House heating options

about2build

Hi guys and girls,
at planning stage for my new house and am looking at my heating options, house size 2550, two storey 2 ensuites main bathroom and downstairs shower room. Would like to go as renewable as possible.....what are your recommendations? Obviously need to meet ber requirements as well...please advise

BryanF

about2build wrote: »

Hi guys and girls,
at planning stage for my new house and am looking at my heating options, house size 2550, two storey 2 ensuites main bathroom and downstairs shower room. Would like to go as renewable as possible.....what are your recommendations? Obviously need to meet ber requirements as well...please advise

A couple of questions:
What is your architect recommending and has a PHPP & preliminary BER been done?
what is your expected kwh/m2 ?
are you proposing MVHR ?
(may i suggest you know the above before you go for planning permission)
when you say 'as renewable as possible' would you consider giving the money you propose to spend on small scale renewables to say a large commercial wind company where your money would be better utilised and you'd get more return for your investment:)

about2build

He has recommended using a geothermal system in combination with solar panels.....seems like a bit much to me....solar for hot water in taps geothermal for under floor heating...have just started on this now so research needs to be done further....don't know of any large wind companies that take my fancy so think i'll divert money to house plan!!

BryanF

about2build wrote: »

He has recommended using a geothermal system in combination with solar panels.....seems like a bit much to me....solar for hot water in taps geothermal for under floor heating...have just started on this now so research needs to be done further....don't know of any large wind companies that take my fancy so think i'll divert money to house plan!!

well fare enough:) May i suggest you talk about the phpp calc & the BER and your expected kwh/m2 with your arch before you go any further...you cant expect a decent answer without knowing this.. my two cents would be:
If your rural and you go for near passive levels of kwh/m2 you could use the Solar thermal with mvhr boosted by a timber gasification boiler.

another interesting option is using extra solar with a thermal store, but you'd want a really good heating eng if going that route (and the mvhr + very low kwh/m2)

Condenser

about2build wrote: »

He has recommended using a geothermal system in combination with solar panels.....seems like a bit much to me....solar for hot water in taps geothermal for under floor heating...have just started on this now so research needs to be done further....don't know of any large wind companies that take my fancy so think i'll divert money to house plan!!

Solar panels with a heat pump is overkill. The heat pump alone is more than sufficient for both ufh and dhw. Decide where you want to head with the insulation and research the various options to get you to that level. This will decide the size of HP you will need, which on a well insulated house of that size will be very small. What you spend on insulation you'll almost save in dropping down the sizes in heatpump.

headmaster

I use an oil boiler/burner and heat the house by means of "Solo Radiators". Expensive to buy, but probably the best and most economical product on the market with which to heat your house. Google them.

freddyuk

headmaster wrote: »

I use an oil boiler/burner and heat the house by means of "Solo Radiators". Expensive to buy, but probably the best and most economical product on the market with which to heat your house. Google them.

As far as I can see this is a system that uses a potentially uneconomic heat and uses electricity to make up for it's short falls thus doubling the inefficiency. Or have I got that wrong? This is what we commonly call a plinth heater? For use in kitchens where there is no space for a radiator.? Why would you put these all around the house? A good oil boiler in a properly sized and balanced radiator system with good insulation and draft proofing will knock spots off the performance of an electric fan heater.

headmaster

Freddy,
no, you are completely wrong. Like I said, google what I said, but only if you want to find out. Strange that someone would assume what the answer was, without just simply finding out. There may be more efficient ways to heat your house, if there are i'd love to know, because i've never seen them in action and i've seen quite a few in my time.

about2build

Thanks to all replys....I have more research to do. Condenser can you describe a little more on the info i need in order to establish the size of heat pump etc needed?

If you're looking for longterm lower energy costs, I would suggest building smaller and trying to maximise solar gain. Use insane amounts of insulation & an airtight structure plus Heat recovery ventillation.

All forms of fuel are likely to become more expensive in the future.

freddyuk

headmaster wrote: »

Freddy,
no, you are completely wrong. Like I said, google what I said, but only if you want to find out. Strange that someone would assume what the answer was, without just simply finding out. There may be more efficient ways to heat your house, if there are i'd love to know, because i've never seen them in action and i've seen quite a few in my time.

I did Google first and that was my conclusion. Maybe you could expand on the whether this is a hydroponic heater or not?

Sorry guys we have hijacked this thread - we should start a fresh one on this subject.

muffler

freddyuk wrote: »

Sorry guys we have hijacked this thread - we should start a fresh one on this subject.

Good idea

Condenser

about2build wrote: »

Thanks to all replys....I have more research to do. Condenser can you describe a little more on the info i need in order to establish the size of heat pump etc needed?

You'll need to decide on a u value you wish to achieve in each area, floor, windows, roof, walls. Then multiply the U value of the floor by the area of the floor, U value of the windows by areas of the windows etc. The answer when added together as a total will give you your heat loss per 1C difference between inside and outside temp. So if you wish to design for a room temp of 20C at an outside temp of -10C then you should muliply your total U value by 30 as that is the amount of degrees difference between inside and outside temp. You should really add between 5-10% to the end figure as its unlikely your insulation would be perfect.

BryanF

Condenser wrote: »

You'll need to decide on a u value you wish to achieve in each area, floor, windows, roof, walls. Then multiply the U value of the floor by the area of the floor, U value of the windows by areas of the windows etc. The answer when added together as a total will give you your heat loss per 1C difference between inside and outside temp. So if you wish to design for a room temp of 20C at an outside temp of -10C then you should muliply your total U value by 30 as that is the amount of degrees difference between inside and outside temp. You should really add between 5-10% to the end figure as its unlikely your insulation would be perfect.

great stuff condenser, but really now About2build you say your at planning stage... to put condensers answer another way..

BryanF wrote: »

talk about the phpp calc & the BER and your expected kwh/m2 with your arch before you go any further

creedp

Condenser wrote: »

Solar panels with a heat pump is overkill. The heat pump alone is more than sufficient for both ufh and dhw. Decide where you want to head with the insulation and research the various options to get you to that level. This will decide the size of HP you will need, which on a well insulated house of that size will be very small. What you spend on insulation you'll almost save in dropping down the sizes in heatpump.

Condensor, this was my view as well and then I was talking to a heat pump supplier and he told me that if you have night time electricity you are as well off heating the DHW with the immersion and bring it to 60 deg rather than with the HP. He said this is because with a 300l tank it will very rarely be cold and all you have todo is top it up nightly. I have to say Im baffled with this idea as no matter what the COP of the HP even at 45 deg is far better than the immersion. Also in your opinion what is the ideal temp for a HP to heat the DHW to and how often you should boost with immersion? If he is correct here, then it could be argued that supplementing HP with solar might not be such a over the top option?

BryanF

Condenser wrote: »

You'll need to decide on a u value you wish to achieve in each area, floor, windows, roof, walls. Then multiply the U value of the floor by the area of the floor, U value of the windows by areas of the windows etc. The answer when added together as a total will give you your heat loss per 1C difference between inside and outside temp. So if you wish to design for a room temp of 20C at an outside temp of -10C then you should muliply your total U value by 30 as that is the amount of degrees difference between inside and outside temp. You should really add between 5-10% to the end figure as its unlikely your insulation would be perfect.

Condenser, what % would you add for air-tightness or a lack of and thermal bridging

Condenser

creedp wrote: »

Condensor, this was my view as well and then I was talking to a heat pump supplier and he told me that if you have night time electricity you are as well off heating the DHW with the immersion and bring it to 60 deg rather than with the HP. He said this is because with a 300l tank it will very rarely be cold and all you have todo is top it up nightly. I have to say Im baffled with this idea as no matter what the COP of the HP even at 45 deg is far better than the immersion. Also in your opinion what is the ideal temp for a HP to heat the DHW to and how often you should boost with immersion? If he is correct here, then it could be argued that supplementing HP with solar might not be such a over the top option?

Ideally you would never heat it with an immersion as you would have the option of purchasing a domestic fresh water system on day one. Failing that, you should not push a heat pump beyond 50C as it will limit the lifetime of the equipment. How often you heat it with the immersion depends on your usage of hot water. 300L at 50C is not alot of hot water. I'd prefer a 500L cylinder.

Condenser

BryanF wrote: »

Condenser, what % would you add for air-tightness or a lack of and thermal bridging

That depends on the result of the airtightness test and the amount of thermal bridging. All heat calcs are estimates until the building is actually in service.

gear_ie

I'm at the working drawings stage of my build so pretty much in the same position as about2build. I've also been trying to find out which is the best heating option to go for. I don't want to use Oil/Gas as I see the prices going through the roof in the coming years so I want to be as economic & environmentally feasible as possible.

I aim to have an air-tight build with MVHR installed and I am currently looking at thermodynamic solar panels to heat the HW and also to heat the UFH system. Does anyone have any thoughts / comments on this? Has anyone installed/used this system to do both? (apologies is this post is in the wrong place - tis me first one!)

BryanF

gear_ie wrote: »

I'm at the working drawings stage of my build so pretty much in the same position as about2build. I've also been trying to find out which is the best heating option to go for. I don't want to use Oil/Gas as I see the prices going through the roof in the coming years so I want to be as economic & environmentally feasible as possible.

I aim to have an air-tight build with MVHR installed and I am currently looking at thermodynamic solar panels to heat the HW and also to heat the UFH system. Does anyone have any thoughts / comments on this? Has anyone installed/used this system to do both? (apologies is this post is in the wrong place - tis me first one!)

can you PM the companies details, I've yet to see any actual data from these systems. I not saying it doesn't exist, it just the last time i enquired for details of a dublin based smooth talker I never got any certs or actual data, apart from 'you wont need to use oil' but nothing about how much electricity the heat pump would use!

BryanF

thanks gear.ie we were referring to the same cowboys:)

thanks DO-more, i have checked out your UK link an asked for data, research, certs... basically anything other than 'sure tis great' hind of an answer... i revert back if i get a response..

about2build have you calculated your kwh/m2/pY yet??? dont forget your thermal bridge factor and your proposed air-tightness:)

AMG86

Go as near as you can to Passive. See http://www.seai.ie/Renewables/, http://www.proair.ie/index.php?option=com_content&task=view&id=70&Itemid=220 and http://www.passiv.de. There are many other websites that give information on building to passive house standard. The cheapest energy is the energy is that that is not used. Insulate well, build tight and ventilate is the way forward.

about2build

Getting there Bryanf arch dragging his heels a bit but have meets with two reputable heating engineers for a consult so will see what they have to say as well and get back on.....looking to go as passive as i can aswell like the other contributor said the cheapest heat is that already there !!

teepee

Hi ,
I have a log Gasification wood boiler with a 2000L Buffer tank , i have 2800sq ft house , i am very happy with the heating of the house now the house is roasting in the winter i had a good few problems with it at the early stage put i sorted them out under floor heating down stairs and rads up stair , when the rads are on at only a half a turn they are boiling no end to the heating supply with this boiler . I had a oil boiler and it was costing me around 2300 euro per year , as i get my timber for free i have no heating costs per year . But be warned that this system does not suit all !! . Theres a bit of work in the whole set up put hand on heart i find it brillant when i had the oil boiler the house was not fully warm and costing a lot of money to half heat the house .
In Summner i light the boiler once every 6 to 7 days and that does the domectic hot water no problem .
In Winter i light it every 2 to 3 days , below minus 0 deg every day .
The buffer tank is well insulated with a 1st layer of foiled insulation taped and a out foam 80mm with zip cover rap .
And theres no smoke from the boiler only for the first 10 mins of lighting it , its amazing to see the chimmney with no smoke coming out of it and the boiler at full steam as i have close neigbours smoke would be a serious issue for me !
Anyway best of luck with your choice ,
Teepee .

creedp

@ Teepee. Sounds like a very good system/setup you have going there especially as you have access to a free energy supply. To try and get a handle on the cost for someone who didn't have such a supply could you give an approx initial outlay for the system plus the amount of wood you get through annually?

Thanks

BryanF

BryanF wrote: »

thanks DO-more, i have checked out your UK link an asked for data, research, certs... basically anything other than 'sure tis great' hind of an answer... i revert back if i get a response..

Do-more,
Ive now sent these guys (the UK based thermodynamic SP) two emails with no response..
If anyone out there has data on such systems I'd be interested in see it.

teepee

Log Gasifcation cost break down ,
Boiler and buffer tank and ascociated parts 6k to 8k depending on make .
Artic load of logs {no split} 30m3 of pine 1200 Euro .
Artic load 30m3 split 1650 euro .
You would use about 12 to 15 cube a year . idealie to mix softwood with hardwood .

creedp

teepee wrote: »

Log Gasifcation cost break down ,
Boiler and buffer tank and ascociated parts 6k to 8k depending on make .
Artic load of logs {no split} 30m3 of pine 1200 Euro .
Artic load 30m3 split 1650 euro .
You would use about 12 to 15 cube a year . idealie to mix softwood with hardwood .

That's a pretty decent price for the gasification boiler and buffer tank and if the running cost are approx €800 pa (presumably wood prices would increase a little when not bought in such large bulk) then it sounds like a very good option overall. Its gas but I never head about a gasification boiler until I came onto this forum and even now I still haven't heard of it elsewhere .. how come .. is it another of the many secrets that seems to exist out there in the self-build jungle?

teepee

This u tube clip will give you a good idea of the boiler in Gasifcation mode .
http://www.youtube.com/watch?v=IQccM4VsIqA
Teepee .