UFH and Solar Panels

tommy.j

Hi there - I am new to this forum but have been reading some of the threads and was just after a bit of advice regarding a new build. I have just started buidling a new house in the West of Ireland ( raft being laid this week ) and am unsure what direction to go with regard to heating spec. It is a 2 storey house approx 2200 sqft blockwork house ( 150mm pumped cavity and 150mm quinnlite block on inside leaf with hollowcore floor) and am going for high quality windows so hoping house should be fairly well insulated. Also rear of house is south facing and hasbeen designed with large windows to rear to maximise solar gain. It is worth noting that house being built for mother who will eventually move to it full time but in the meantime the house will be occupied for approx 4 - 6 months of year. I had originally planned to keep simple and go for rads powered off oil boiler with solar panels on roof to heat water plus a wood burning stove to living room. However I am interested in the idea of using ufh at gf perhaps and if possible using some of the energy from the solar panels to provide a low amount of continuous heat to the house. I am not against increasing the amount of solar panels to the roof.
Just wanted to know if anyone has done this with success and could give any tips... ( apologies for the length of this thread)
Many thanks.

sinnerboy

By law you must have a DEAP assessment done for 2 reasons
1. to have published a BER certificate before the house is occupied
2. to show that you comply with building regulations Part L

A good BER assessor will also be able to use DEAP ( a software package) to answer your query on using solar to assist with ufh heating.

Do-more

Whether you go for the oil burner or not Tommy I would suggest that you install UFH anyway as it will give you the flexibility to go for just about any heat source you wish in the future.

If the house is going to be well insulated and not occupied for 6 - 8 months of the year I would suggest you look at solar air heating panels to keep the house sufficiently warm and humidity down when it is not occupied. Try Googling for more information about them.

There may even be a case for not installing a boiler initially, wait until such time as the house is going to be used year round before deciding on what to install.

In the meantime if you are staying there at say Christmas time you could use the stove for heating or even run the UFH off the Hot water tank with electric heating.

bertie1

Forget about the solar panels heating the house , this country gets longest days in the summer , & shortest in the winter , you won't get enough from the solar panels to heat the house in the winter unless you are going to put in banks & banks of them , you will get hot water on good sunny days in the winter . I have uf heating from a condensing oil boiler & solar panels heat the hot water , they are great in the summer time but have to be supplemented by the oil in the winter for the hot water , I also have a wood burning stove in the living area & its great ( winter or summer)

Do-more

bertie1 wrote: »

Forget about the solar panels heating the house

It's not a question of "heating the the house" with solar air it's about maintaining sufficient heat in the house to keep it in condition.

Solar air heaters are commonly used here in Sweden to keep poorly insulated summer cabins conditioned over the winter, these have nothing like the levels of insulation that Tommy will have in his house.

A solar air heating panel mounted vertically on a south facing wall sized correctly will produce sufficient dry warm air to keep the house in good order over the winter.

New build in sight

Sorry about hijacking your thread, but perhaps you could answer something I am unsure about... and it may be a stupid question but.... can solar panels be used for heating the UFH?? This is something i didnt think could/would happen.
Is there a particular type of panels we should use so they would contribute to heating the UFH? What would you recommend?

Many thanks

BryanF

Hi, can you tell us: your expected kwh/m2/yr heating demand: maybe from your provisional DEAP/SAP rating or from, and even better the carrying out a provisional phpp calculation on your proposed dwelling?

short answer is: if your heating demand is low enough- less than maybe 20kwh/m2/yr, solar can contribute, but really it should be considered as part of your overall strategy, that will involve some other energy source (partially ruled by your DEAP (part L Building regulation result))

solar panels with underfloor can be used in the spring and autumn to complement your main heating source (generally fantastic in summer -when we hope the sun shines). In our climate you really need some other heating source to get you through the winter (economically speaking (& from what I understand from your other input on threads, will be your expected heating demand)

New build in sight

BryanF wrote: »

Hi, can you tell us: your expected kwh/m2/yr heating demand: maybe from your provisional DEAP/SAP rating or from, and even better the carrying out a provisional phpp calculation on your proposed dwelling?

short answer is: if your heating demand is low enough- less than maybe 20kwh/m2/yr, solar can contribute, but really it should be considered as part of your overall strategy, that will involve some other energy source (partially ruled by your DEAP (part L Building regulation result))

solar panels with underfloor can be used in the spring and autumn to complement your main heating source (generally fantastic in summer -when we hope the sun shines). In our climate you really need some other heating source to get you through the winter (economically speaking (& from what I understand from your other input on threads, will be your expected heating demand)

Hi BryanF, i have abolsutely no idea what you are on about here, I have no idea what our kwh etc is. How this is defined goes completely over my head. And to add to this i have no idea what DEAP is either...

All i want to know is "if solar panels can contribute to UFH successfully and is there a solar panel that could be specifically recommended for this?"
The house will be approx 2700sqf, we do have a large open plan area with the hope of installing a double sided stove with a boiler, however this idea is starting to wane based on feedback about this type of stove and research is proving futile now too... We are still exploring ideas on how to efficiently heat the house. We will definately have oil, UFH downstairs and rads upstairs. We have unlimted supply of turf so hence the need to install a pratical stove.
Thank you.

BryanF

New build in sight wrote: »

Hi BryanF, i have abolsutely no idea what you are on about here, I have no idea what our kwh etc is. How this is defined goes completely over my head. And to add to this i have no idea what DEAP is either...

Hi this is roundabout way of answering your questions but:
http://www.seai.ie/Your_Building/BER/EPBD/
in short: carry out this assessment under Irish building regulations and this will 'roughly' help you know what is possible in your build

in NO WAY is the law but
http://www.passivehouse-international.org/index.php?page_id=188
gives a more detailed assessment process/calculation that will help answer your question

All i want to know is "if solar panels can contribute to UFH successfully and is there a solar panel that could be specifically recommended for this?"

yes it can, but as I hinted above_YOU NEED TO DO MORE CALCULATIONS. and NO there are no particular products that I would recommend (give or take a few % cop)

BryanF

@ New build in sight PM sent

bertie1

Do-more wrote: »

It's not a question of "heating the the house" with solar air it's about maintaining sufficient heat in the house to keep it in condition.

Solar air heaters are commonly used here in Sweden to keep poorly insulated summer cabins conditioned over the winter, these have nothing like the levels of insulation that Tommy will have in his house.

A solar air heating panel mounted vertically on a south facing wall sized correctly will produce sufficient dry warm air to keep the house in good order over the winter.

He asked about solar panels , not solar air.

I am talking from experience here in in Ireland with my own house , not from something that is happening in Sweden with higher levels of house insulation

Daylight hours here in winter 9.00 - 4.30 , overcast raining damp and miserable most of the time in winter. I wouldn't depend on solar panels with no alternative source of heating in those conditions.

Do-more

bertie1 wrote: »

He asked about solar panels , not solar air.

I am talking from experience here in in Ireland with my own house , not from something that is happening in Sweden with higher levels of house insulation

Daylight hours here in winter 9.00 - 4.30 , overcast raining damp and miserable most of the time in winter. I wouldn't depend on solar panels with no alternative source of heating in those conditions.

Fair play to you bertie, it's a slow day admittedly but that's given me the best laugh I've had all day!

sydthebeat

bertie1 wrote: »

He asked about solar panels , not solar air.

I am talking from experience here in in Ireland with my own house , not from something that is happening in Sweden with higher levels of house insulation

Daylight hours here in winter 9.00 - 4.30 , overcast raining damp and miserable most of the time in winter. I wouldn't depend on solar panels with no alternative source of heating in those conditions.

1. you must never have heard of a thing called "storage"
2. nobody here mentioned no alternative heating, although this is possible.
3. if you think you cant get usable heat from solar collectors on a wet winters day then you havent done your homework.


a house heated with solar collectors alone is possible, its actually happening in ireland right now. But the devil is in the detail, the house must be designed to make maximum use of free energy such as solar gains, wind shelter etc.