up spending any more that £1000 on heating/HW I will be p1553d off.

 

Heads up for anyone reading this in the distant future. I hope things have changed (but I doubt it). If you can DIY, then JFDI (just ** do it), it'll be cheaper and you'll get a reasonable sized system.

 

 

[ProDave]

And what price has MCS quoted you?  Have you looked instead at just buying a heat pump and your plumber and electrician fitting it?

 

Assuming it is a new house what does the SAP say about heating requirements?

[Bramco]

15 hours ago, BotusBuild said:

Their summary of running costs has come out at £2677 per year !!!! WTAF?

 

FYI - House is Jackon insulation slab foundation, Nudura walls, triple glazed windows, warm roof, good air tightness with MVHR, and about 270 sq m.

 

Oh, and the MCS calcs want to put in a 9kW ASHP when even the installer says 6kW would be more than enough.

 

Our house is similar size 250m2 - MCS insulated slab with UFH, timber frame, triple glazed, v good airtightness, MVHR, warm roof. All electric, it cost us £45/month last year for all electricity imported. That's hot water, heating, everything.  But we do have 6.kWp of solar and 15kW of battery storage and we're on Oct Int G0, so try (successfully most of the time) to only use the 7p rate.

 

We had the ASHP installed on the old BUS grant of £5k. It's a Cool Energy unit, similar to this one -> https://coolenergyshop.com/collections/air-source-heat-pumps/products/cool-energy-invertech-high-temp-air-source-heat-pump-ce-ivt9-evi   so 9kW. Total cost to us, installed was £250 but we already had the cylinders in place for UFH buffer and DHW tank. We had a heat loss analysis from an M+E engineer and Cool Energy were more than happy to use this for the MCS calculations.

 

Unless it's really cold outside, we only run the ASHP at night on the 7p rate - we don't use it for DHW, only for heating. This works fine and even on really cold days, if the sun shines (we get plenty of solar gain) then we don't need to boost the heating during the day. So 9kWs is fine for a house like ours and I'm guessing yours.

 

Have a look at this deal -> https://coolenergyshop.com/collections/air-source-heat-pumps/products/free-heat-pump-kit-for-self-builds-renovations.  You get all the kit for free if you qualify for the BUS grant.  I wonder if you completed the heat loss spreadsheet that's on the forum and provided proof of the U values of your wall and windows etc, whether they would accept these in place of doing the heat loss calcs themselves - they're a small outfit, so it might be worth a try.

 

[JohnMo]

3 hours ago, ProDave said:

price has MCS quoted you?  Have you looked instead at just buying a heat pump and your plumber and electrician fitting it

Have you looked at the MCS scheme where you get to choose (to certain extent) and install. Umbrella scheme is what to look for. Cool Energy do it and many others. They design, supply the kit of parts to you, up to you it's installed and they commission. 

[JohnMo]

The other thing to think about is the heating system - UFH is very forgiving on heat source size as long as you set the flow temperature correctly. Our 3kW heat loss house, has a 28kW boiler I use in cold weather, it will run at min load for hours without stopping. Nice average zero degree day, boiler stopped with housecat 20.7, currently 20.9 (snowing all morning so no solar gains), boiler last ran 6 hrs ago, starting and stopping once overall.

 

As @Bramco shows, batch charging on time of use tariff is the way to go. My 6kW is too small to do it successfully so I just use the boiler, until I get a smart meter that works.

[ProDave]

2 hours ago, Bramco said:

 

Have a look at this deal -> https://coolenergyshop.com/collections/air-source-heat-pumps/products/free-heat-pump-kit-for-self-builds-renovations.  You get all the kit for free if you qualify for the BUS grant.

Thanks,not seen that sort of offer before.

 

All the kit and paperwork for free and you just pay your plumber and electrician to connect it all.

 

Surely for a self builder that has to be the best way to avoid the sort of silly prices a lot are being quoted?

[Marvin]

33 minutes ago, JohnMo said:

Have you looked at the MCS scheme where you get to choose (to certain extent) and install. Umbrella scheme is what to look for. Cool Energy do it and many others. They design, supply the kit of parts to you, up to you it's installed and they commission. 

This is what I did! They were very helpful.

 

 

[Beelbeebub]

1 hour ago, JohnMo said:

Have you looked at the MCS scheme where you get to choose (to certain extent) and install. Umbrella scheme is what to look for. Cool Energy do it and many others. They design, supply the kit of parts to you, up to you it's installed and they commission. 

That is interesting!

 

Quite an innovative idea.

[Bramco]

1 hour ago, Marvin said:

This is what I did! They were very helpful.

 

Marvin, have you written this up - might be very useful for anyone just embarking on the ASHP/MCS BUS thing.

 

I'm guessing it's not that widely known about.

[Marvin]

25 minutes ago, Bramco said:

Marvin, have you written this up - might be very useful for anyone just embarking on the ASHP/MCS BUS thing.

 

I'm guessing it's not that widely known about.

Hi @Bramco. No.

 

I actually installed with the same company this way when there was another government scheme going on in 2021. I carefully checked the MCS regulations about positioning and read up lots of things here, completed the installation and they came all the way to the Isle of Wight to inspect and commission. 

 

Edited Tuesday at 14:28 by Marvin

[Bramco]

@Marvin

 

We had them do the install and obviously the BUS application - this was in 2023 under the £5k scheme.

 

If I'd known they would supply and then inspect and commission, I think we'd have gone down that route as well.

 

We had a few issues but all in all v pleased (touch wood as it's winter!) with the HP.

[BotusBuild]

9 hours ago, Bramco said:

I wonder if you completed the heat loss spreadsheet that's on the forum and provided proof of the U values of your wall and windows etc, whether they would accept these in place of doing the heat loss calcs themselves

Tried this, but they all have to use the MCS calculation guide

[BotusBuild]

To answer some of the other feedback and questions

 

My plumber and electrician are fitting the kit, that is being supplied by Unitherm, who themselves are the MCS umbrella company, like Cool Energy. They are charging £1000 for the MCS side of things - this was all part and parcel of the quote from my plumber.

My preliminary SAP report gave a 79C (laughable) and used MVHR and a Mitsi 8.5kW as the ASHP, and a flow temperature of "Normal (>45C)" 🙂 

 

Now, I have had an interesting couple of conversations over the last 24 hours, and it turns out that what I have been saying to the plumber, who agrees with me (and the forum heat loss calculator) has obviously been taken on board by Unitherm and they have specified a 7kW ASHP, (not the 9kW that I was originally told), and a 250 ltr HWC has not been agreed. It's being shipped tomorrow, ready for installation next week.

 

All told, this is going to cost us about £4,000 after the grant comes back to us.

[mk1_man]

Hi Botusbuild, sounds like you have things sorted now.  I installed by Vaillant 7kW and 250l cylinder myself under an umbrella MCS company.  I already had underfloor installed (previously on gas)  the headline costs were £4k for Vaillant heatpump, £1k for cylinder and £1600 for MCS wrapper so as to access BUS grant.  Appreciate not everyone would want to get there hands dirty but I found it really simple and enjoyable and even with all the associated bits and pieces managed to be cost neutral with £7.5k BUS. 

 

Running costs have been great at less than £2 per day for the whole house (Nov / Dec) I am on Tomato Energy now at 5p / kWh (with 30kWh batteries)  - 250 m2 house similar spec to yours.

 

The MCS Umbrella company I used was www.air2heat.co.uk  

[andyj007]

MCS has to be the most corrupt unprofessional  organisation to be introduced into the building industry ..    

 

Edited 16 hours ago by andyj007

[JohnMo]

1 hour ago, andyj007 said:

MCS has to be the most corrupt unprofessional  organisation to be introduced into the building industry ..    

 

Think that may be going a little to far. They are a for profit organisation that has the ear of the government, and the government has allowed them to put their own stamp within a legal frameworks. It doesn't make them corrupt, it just makes the government foolish misguided and really not fit for purpose.

 

The basics for heat pump selection isn't a million miles away for 99% of the housing stock, which leaks air, isn't well insulated, or constructed that well.

 

BUS grants are a different department, different rules and story. Installers under that scheme may well in the general, be hard working tradesmen, let down and painted with the same brush as the crooks trying to make as profit as possible, until the gravy train stops. 

 

Every insulation should be reviewed for completeness, function and all costs by install company should be reviewed, audited routinely. But over decades successive governments have smashed manpower etc. there is no-one do do all this auditing!

 

I say scrap the BUS scheme, let the market sort it's self out. Set some basic rules that allow permitted development rights for all installations, that aren't stupid

 

[Beelbeebub]

Waving the flag again for the £7,500 grant money to be used for a subsidy on the heatpump electricity used to ensure it never costs more than a gas boiler and any savings below that are paid directly to the home owner.

 

Or maybe (brainstorming a bit) any savings are split between owner and registered installer.

 

So installer puts system in. If the electricity used costs more than the gas that would have been used the subsidy pot pays the difference.  If the electricity used is less than the gas (ie the scop is better than about 3.5) the difference is split between home owner and installer until the pot is spent.

 

Then let the market decide

[Alan Ambrose]

>>> It doesn't make them corrupt

 

Well they have a legal monopoly and refuse to be transparent about how their calculations are done, both of which are unforgivable in my book. The government should know better.

 

Let the SAP & HP calculations be transparent and published as open source so that other competitors can get in on the act. And all the calcs need a thorough review and revamp.

 

>>> They are a for profit organisation

 

My 5 mins of research suggests that all their profits (well those that don't go in director's fees) go to the MCS charity.