ASHP – Should do better - Must Do Better

TiredGeek

Here's a little question about MCS accreditation aimed at those in the know:
If a company just supplies the EcoDans and a set of instructions, leaving the client to carry out the instalation, then simply does a commissioning, does this comply with MCS?

I'm thinking not, but I'd like other opinions on this.....

Cardew

TiredGeek wrote: »

Here's a little question about MCS accreditation aimed at those in the know:
If a company just supplies the EcoDans and a set of instructions, leaving the client to carry out the instalation, then simply does a commissioning, does this comply with MCS?

I'm thinking not, but I'd like other opinions on this.....

Personally I would see no reason why it wouldn't comply. It is just like using a sub-contractor.

A firm employing Gas-Safe engineers would surely be allowed to use apprentices/sub-contractors as long as a Gas-Safe engineer, checked, commissioned and certified the work?

Ditto electricians.

http://www.icsheatpumps.co.uk/blog/mcs-installer-accreditiation/

Re your 'lost £14k, it seems that the limit for the 'Small Claims' court will soon be increasing to £15k

TiredGeek

Thanks for that, we won't use MCS in our arguments then

I doubt we'll be lucky enough to go the the small claims court, it probably won't be retrospective or this will all be over before it changes....

harryhound

muckybutt wrote: »

Now we live in a 1850's terraced with no double glazing as we are listed and cant have it and we have solid walls.

You can get away with fitting this sort of secondary glazing to a listed property as it simply glues to the window frame and no screw holes are drilled into the fabric of our nation's heritage buildings

....and even if some sort of sub frame is needed, who is watching:D

http://www.magneglaze.co.uk/

harryhound

TiredGeek wrote: »

Here's a little question about MCS accreditation aimed at those in the know:
If a company just supplies the EcoDans and a set of instructions, leaving the client to carry out the instalation, then simply does a commissioning, does this comply with MCS?

I'm thinking not, but I'd like other opinions on this.....

I am cautiously edging towards a Heat Pump installation, especially if and when we get the final details of the RHI.

I have a friend in the fortunate position of owning a summer time retreat in the form of an 19th century farm house. He needs to keep the frost out of it, when it is left more or less unattended for 4 months of the year. (it is a "holiday let" in the summer).
He has been targeted by heat pump salesmen.
I think I've persuaded him that better controls on the oil boiler are a more sensible choice, at least for the next few years.

These are my understandings of Heat Pump technology:
Note the point about the MCS process will require a proper SAP study in the not too distant future and this is likely to be combined with proper training for the new user of this "new to us" technology.

http://www.bre.co.uk/sap2009/page.jsp?id=1642


DOMESTIC INSTALLATIONS
Not a simple replacement for 80 degree boiler.
90k btu = 23kWp
Typical HP is 10 kW.

A Calculate the heat losses SAP for internal and external temperatures (-2?)
Approved software will soon be a requirement for MCS certification.
B Improve the house so 10kW will service it. (£300 on insulation = £3000 saved on HP.)
C Heat Pump selection. Aim for 100% heat pump at design temperature not 70%
D Choose back up heating. Log burner?
E DWH ? ? E7 night electric?
F Under floor heat at 35 not radiators at 45.
G Beware of cycling.
H Beware of Zoning.
I 10 mins a week for legionaire.
J 55 degree DHW requires a big tank.
K Inverter control? 12 – 14 kW is the max for single phase.
L Buffer tanks prevent cycling.
M Modern GSHP noise in not an issue. ASHP it still can be
N Thermal mass allows thermostat differentials to be 7 – 8 degrees not 1 – 2


{I am not a guru, so please disagree with me if you think these points are wrong}

Cardew

Harryhound,

These two points of yours are hugely important IMO for some occupants.

Not a simple replacement for 80 degree boiler.
90k btu = 23kWp
Typical HP is 10 kW.

Under floor heat at 35 not radiators at 45.

Gas/oil boilers with their high output can produce very hot water quickly. With water in radiators at up to 80+C there is no need to to have any heating until, say, 20 - 30 minutes before you return to house after work, or indeed get up in the morning. Surely most of us have heating going off for several hours overnight?

With water in underfloor heating at 35C it takes a long time to warm up a house and so you must have the ASHP running for far longer(or even constantly) to come back/wake up to a warm house.

So when considering the COP of a system it should be remembered that the ASHP will be producing heat at times when it wouldn't need to be produced by conventional CH. Put it this way: say 10,000kWh of heat produced by an ASHP is not as effective as 10,000kWh of heat produced by conventional CH as the latter can be used at times when it is required.

A conventional CH system can also have a combi boiler.

TiredGeek

Harryhound, while I'm no expert myself his house is more or less the same as mine when it comes down to it (who's to a hundred years or so ).

First, insulation.
Without losing the character of the house improving the levels of heat retention are very hard. It's not a case of £300, that'll go nowhere in these type of properties, good insulation levels are simply not achievable unless you have a bottomless money pit. I have been told by an architect that 1 metre of stone is only equivilant to 100mm of rockwool which gives you an idea of how bad it is to start with.
You'd have to use either internal wall panels, losing the original plaster/wood finishes, or external insulation which is both expensive and makes the building look modern as the finish is too uniform.
Also, and here's the kicker, the building most likely has no DPC and lime mortar/plaster - cover walls like this with insulation, either inside or out, and you trap damp in there, this leads in the short term to condensation behind the insulation and damp problems, and long term to structural damage as the lime mortar breaks down! (BTW, this also applies to modern cement render, water proof masonary paint, and "stain block" products)
The reason my house isn't done, apart from listing.

Same sort of problems with fitting UFH. Even if he was willing to lose the original floors, digging the old ones out and putting an insulated slab down isn't a simple process in these old places. My foundations go down all of 10 inches, they used to simply strip the grass off and build on the first compacted bit of ground they found. Digging out for the slab can undermine the foundation and cause issues unless GREAT (and expensive) care is taken.

Windows is the other big thing. Lose the original features for better insulation or keep the look that made you buy the house in the first place..... or spend £££££££ geting new old windows made.

You can throw insulation upwards into the roof voids, assuming they have a void of course, but that has a limited effect compared to the loss through the walls and windows. You have to use the right stuff as well, you don't want to be putting 300mm of rockwool onto old ceiling joists, you might not think it weighs much, but just try lifting two rolls together next time you're at B&Q. In a year or two the ceilings will sag, or worse case collapse, they were never designed for that sort of load and now it's old, it's even weaker. Lightweight insulation is far more expensive than rockwool, so that £300 starts to look more like £2k by the time you're done.

Has he got room for a large DHW cylinder? 300 litres minimum I would think as the water is cooler so you don't top up the bath/shower with cold, therefore using more hot, therefore needing more of it in the first place. 300+ litres of water does tend to be heavy, so really you don't want that on a suspended floor, you need it on a solid slab floor so that's downstairs. Has he got a spare 800x800x1800 space for the cylinder that meets the criteria?

Radiators. For frost protection it's not such a big deal, but if you want it to get to 20'c or more then they're gonna have to be BIG in a house like this, or big and many. So you're gonna cover all the available walls with radiators, kind of spoils the look. It can be done with "blower" rads, but they're very expensive in comparison, even though you need fewer of them.

I went for nearly 200% heat capacity with my units, 15kw required (according to SAP) and 28kw fitted. Inverter driven so they can turn themselves down if all that capacity isn't needed. I also had radiators way oversized. It CAN get the house comfortable, but the cost is not good and we had failures during winter. It's getting replaced this summer with LPG until the house isn't a holiday home anymore. When we retire there, we'll look into heat pumps again as then the frost stat won't be an issue.

Tell your friend to keep his money and spend it on oil for the winters, the cost of putting heat pumps in for a holiday home that needs frost protection is both expensive and may not even work!

However, the RHI does throw a spanner in my works.
IF you're gonna get £1k every year for 18 years for having the thing, and IF it works over winter as a frost protection system, then the heating is free in effect. You have to stand the cost of installation, but over say 10 years then the cost of the oil would pay for that and you've had free heating for those years so your no worse off. The next 8 years 'till the RHI runs out then gives you free heating which in effect puts money back in your pocket. If you can get over the frost protection issues I've had then it makes a lot of sense.

Bottom line is this: if you buy an old property be ready for large heating bills. I did and I was, I tried to minimise the bills with heat pump technology, for me it hasn't worked out, for you it might, but be aware of the pitfalls! IF I could get technology that was guaranteed to do ALL I need of it, I'd go heat pump again, but 'till someone gives me a-money-back-if-it-doesn't-work promise, it's gas for me

harryhound

I've not looked into "Lithuanian?" wood chip, because I live in a 1960's style electric bungalow with later additions.
Perhaps that might make sense - I've seen figures that suggest that this country could support a yield of 2 million tons of grown and recycled wood chip. So it is not for everyone. I know a Slovak who gets through 14 tonnes a season in his Eastern European farmhouse.

A house like yours will almost certainly always need "hot" radiators for comfort.

lovesgshp

To Tiredgeek.
In my opinion, a buffer tank should have been fitted at installation, to help stabilise the heating temps and the heat curves could have been reset to make optimum use of the temperature control in the pump.
To oversize is ridiculous, you needed 15 kw output, so you spent another £k? for nothing in terms of performance.
I have stone walls with no insulation, as do most here in Italy.

Cardew

Geotherm wrote: »

To Tiredgeek.
In my opinion, a buffer tank should have been fitted at installation, to help stabilise the heating temps and the heat curves could have been reset to make optimum use of the temperature control in the pump.
To oversize is ridiculous, you needed 15 kw output, so you spent another £k? for nothing in terms of performance.
I have stone walls with no insulation, as do most here in Italy.

Do you fit ASHPs as well as GSHPs?