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PeterW

Cheap 6KW ASHP

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They've had those for a while, I think it's the Lailey & Coates unit, looking at the colour and controller

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8 hours ago, dpmiller said:

They've had those for a while, I think it's the Lailey & Coates unit, looking at the colour and controller

Are they any good?

They website claims (used to, seems to be under construction at the moment) they are better in the British climate (whatever that is).

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They look OK.  The spec needs careful reading, as the very high COP being quoted is for dry air with a 35 deg C flow temperature.  Increase the flow temperature to 55 deg C for hot water and the COP decreases a lot, as expected.  One nice feature (if it's true!) is that the defrost system has been specifically designed for the problematic UK weather conditions around 0 deg C and just above, which is something none of the other companies seem to mention.  I know, from practical testing, that that the Carrier unit I have (badged by several other manufacturers) doesn't behave well when asked to deliver a high flow temperature during the temperature/humidity conditions that are critical for ice forming on the evaporator.  My guess is that they may well have increased the evaporator capacity, maybe tweaked the fan flow rates and maybe built in a bit more intelligence to the defrost cycle.  That's pretty good, as defrost cycling is not included in the standard COP measurement, and does have a big impact on overall efficiency.

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1 hour ago, JSHarris said:

 My guess is that they may well have increased the evaporator capacity, maybe tweaked the fan flow rates and maybe built in a bit more intelligence to the defrost cycle.  

 

From memory (I looked into these guys about 3 years ago) they use an oversized evaporator. Not sure about the other two things.

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On 03/12/2017 at 00:24, PeterW said:

Here... 6KW Monobloc

Well @PeterW i expect in the next few days a big green parcel will be arriving on my doorstep. I have been looking and reading stuff on here  for ages about ashp in a “i wonder if this would be a good idea” kind of way.... well that part is over and now the next few months will be about designing a system that will work for me. I will be asking for lots of HELP with my plans. 

This unit will be for my refurb project in the cottage, for good help i geuss i will need to generate some key information for my would be advisors..... could you please help me get my list right so that i can get all the information together and in order.  Would it be something like

 

Space heating requirements 

Current room and house insulation levels

size of rooms / house

 

my main aim would be to use this for room heating only on a new radiator system. 

Happy with electric shower 

Instant elecrtic hot water heaters  for bathroom and kitchen sink 

Thanks in advance with list help. 

 

 

 

 

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On 5 December 2017 at 22:20, Cpd said:

my main aim would be to use this for room heating only on a new radiator system. 

Happy with electric shower 

Instant elecrtic hot water heaters  for bathroom and kitchen sink 

Why no ashp UVC ? 

Seems a no brainer, is it a space issue?

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@Nickfromwales just spent the two hours going over old threads trying to get my head around it before responding but i am going to need more time before i can answer you with confidence.....  the ashp will be potentially positioned on a west facing wall at the back of the house, directly on the other side of that wall is a a potentially usable  space below the stairs that are in an open plan kitchen, so depending on the size of UVC  it could be located in this location. (I still need to fully understand how a ashp and uvc works in this system)The whole house is only 10x5 meters, one shower and wash hand basin upstairs and a washing up sink in the kitchen are the only hot water requirments. I would like to heat the two bedrooms and the upstairs bathroom with raidiators designed to run of the ashp.

 

Space heating downstairs is probably going to be done by a combination of electric and a room sealed stove as its a full open plan  area 10x5 and due to feature stone and wood work in the walls its got large uninsulated  sections of wall that i  believe would make heating downstairs with the ashp a waste of time.  

 

My thinking was that instant electric hot water to the shower, wash hand basin and kitchen sink would be cheeper than trying to store hot water and then bring it up to temp with and electric emersion. In the house we live in we have pumped electric triton shower with a little triton 3kw hot water heater above the sink and another above the kitchen sink. We never put the immersion on unless there is need for a luxury bath.     

 

I want to get the cottage heating and dhw system corect while i have the place gutted so am all ears and willing to learn. 

 

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@Cpd

Ok. Some observations ;)

Why bother with an ASHP at all ? If it's only running a couple rads upstairs you'll be far better off going all electric. If you do go for the ASHP I'd deffo be utilising it to provide 100% of the space heating and at the least preheat ( via a small buffer with DHW coil )  for the electric instants. That all takes room and capital, and I assume you want a reasonable cost vs return. 

This sounds increasingly complex and TBH just screams gas combi boiler very very loudly. Can't recall if you have mains gas or not ?

Also, a room sealed stove is a nice feature but kind of mucks up your airtighthess for effective use of the mvhr. I'd go 'outside air fed' for that at the very least. 

For soace hesting with a ASHP you'll need oversized radiators to run at the lower flow temp, you don't really want to exceed 40oC or you'll end up defrosting on grid electricity and a higher flow temp will drop the CoP so you'll also be burning more grid electricity to reinforce the ASHP operation. 

You may be happy with an instant wall-wart over sink water heater but renting a house with one ? It'll look less than appealing and the flow rates from them is pitiful on a good day 👎

 

Before i go on to make some suggestions can you clarify.....

1) gas yes/no ?

2) are you holding onto BOTH properties for the forceable future eg 15+ years?  

3) can you get large radiators in downstairs?

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@Nickfromwales thanks for you observations its what i am after. I am writing a responce with all the answers but it takes me a little time as this is not my  forte....

 

 

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Take your time, it's not a race 😎

I / we put a lot into one post as I am posting between merchants visits / working etc 😉

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28 minutes ago, Nickfromwales said:

Why bother with an ASHP at all ? If it's only running a couple rads upstairs you'll be far better off going all electric. If you do go for the ASHP I'd deffo be utilising it to provide 100% of the space heating and at the least preheat ( via a small buffer with DHW coil )  for the electric instants. That all takes room and capital, and I assume you want a reasonable cost vs return. 

Lack of understanding probably about the ability of this heat pump, it was an ebay buy with the usual buy now and hope i can get it to work for my situation...... i know i can just hear the collective groan  but i have a streak in me that can only be explained as i am a “risk taker” i try to always make calculated and informed decisions but every now and then i just jump without really looking...... having a family has at least stopped me from free climbing and a whole bunch of other reckless activities.    

 

Now i have the heat pump and a mvhr unit so by hook or by crook i really WANT to make them work for me. So as always please be patient. I am not looking specifically for a reasonable cost vs  return, this is a for life property no two ways about it, i have already lived here since i was in my early twenty's but worked away or lived abroad for over a decade. I am back to stay

 

1 hour ago, Nickfromwales said:

This sounds increasingly complex and TBH just screams gas combi boiler very very loudly. Can't recall if you have mains gas or not ?

No Gass, its a small island with a public vehicle exclusion policy, really is a PITA to even get a sparky to come as limited ferries and cost prohibitive.  

 

1 hour ago, Nickfromwales said:

Also, a room sealed stove is a nice feature but kind of mucks up your airtighthess for effective use of the mvhr. I'd go 'outside air fed' for that at the very least. 

Yes if i can get the heating sorted out with the ashp then the wood stove could be a nice feature for geusts and the cave man desire.

I have already got a pipe under the outside gable wall to the fire place (put it in when i was excavating the old fire place to repoint and replace some burnt/ damaged stones) 

i had considered not bothering with a new stove but geusts up until now love it and say it would be a real shame to loose it. 

1 hour ago, Nickfromwales said:

For soace hesting with a ASHP you'll need oversized radiators to run at the lower flow temp, you don't really want to exceed 40oC or you'll end up defrosting on grid electricity and a higher flow temp will drop the CoP so you'll also be burning more grid electricity to reinforce the ASHP operation. 

Understood, as time goes on and i get all the information together i hope that we can design a system that maximises the use of the ashp but does not overwork it.

Am not going to rush into buying anything elts i promise, but have been following other threads and reserching about the right sort of radiators to use with ashp.

1 hour ago, Nickfromwales said:

You may be happy with an instant wall-wart over sink water heater but renting a house with one ? It'll look less than appealing and the flow rates from them is pitiful on a good day 👎

I compleatly agree with you, i am not happy with the wall-warts but as i am trying to spend as little as possible on this house they are sufficient for our needs, but after thinking about it you are totally correct and  they would not be acceptable in a holiday let full stop.  

 

Mr Smarts our in house super talented all rounder volunteer  and computer genius is working on some heat loss calculations and spread sheets that i hope to soon be able to share with  you so that total heat requirments etc can be seen, then the nuts and bolts can be designed around this......  

 

1 hour ago, Nickfromwales said:

can you get large radiators in downstairs?

Yes plenty of room downstairs. 

 

Ok as i said i am totally committed and ready to listen carfully.  Space wise there is all the area under the stairs and the abillity to plum anywhere round the inside  perimeter of the building both upstairs and downstairs. The only available space upstairs is on the landing / hallway by the upstairs back fire exit where i intended to put a laundry cupboard. There is a small false roof at the very top of the roof to hide future mvhr pipework.

 

The realisation of the possibility that i can use the heat  pump for both upstairs and down will provide me with the determination to adress the cold feature walls, ie. just get on and insulate them... but thats another story.   

 

Cottage on the left of the photo and main house on the right

62E48673-4089-4C39-8002-6991BE1BE574.jpeg

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Ok, happy days. If I seem 💯 mph it's because I am ;)

 

Good that you can fit large radiators in, as that'll work well with the ASHP. The bigger the better and that'll allow the flow temp for heating to stay low. 

 

Good that the stove air supply comes from outside, just make sure the stove is airtight as possible / good door seal etc.

 

The reason I asked about how long your keeping it / how close is it was that I was going to suggest a single communal system which would reside at the main dwelling and feed the cottage via an umbilical supply trench. That's out the window as your too far away. 

 

Your having mvhr, so get the place as airtight as a drum. Hire / borrow a smoke machine and do a blower test. You can watch where the smoke goes and just keep going around until you've got it as good as you can. Using a torch outside on a still evening will show smoke outside. 

Also, be VERY mindful of where the intake for the mvhr is placed, as @JSHarris has had recent issues with neighbours wood burners stinking his house out. ;)  

 

More on DHW in a bit. 

  

Edited by Nickfromwales

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11 minutes ago, Nickfromwales said:

Your having mvhr, so get the place as airtight as a drum. Hire / borrow a smoke machine and do a blower test. You can watch where the smoke goes and just keep going around until you've got it as good as you can. Using a torch outside on a still evening will show smoke outside. 

Also, be VERY mindful of where the intake for the mvhr is placed, as @JSHarris has had recent issues with neighbours wood burners stinking his house out. ;)  

 

I am a total nut job when it comes to insulating and airtightness, and never ever rush the detailing, we are a ways of from smoke testing but when the time comes i will be ready. 

Yes i have been following that thread and many others very closely and learning all the time.  My nearest smoke producing neighbors upwind of me are 5 miles away and a lot of open sea between us. Downwind from me they are about a mile away and there are hills and forests between us. So we are all good on that front. 

 

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14 hours ago, Cpd said:

No Gass, its a small island with a public vehicle exclusion policy, really is a PITA to even get a sparky to come as limited ferries and cost prohibitive.  

 

Does that actually mean a private vehicle exclusion policy? O.o I trust the Public Officials do not get Zils B| .

 

More seriously, it screams "work with neighbours / friends and call a sparky for a full day on a time and materials basis to do 2-3 jobs". 

 

Very low overhead to organise on a small scale / ad-hoc basis, a bit more if you set you set up something more semi-official / organised such as a sparky reserving a day a month, booked from the Island Office. Emergencies are something else, of course.

 

Ferdinand

 

Edited by Ferdinand

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Having thermally renovated a smaller detached cottage (4m x 8m outside dimensions, the roof has 7 rows of pantiles on each side) with half brick and 9" solid walls over a period with a tenant in situ, the biggest differences were (no particular order).

 

1 - Lots of loft insulation.

2 - Decent double glazing and doors.

3 - Cumulative effect of boarding out most walls / insulating floors as much as practical. A little difficult with semi-rooms in the roof.

 

We have managed to reduce energy bills by something over half from what they were (still £100 a month, though) despite a 40% increase in floor area, but the interesting thing is that the T's perception has changed from "warm upstairs, cold downstairs" to the opposite - even though it is all warmer.

 

Can I suggest a very careful look at EWI, even if DIY and just for the walls, and a also for underfloor insulation - even if it means a floating floor and a small step.

 

Ferdinand

 

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12 hours ago, Ferdinand said:

Does that actually mean a private vehicle exclusion policy? O.o I trust the Public Officials do not get Zils B| .

Yes i meant general public, A Public official still comes round once a year on a donkey  to collect one child and six goats for rent so all good on that front. 

12 hours ago, Ferdinand said:

Very low overhead to organise on a small scale / ad-hoc basis, a bit more if you set you set up something more semi-official / organised such as a sparky reserving a day a month, booked from the Island Office.

The usual way is to wait for someone to be having work done and then get the trade to fit you in around that job

We are lucky that its a small but strong community and we rally together should there be an emergency

12 hours ago, Ferdinand said:

More seriously, it screams "work with neighbours / friends and call a sparky for a full day on a time and materials basis to do 2-3 jobs". 

This is how we do it 👍

12 hours ago, Ferdinand said:

1 - Lots of loft insulation.

2 - Decent double glazing and doors.

3 - Cumulative effect of boarding out most walls / insulating floors as much as practical. A little difficult with semi-rooms in the roof.

1. The pitched roof in the rooms in roof are at 0.15 W/m²K (this is just from a calotex calculator) 

2. There is considerable scope to improve the doors......  velux windows upstairs and doule glazed hardwood sash downstairs.  

3. The upstairs walls are 0.21 W/m²K (calotex calculator) ground floor 0.21 W/m²K

The area i need to address is the stone walls downstairs, stripped back, repointed and painted white to brighten the place up, its been fine as a summer house but for us to live in it over winter and to get the most out of the heat pump i will need to re do the studwork and insulate with rigid insulation rather than the origanal bit of rock wool stuffed in hear and there.  

Mr Smarts has put together a heat loss spreadsheet but i was wondering if  @JSHarris or @PeterW or anyone on here had one that was better as a template before i venture out information that may be better presented.  As always thanks. 

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@JSHarris has a really good one on his blog. I’ve got a simplified version but I’ve got to say the one Jeremy has is better and more accurate. 

 

Your options on walls are varied but I would really look at that floor and try and get some insulation plus UFH into it as it will work much better with the ASHP. 

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28 minutes ago, Cpd said:

Mr Smarts has put together a heat loss spreadsheet but i was wondering if  @JSHarris or @PeterW or anyone on here had one that was better as a template before i venture out information that may be better presented.  As always thanks. 

 'Tis here: http://www.mayfly.eu/wp-content/uploads/2017/01/Fabric-and-ventilation-heat-loss-calculator-Master.xls

 

Lots of people here have used it.

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My aim is to try and gather the information required to identify the heating requirments for my cottage, this is my first attemp to fill in the spread sheet, i will go back over it and double check  all the numbers but i am hoping that people familiar with this set up would be able to comment on potential mistakes i have made and other more wide ranging observations. Most of the U values are taken from the calotex online calculator, they do not take into account and internal coverings such as osb, plasterboard or wood panelling. My next step will be to gather all the information on individual room sizes, only 5 including the upstairs landing / hall. Equiped with heating requiremnts and room sizes i hope to be able to then learn how the heating system may be developed.  

On 09/12/2017 at 17:10, PeterW said:

Your options on walls are varied but I would really look at that floor and try and get some insulation plus UFH into it as it will work much better with the ASHP. 

@PeterW the uninsulated concrete floor is 2390mm from the ceiling and there is no scope to raise the ceiling or to rip the slab up and go lower. 

From existing concete floor to outside entry level  the optimal build up is 130mm this gives a 2225mm floor to ceiling finished level. 

I had planned to lay

25mm calotex with battens screwed to the floor at X spacing and then lay

50mm of calotex in the opposite  direction with 50mm cross battens screwed to the 25mm.

Then chipboard screwed to the 50mm battens  

then the final floor boards in living area and ply or fermacell to then stone tile in kitchen. 

I just cant see UFH being an option but please correct me if i am wrong. 

 

As always thanks for all the help. 

 

Ok edit.... i have no idea how to get the spread sheet from my ipad to here without a screen shot, i am a dinosaur with computers..... help.

 

 

344B18A8-BCB2-4C13-AB51-C11BEA4CBEEE.jpeg

Edited by Cpd

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Is there a thread for questions about the @JSHarris heat loss spreadsheet?

 

Might be useful to collect answers in one place, so that Jeremy does not have to comment umpteen times.

 

I have decided to get to grips with my UFH, which feels as if it needs rebalancing and is definitely short-cycling though the boiler is proeprly condensing, and may be about to do a similar exercise by putting my house (and the LBB) into the ss, and I can ask lots and lots of questions. xD

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