# New build - heating options advice required.



## post-it (12 Apr 2011)

Hi all,
I am in the process of researching heating systems for a new build (2 storey; 2500 sq ft; block build) and am very confused by all the different home heating options available. 

Am just at the stage of putting together a specification (in conjunction with a draughtsman who did plans/planning permission for me) so I can put it out to tender.

Everyone I talk to has their own opinions about underfloor heating / fuel choice (gas/oil/pellet)/ radiator choice (standard / solo) / running costs etc… .. OR they are trying to sell something to me and make it out to be wonderful! All systems seem to have their pros & cons. 

I have not yet appointed an engineer for the build and was just wondering – is the engineer the person who can advise me on the best heating system for the house that will ensure it is cosy and efficient to run or are their heating specialists who can advise in this area?

To be honest I don’t know a whole lot about heating systems but I am looking for a heating system that is easy to use, responsive to changing weather and not too expensive to run – any advice appreciated.


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## villa 1 (12 Apr 2011)

Your best bet would be to contact a reputable time served plumbing contractor without vested interests in selling a particular product.
I would recommend a simple heating system with zoned control and solar hot water heating. 
I would go for radiator space heating and stay away from underfloor heating circuits. Underfloor heating is too just expensive to run and control properly. 
All gas/oil fired boilers are very efficient nowadays and stay away from pellet boilers and heat pumps. These appliances are just too expensive to buy and run and are definitely prone to breaking down.
Your main priority would be to insulate your house properly and don't overspend large capital sums on heating systems that you will never re-coup.
In my opinion engineers in charge of house builds have very little plumbing/heating knowledge.
Supplementing your space heating needs with a solid fuel stove may also be an option.
I am in the plumbing heating business in this country for over thirty years now and i've for seen endless wastefull spend on systems that are both expensive and very in-efficient.


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## bluemac (12 Apr 2011)

having been in the same situation I think its very easy to decide forget about 
how much it may cost to run after or underfloor or rads

decide what is your budget now and that will decided the system you can afford,

long term running costs are not really an issue if you dont have the extra money now, no point borrowing extra money at 4-6% to save money in the future as it most likely will not.

having said that UFH is fantastic but I think its a luxury, so again it comes back to budget

what is your budget?


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## mark1 (12 Apr 2011)

I would re-iterate what villa1's advice is having done a complete refurbishment on an old house a number of years ago, I hired a fantastic local plumbing contactor and he advised me of the most appropriate system and the pro's and cons of each of the different ones.He also worked out the Btu values ( think this is the term) each room required  and worked out the sizes of radiator needed,I suppose the most valuable item to us were thermostatic valves and cut off valves on each toilet, sink etc


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## bmcintyre (20 Apr 2011)

post-it said:


> Everyone I talk to has their own opinions about underfloor heating / fuel choice (gas/oil/pellet)/ radiator choice (standard / solo) / running costs etc… .. OR they are trying to sell something to me and make it out to be wonderful! All systems seem to have their pros & cons.


 Hi,
My 2 cents are that you have to look at the occupancy of the house as well. Underfloor isn't much use if the house is emtpy 'cause everyone's out at work for the guts of the day. It takes too long to bring the heat up and get going for it to be suitable for switching on in the evening.

But as villa said, insulate well so you reduce the amount of heat you need and that will reduce the running costs.

Oil/gas boilers are much more efficient now - they have to be a minimum of 86% efficient and the next set of Building Regs is likely to look for min. of 92% because it's possible and better all round.


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## jmrc (21 Apr 2011)

What ever about a heating system .... and good luck with that ....Be sure to catch the passive energy of the sun also. Stand on your site on of these lovely mornings and work out the best place for your biggest windows to help heat the main body of the house. Best hour I ever spent...


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## bmcintyre (21 Apr 2011)

jmrc said:


> What ever about a heating system .... and good luck with that ....Be sure to catch the passive energy of the sun also. Stand on your site on of these lovely mornings and work out the best place for your biggest windows to help heat the main body of the house. Best hour I ever spent...


Just in addition to this, there's an SEAI guide on passive solar design at seai.ie/Renewables/Renewable_Energy_for_the_Homeowner/Solar_homes_catch_the_sun.pdf


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## Construct (19 May 2011)

Go for high levels of insulation, Seal the house as best you can around joints, doors, windows etc. Both of these require a lot of attention to detail and good workmanship. You will then need a ventilation system preferably a heat recovery ventilation system. If you get all three - insulation, sealing and ventilation – right your heating requirement will be small. Start to read about passive houses.*As** jmrc* says do not forget about the passive energy that can be at very little or no cost.


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## Shane007 (21 May 2011)

UFH is an excellent choice. It is just more vital to get the installation and design of it correct at the time of installation than a traditional radiator system. Extra cost must be spent on good controls. It not, a badly designed and installed UFH system can be very expensive to correct and give you years of high fuel bills. Having said that, a good one is probably one of the best types of heating on the market. Size of house will be a major factor. For smaller houses, radiators is probably a better choice. 

Each and everyone of us will have varying opinions on each of the various systems available. Each system will have both advantages and disadvantages, so what you will have to do is handpick the various items that you want from your heating system, such as type of heat, fuel, availability, maintenance, outlay, etc.

Everyone will have an opinion, good or bad on each, so make a judgement on talking to as many people as you can who have direct experience with that system. Stay away from sales people with this regard. They are not normally technically trained and are there for one reason only, to sell you their product and not their competitors!

Spend as much as your budget will allow on insulation. Use good quality types of insulation, such as polyiso rather than fibre glass as this will lose it's U-value over time and it is best to spend on labour & materials once. Try to achieve as low an overall heat loss from the property as your budget will allow, i.e. 40w/m² or less.

Do a lot of research on heat recovery as it does have its issues also, i.e. filtration, maintenance, health, etc.

Free solar gain is a very useful tool, but your architect should be factoring this in already. If not, ask him/her why not?

Make sure you factor in the cost the lifespan of the system, before major monies have to be spent on the system again. Many people overlook this important factor, for example, if you spend €15k on a wood pellet system for a €500 saving over oil per annum, will it outlive the 15-30 years payback time before this expensive boiler needs replacing?

If you are going for wood pellet, have you got a good quality Irish Agrement Certified supplier nearby. What is the moisture content of their pellets? Have you factored in an additional cost for storage of the minimum 3 tonne delivery of pellets (buying by bag is extremely expensive) and how will you maintain the moisture content of the pellets once delivered within the storage unit/garage?

Whatever system you choose, try to install a buffer tank as an energy store. It can also be used to tie any various heat sources you choose to install.


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## quentingargan (22 May 2011)

Hee hee. It looks like you will get as much conflicting advice here as you will anywhere else.. 

My tu'pence worth is, like many others, to insulate, pay meticulour attention to detailing to minimise cold bridging, and loss of air tightness, fit heat exchange ventilation, and use radiator. 

I consider the response time of UFH to be too slow to respond, for example, to solar gain when the sun comes out. 

I also think you need to consider what fuels are available to you locally. For example, we have 140 acres of woodlands, so we are happy enough with a wood fired stove which heats our rads. If I had a stream near the house, I may have considered a heat pump. If we were buying logs off a tractor / trailer, we may find our current arrangement prohibitively expensive, depending on local availability. 

I wouldn't dismiss pellets - there are now more producers in Ireland, and there is a bit more competition. There were early cock-ups in this area with newby installers and lack of experience, but the market in this area is becoming more mature and there are more experienced installers. 

Oil prices and gas prices will probably rise. But if you don't want to make that leap of faith right now, perhaps you should make your boiler room large enough that it could accommodate a pellet stove in the future, when the time comes to replace it, and put it somewhere that a pellet silo could fit nearby. Or make it large enough to accommodate a log gassifying stove and 2,000L buffer tank so you could buy logs locally. 

You probably can consider solar water heating either way. Not a plug.. but if your house is well insulated, you should have the boiler off for 8 months of the year at least, and solar will provide you with free hot water during that time. It should be possible (just) to meet your Part L compliance for renewables with this.


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## Optimistic (23 May 2011)

hi. Take your time and do research. We have underfloor heating and love it and if we were building again we would definitely put it in again. But there is someone in our home 24/7. We did put in a secondary system to supplement the underfloor in the beginning and end of the winter and this is something you could consider and use this to boost the heat on cold spells in the autumn and spring. 
We have a wood pellet boiler and again are delighted with it. Have never had a problem with supply and quality of pellets. Again there are some very good pellet boilers and some rubbish ones. 
We had solar flat plate panels, but as you will see from previous posts we were not happy with them. We ended up taking them off and installing tubes from a local supplier. These are performing wonderfully, I am amazed with the performance, BUT do your home work on the performance of the various types/makes and don't take the word of the sales person. Look at what the print says.  The performance between various brands is eye opening. I was surprised when I saw the stats on the various systems.
If you want more info, pm me. All the best.


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## quentingargan (23 May 2011)

Optimistic said:


> We had solar flat plate panels, but as you will see from previous posts we were not happy with them. ....BUT do your home work on the performance of the various types/makes and don't take the word of the sales person. Look at what the print says.  The performance between various brands is eye opening. I was surprised when I saw the stats on the various systems.



The definitive document on the performance of solar panels is the EN12975 certificate. This outlines the "zero loss efficiency" (efficiency when the panel is at air temperature) and the "heat loss coefficients" (heat loss). There is a third and little understood item called "IAM" which deals with the effect when the sun is east or west of the panel. 

Some solar tubes have a very poor zero loss effiency, but a very high IAM because of the round shape of their collector, while other tubes are the other way around. I have seen some sales people bamboozle their customers with misleading figures from the EN12975 certs of their competitors. If you want a full explanation of IAM, you can click here. 

Some folks can do the research, but if you are non-technical, you can often get good advise from reference sites, local knowledge of a heating engineer etc.


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## Optimistic (23 May 2011)

Hi, I posted the post I wrote late last night, after a long day at work and was very tired and forgot to clarify, I do not sell pellet boilers or solar systems. 
I am sharing what I experienced and what I have learnt over the past few years. 
The most important thing I can say and this is from experience, that we now have plenty of hot water from the solar tubes we have installed. I have met other people  who have solar systems installed and they are not getting the benefit of solar like I am. My sister also has installed the same system as us and they are getting fab performance also.

All I am saying to do your home work, research the system you want. I would also say that be sure that if you are getting advice from a plumber, be sure he is unbiased opinion. Also, do your home work on the cost and ask yourself does the extra cost warrant itself in payback terms. I know with our pellet boiler we bought ours at the begining of pellet boilers and got a good deal. I don't know the price now, but if a system costs way to much to install initially pay back will be to long.

I would be also very much of the opinion to insulate and insulate and give specific detail to leakage.
All the best.


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## quentingargan (23 May 2011)

Optimistic said:


> Hi, I posted the post I wrote late last night, after a long day at work and was very tired and forgot to clarify, I do not sell pellet boilers or solar systems.
> I am sharing what I experienced and what I have learnt over the past few years....



Hi Optimisic. I hope my post wasn't taken as a criticism of yours. Far from it and I totally agree with what were saying. And by comparison, I should declare an interest in that I work in the solar (and domestic wind) industries, though I work with most of the technologies, but clearly I am an enthusiast for solar. 

In the case of a well insulated house, the benefit of tubes over flatplate is considerable, because the length of time the boiler is running is seriously reduced. If you are using the central heating for eight months of the year in a poorly insulated house, then flatplates will obviously fill the summer void, but in a well insulated house, the better insulation of vacuum systems will improve matters significantly.


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## nediaaa (23 May 2011)

Hi,
From our own experience.
 We put in a Thermia 8kw Heat pump with an air unit combined with zoned UFH. It is fantastic. Oue electricity bill for the year gone by was E1400. This is heating cooking showers. 
Also very simple to install. No pipes in the loft. Direct pressurised system so have power showers all the time.
   We have an outside stat which picks up a sudden drop in temp beffore you notice it and adjusts the temp auto.
Mst important Insulate, insulate, insulate


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## overdraftman (23 May 2011)

Underfloor heating with solar panels on the roof the best bet. It might cost more now but in the long run you'll be laughing.


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## villa 1 (23 May 2011)

overdraftman said:


> Underfloor heating with solar panels on the roof the best bet. It might cost more now but in the long run you'll be laughing.


Does that mean that you have to cover your roof with panels to heat a buffer and then in turn heat your floor slab. What about all those lovely drab dreary dull days? What will heat your house then? What about the capital cost and will you ever re-coup it?
There are interesting developments at the moment concerning domestic chp units, which if cost effective, will cut the need for ridiculous overpriced so called green energy heating systems. I have posted so many times that people are spending far too much on heating systems that they will never get their monies worth. Too many vested interests selling product with no plumbing experience


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## onq (24 May 2011)

As someone trained in building design and architecture I am not a specialist heating engineer or consulting, but I've dealt with one or two over the years.
If I was looking for a good overview from someone who had both the experience and the knowledge to talk definitively I would talk to a consulting mechanical and electrical engineer like Johnston Reid and Associates [JRA].

I have worked with JRA down the years and found his advice competent and current, although you have to ask the best questions to get the best results.
The reason I would prefer JRA over any one contractor is because they have the overview of a professional consultant and should know the pros and cons of each system.

Their website is at 

ONQ.

     [broken link removed]

     All advice on AAM is remote from the situation and cannot be relied                    upon                                                                                                  as  a          defence      or                support   -         in          and     of                   itself    -                        should                        legal                        action              be                         taken.
     Competent legal and building professionals should be asked to        advise        in                                                                                                        Real      Life      with               rights      to                inspect         and                 issue                       reports           on            the                                     matters         at                        hand.


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## onq (24 May 2011)

post-it said:


> Hi all,
> I am in the process of researching heating systems for a new build (2 storey; 2500 sq ft; block build) and am very confused by all the different home heating options available.
> 
> Am just at the stage of putting together a specification (in conjunction with a draughtsman who did plans/planning permission for me) so I can put it out to tender.
> ...



====================

Wood pellets is a subject I have discussed with many people over the years and the following is a summary of their comments:

Wood pellets systems originated in cold climate countries and are designed to work at a relatively moisture content.
In cold countries they can be stored outside with no special measures  and the air dries them out to perhaps 12% if stored outside - Ireland is  a damp country.
This means that, even if the pellets are delivered at say 14% they can  absorb enough moisture from the air to rise to say 18% - this is too  high for efficiant combustion.

This can lead to other issues and there are two follow ons from this.

Some people seem to think this is down to friction of the parts when  being transported, others suggest natural oxidation over time but a colleague of mine  has suggested a different mechanism
The heat imay be generated by the the action of microscopic bacteria  multiplying in a damp environment in association with combustible  material.

There may be a counter-intuitive method of prevention.

If pellets are stored in a manner that allows them to absorb moisture,   and if they are store in bulk and in sufficient amounts they can   spontaneously combust, like the fire burning in the centre of a coal   heap.
Thus if you want your pellets to work well, you may have to keep them  indoors and  heated to maintain their dryness, otherwise they will  absorb moisture and may combust.
If you store them in bulk in a moist temperate enviroment and bacterial  growth is the deciding factor, combusiontion seems inevitable.


The explanation above seems logical and whether it is the fact of the  matter of not, spontaneous combustion within large amounts of  combustible materials is a well known phenomenon, particularly in stored  coal heaps or spoil heaps.

Wood Pellets:

[broken link removed]

[broken link removed]

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http://www.sp.se/en/index/services/silo_fires/sidor/default.aspx

Coal and Mining:

http://en.wikipedia.org/wiki/Spoil_tip#Subterranean_combustion

http://mechgreen.wordpress.com/2011/04/24/coal-preparation-and-storage/


It would be great if readers of AAM could post sharing any experiences or similar occurrences with us.

My caveat and disclaimer at the end of my post is even more relevant when I'm offering third party advice.

I should point=t out that I have very little experience with wood pellets, Iam not connected to the "green" heating industry in any way and I am not an expert on spontaneous combustion.


ONQ.

     [broken link removed]

     All advice on AAM is remote from the situation and cannot be relied                     upon                                                                                                   as  a          defence       or                support   -         in          and     of                    itself    -                        should                         legal                        action              be                          taken.
     Competent legal and building professionals should be asked to         advise        in                                                                                                         Real      Life       with               rights      to                inspect         and                  issue                       reports           on             the                                     matters         at                         hand.


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## onq (24 May 2011)

Bit of an update here:



Also I spoke to our plumber called this morning and I raised this with him  and he confirmed he once visited a house which had the foundation of a  circa 12 ft x 12 ft shed out the back.
Apparently it had once supported timber shed that had once stored - you guessed it - wood pellets in bulk.
It spontaneously combusted once summer a few  years back.

ONQ.

      [broken link removed]

      All advice on AAM is remote from the situation and cannot be relied                      upon                                                                                                    as  a           defence       or                support   -         in          and      of                    itself    -                        should                          legal                        action              be                           taken.
      Competent legal and building professionals should be asked to          advise        in                                                                                                          Real      Life        with               rights      to                inspect         and                   issue                       reports           on              the                                     matters         at                          hand.


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## Shane007 (24 May 2011)

onq said:


> ====================
> 
> In cold countries they can be stored outside with no special measures and the air dries them out to perhaps 12% if stored outside - Ireland is a damp country.
> This means that, even if the pellets are delivered at say 14% they can absorb enough moisture from the air to rise to say 18% - this is too high for efficiant combustion.


 
+1

Wood pellets with moisture content of 12% or more is far too high and will invalidate many wood pellet boiler manufacturer's warranties. It leads to incomplete combustion. and clogging of the auger from moist dust particles.

For example, the Grant Spira Condensing wood pellet boiler stipulates that the pellets used must have the following attributes otherwise warranty is void:

1. Moisture content below 10%
2. Calorific value of 4.8 - 5.2kWh/kg
3. Ash content of <1%
4. Bulk density of 650kg/m³ or less
5. Chlorine content of 0.03% or less
6. No additives.

Generally speaking, 6mm approved premium pellets such as Balcas Brites, Bord na Mona or GWP pellets should be used. Always use Irish Agrément Certified pellets.


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## Shane007 (24 May 2011)

URGENT ALERT

The HSA is issuing an urgent alert to operators, maintenance personnel and members of the public on the dangers associated with bulk feed hoppers/tanks normally used with Wood Pellet Boilers. 
This alert follows a fatal accident where a home owner entered a bulk wood pellet storage hopper/tank and was overcome by carbon monoxide (CO) gas. CO is a colourless, odourless and tasteless gas that is highly toxic.

http://www.hsa.ie/eng/Topics/Safety_Alerts/Wood_Pellet_Feed_Hoppers_Tanks/


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