Air to water heat pump

citywide

Hi I am building a 3k sq foot house story & a half building it with 200mm cavity wall with full fill cavity from king span I am thinking of putting a 50mm insulated slab on the external walls sand & cement first of course. can any one tell me there experince with air to water heat pump ? or geothermal heating I would like some advice etc i would be very greatful

Thanks

fclauson

citywide wrote: »

Hi I am building a 3k sq foot house story & a half building it with 200mm cavity wall with full fill cavity from king span I am thinking of putting a 50mm insulated slab on the external walls sand & cement first of course. can any one tell me there experince with air to water heat pump ? or geothermal heating I would like some advice etc i would be very greatful

Thanks

why 200mm plus 50mm - have you done either a BER or a PHPP to see what is actually needed

What insulation are you putting into the floor and roof ?

citywide

fclauson wrote: »

why 200mm plus 50mm - have you done either a BER or a PHPP to see what is actually needed

What insulation are you putting into the floor and roof ?

Hi I didn't do the ber or phpp but I want to do it as best I can as building methods changing all the the time & I only get one chance to do it I am putting 200 mm in the floor & am thinking about a warm roof any suggestions or advice would be great thanks

fclauson

citywide wrote: »

Hi I didn't do the ber or phpp s

Ahhhh - how do you know your insulation requirements or your heat demand with out this

How will you ensure you minimise the cold bridges at windows eves doors etc without modelling or designing it

I have a 8kw hp of which just 2kw is hp and 6 is immersion
- the immersion has never come on

I knew what to buy based on modelling the build - it's the only way

citywide

fclauson wrote: »

Ahhhh - how do you know your insulation requirements or your heat demand with out this

How will you ensure you minimise the cold bridges at windows eves doors etc without modelling or designing it

I have a 8kw hp of which just 2kw is hp and 6 is immersion

- the immersion has never come on

I knew what to buy based on modelling the build - it's the only way

How big is the house ? Would you recommend the heat pump ? Do you have a buffer tank? How long have you it installed ? Is there any thing you would do different if you were doing it again I am not great with computers to be honest is there any where I can get the ber or phpp done ?

Thanks

fclauson

citywide wrote: »

How big is the house ?

350SqM

Would you recommend the heat pump ?

Yes

Do you have a buffer tank?

No - I have 35 tonnes of thermal concrete mass

How long have you it installed ?

1-year

Is there any thing you would do different if you were doing it again

No

I am not great with computers to be honest is there any where I can get the ber or phpp done ?

Thanks

You architect or engineer should know this - if they do not know what you are talking about then your should doubt if they know how to build a thermally efficient house

citywide

fclauson wrote: »

350SqMYesNo - I have 35 tonnes of thermal concrete mass 1-yearNo
You architect or engineer should know this - if they do not know what you are talking about then your should doubt if they know how to build a thermally efficient house

Both are old school but are very good @ what they do engineer/architect but it's hard to teach an old dog new tricks just won't work

BryanF

citywide wrote: »

Both are old school but are very good @ what they do engineer/architect but it's hard to teach an old dog new tricks just won't work

:eek:if they wont learn new tricks there not very good;)

as i see it an architect is kind of like a GP - if they didn't know the answer they passed you to a consultant who does but still kept control of your casefile.

so if your architect doesn't know how & where insulation should go, how much you need of it and what the best heating system option is - he consults a third party to advise - or as is often the case nowadays, you may not of paid for this service so you employ a third party to work with the architect.

having said that
your architect at th every least should have advised you at this stage that you have certain responsibilities under the H&S legislation and to carry out a BER before occupation of the dwelling (this should really be done at design stage)

if you dont know the buildings kwh/m2 heating requirement or what the overall heat loss & where its happening - how can you start talking about heat pumps?

first reduce heat loss
second reduce heat demand
lastly use appropriate renewable's

fclauson

citywide wrote: »

Both are old school but are very good @ what they do engineer/architect but it's hard to teach an old dog new tricks just won't work

Go to the kennel and get a new dog/puppy who knows the new tricks

pmac3978

Was just at ideal home exhibition and prior to today I was generally anti heat pumps. I learned a few things today.
1- getting right advice on insulation is key. Eg, on a 150 mm cavity, putting 4 inches with an air gap give a lower u value than pumping the entire cavity. Talk to the experts! They are really good. Don't just throw insulation everywhere, put it in the right place, with the right quantities.
2- was really impressed with heat pumps. Well worth putting proper preparation and planning (costs etc)
3- pay the money for the right advice, it will pay for itself many times over

fclauson

pmac3978 wrote: »

Was just at ideal home exhibition and prior to today I was generally anti heat pumps. I learned a few things today.
1- getting right advice on insulation is key. Eg, on a 150 mm cavity, putting 4 inches with an air gap give a lower u value than pumping the entire cavity.

Although mathematically correct why would you do that - I assume this was a "solid board" vendor - you will see issues elsewhere why bead is preferred over these products.

Talk to the experts! They are really good. Don't just throw insulation everywhere, put it in the right place, with the right quantities.
2- was really impressed with heat pumps. Well worth putting proper preparation and planning (costs etc)
3- pay the money for the right advice, it will pay for itself many times over

and on 3 - is the best advice you can give any body on a build

BryanF

pmac3978 wrote: »

getting right advice on insulation is key. Eg, on a 150 mm cavity, putting 4 inches with an air gap give a lower u value than pumping the entire cavity. Talk to the experts! They are really good. Don't just throw insulation everywhere, put it in the right place, with the right quantities.

will these experts insist the block layer build the inner wall the required rows higher, then installs the insulation, and will they supervise there are no gaps at ever location and provide certification to their IAB cert of this install ?

romeonovember

Hi There,

I have a query about air to water heat pumps. we have our provisional BER completed and have a rating of A2 with a rating of 49.12 KMh/M2/Per Year. we had originally planned to install solar with oil and a wood burning boiler stove, all feeding a large buffer tank (as we have plenty of good hardwood available) and this gets us compliance with Part L. However, our Architect is insisting on the heating/DHW system design being signed off by a designer as Ancilliary certifier under the new BCAR. My problem is that no suppliers (Grant, Firebird, etc) will do this. So I am bit snookered. I could go with just the oil and the solar and a standard wood burning stove, but we would loose the benefit of the wood for heating purposes.
We are now looking at other options like air to water and direct bore geothermal, so if there is any one out there who can point us in the correct direction in terms of choosing a system that would be great. I have a building services engineer on board who is doing my BER and airtightness detailing, as well as managing the cold bridging. he has modelled these using the DEAP software.

thanks and regards,

Gerry

MENACE2010

Hi
we used a company to calculate the house requirements and our plumber used -snip- for the installation of the Airsource. At the moment we have an thermia air source heatpump that works to great satisfaction .

fclauson

My advice for what its work - assuming you hose is well insulated (and I mean down to knowing what you cold bridges are) then I would recommend and HP + PV

Electric Ireland have just stopped their feed in tariff - so you will not get paid for export but a correctly sized PV will cover you based load (fridges, technology and some washing etc)

I have a 4Kwp array and produce enough electricity to operate the heating and h.w for nothing

I export around 1800Kwh annum in the nice weather

BryanF

fclauson wrote: »

My advice for what its work - assuming you hose is well insulated (and I mean down to knowing what you cold bridges are) then I would recommend and HP + PV

Electric Ireland have just stopped their feed in tariff - so you will not get paid for export but a correctly sized PV will cover you based load (fridges, technology and some washing etc)

I have a 4Kwp array and produce enough electricity to operate the heating and h.w for nothing

FC what percentage of boards members get Passive House cert ensuring those levels of attention to thermal envelop, I can only think of 3 inc you..
Are there any other boards members with PV / HP running their homes? (Genuine question not having a go)

romeonovember

Hi Fclauson,

I am just wondering what a PV panel array like yours costs? Our house will have 250mm cavity full fill with plat bonded bead (u value 0.12), triple glazed windows average u value 0.8, vaulted roof u value of 0.14, other roofs 0.11, floor slab is 0.1. Our BER assessor who is also a building services engineer has specified insulated slabs around all the window and door reveals, but we wont be using these on any other walls. we have also specified that all socket boxes be on internal walls where possible, with ones on external walls to be parged and bedded in, with all chases well sealed with scratch coat. we are also going for the marine plywood window/door frame boxes and these will be sealed in with airtight tape. all floor services will be parged and taped. we are still looking at the eaves detail as we like the idea of a SIP panel roof, but joining it to the wall-plate and the gables is the tricky bit that requires some level of detailing from our engineer, so I will have to see how it compares cost wise to a traditional cut roof, as we have a lot of it. The u value calculations are based on traditional insulation, not SIP panels.

thanks in advance,

fclauson

romeonovember wrote: »

Hi Fclauson,

I am just wondering what a PV panel array like yours costs?

check out quentingargan on this boards and ask him the question

Our house will have 250mm cavity full fill with plat bonded bead (u value 0.12), triple glazed windows average u value 0.8, vaulted roof u value of 0.14, other roofs 0.11, floor slab is 0.1. Our BER assessor who is also a building services engineer has specified insulated slabs around all the window and door reveals, but we wont be using these on any other walls.

has this been modeled - will it provide the thermal bridge numbers you are looking for

we have also specified that all socket boxes be on internal walls where possible, with ones on external walls to be parged and bedded in, with all chases well sealed with scratch coat. we are also going for the marine plywood window/door frame boxes and these will be sealed in with airtight tape.

sounds about right

all floor services will be parged and taped. we are still looking at the eaves detail as we like the idea of a SIP panel roof, but joining it to the wall-plate and the gables is the tricky bit that requires some level of detailing from our engineer,

yes the wall to eave can be a pain to get right
check the thermal model before committing to build

so I will have to see how it compares cost wise to a traditional cut roof, as we have a lot of it. The u value calculations are based on traditional insulation, not SIP panels.


thanks in advance,

Again as I say - DO THE MATHS - check the model - before you start

and then enjoy