# Heating Systems + Wall vents



## Marto (11 Jan 2009)

Hi,
I'm currently building and looking for some advice on the type of heating system I should install: oil, geothermal or wood log gasification

Initially I thought that I was going to stay well clear of oil but am wondering if might be the most economical option.

I got a quote of €40,000 for the installation of a geothermal system. This mentions the use of a 14kW pump. Does this pump remain on all the type or how can one approximate its ON time per year? If the pump is constantly ON  then the running costs of a such a system must be very high. What are peoples opinions of geothermal as a heating system.

I also got a quote for a wood log gasification boiler. I was wondering about the running costs of such a heating system and how much wood does it burn per year.

Also considering not putting any vents in the bedrooms. I realise their importance in rooms with an open fire but is their sole purpose in a bedroom the prevention of condensation? Could one achieve the same by ensuring that the windows are opened everyday for a couple of hours??


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## anon473 (12 Jan 2009)

all the figures that i have seen are that the geothermal heat pump uses electricity in 1:4.
i.e. that for every unit of electricity that you use you get the heat equivalent of about 4 units of electricity.
You should be aware that the water temp from a geothermal system is lower so that the radiators have to be larger to give the same heating effect.

as for vents in the bedroom - are you talking about permanently open vents. Our dbl glz windows have vents in them that can be opened for as long as you want so we dont have separate vents. they are invisible from the outside. we had a BER two days ago and i looked at our vents with the thermal imaging camera, they showed up but only just. There are other bigger energy savings out there.

anon473


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## krissovo (12 Jan 2009)

I have searched far and wide for a heating system for my home.  From doing the maths the following is what am going to install and I feel is best value for money.

1. HRV - I will have an air tight house so will implement HRV.  Total cost for a self install is €2.5k but the benefits will be a lot more. 
2. Solid fuel stove with back boiler - Room sealed stove €2.5k plus a special chimney of €3k
3, 10.4 m3 of solar panels - €4k
4, 500l water tank with heat exchangers so I can mix pressurised with non pressurised systems - €4k
5. Zoned under floor heating downstairs - €3.5k 

And lastly a simple oil burner - Included in builders finish

I have crazy quotes for geo and air pumps and everything else that is modern.


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## PaddyBloggit (12 Jan 2009)

What's HRV krissovo?


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## krissovo (12 Jan 2009)

PaddyBloggit said:


> What's HRV krissovo?



HRV = Heat Recovery Ventilation

Basically instead of wall vents this system will suck air out of the wet/warm rooms and extract them via a heat exchanger to out side through the roof in my case.  The heat exchanger will extract as much heat from the exhaust air and warm up "fresh" air coming in.  It will then distribute this air to the bedrooms & living rooms.


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## Marto (13 Jan 2009)

thanks for the replies.

Has anyone any information or experience of the wood log gasification boiler. running costs? does it suit underfloor heating? An approximation of the amount (and cost) of wood used per year.

I like the sound of this system but would love to hear what other people think of this as a heating system

My block work currently contains an open space for wall vents but would prefer not to have them. Does a window vent achieve the same effect with a lot less heat loss I'd imagine??


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## davidoco (13 Jan 2009)

krissovo said:


> 2. Solid fuel stove with back boiler - Room sealed stove €2.5k plus a special chimney of €3k
> 3, 10.4 m3 of solar panels - €4k
> 4, 500l water tank with heat exchangers so I can mix pressurised with non pressurised systems - €4k
> 5. Zoned under floor heating downstairs - €3.5k
> ...



If you intend to use the 500 litre tank as a thermal store for both the space heating and hot water I can see just general issues in trying to manage the inputs, you will have a job adjusting the oil timing and/or lighting the stove to have heat for rads or underfloor when you want it.

If the water and space are seperate then the only issue is the heat of the water from a stove for the underfloor even with blenders, and another store would be required to get value from the heat available from a stove.

To further wreck your heat have a look at the Dublin Heat Bank on http://www.heatweb.com/ link in middle of main page
then click the interactive Schematic on the top right. Run the exe.


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## Wobs (14 Jan 2009)

Marto,

A heat pump is not on all the time but can run for long periods during cold spells. They usually average  between 2500 - 3000 hours per year running time. The running cost then depends on the efficiency of the system, some can be over 500% efficient. Also stay completely away from radiators with a heat pump, they only work efficiently with UFH.

€40k sounds high for a system with  14kw heat pump. How big is your house and what else does that include (UFH, Tanks Etc.)?


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## HeadTheWall (18 Jan 2009)

krissovo said:


> I have searched far and wide for a heating system for my home.  From doing the maths the following is what am going to install and I feel is best value for money.
> 
> 1. HRV - I will have an air tight house so will implement HRV.  Total cost for a self install is €2.5k but the benefits will be a lot more.
> 2. Solid fuel stove with back boiler - Room sealed stove €2.5k plus a special chimney of €3k
> ...



What is your BER rating going to be based on all this. It sounds like overkill to me. 

If your house is going to be airtight it must be at least A3 or a fully certified passive house is A2. If this is the case you won't need underfloor heating or the oil burner for space heating purposes. 

A small heating source will be adequate. You just need to look at your needs for hot water during the winter time as the solar will cover sumer time. The stove and back boiler would suit this.


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## sydthebeat (18 Jan 2009)

HeadTheWall said:


> What is your BER rating going to be based on all this. It sounds like overkill to me.
> 
> If your house is going to be airtight it must be at least A3 or a fully certified passive house is A2. If this is the case you won't need underfloor heating or the oil burner for space heating purposes.
> 
> A small heating source will be adequate. You just need to look at your needs for hot water during the winter time as the solar will cover sumer time. The stove and back boiler would suit this.



i dont want to be picky headthewall... but..

1. the degree of airtightness doesnt depend on the rating... its is a factor, but there are many other factors which determine the rating. the current min reg standard for airtightness is 10m3/hr/m2 @ 50 pa.....
IMHO to b ereally airtight you should be aiming at a figure of less than 4.

2. fully certified houses have no relation to a BER. for example see the two passive certed houses in carlow which cactually have b1 ratings....
Th eBER is a method of comparing houses, where as the phpp (passive house methodology) is very specific to the individual dwelling.


i dont think that spec is overkill at all....

consider the installation costs versus someone putting in geothermal for a similar sized house??...


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