Can I have both solar and a turf fuelled range heating water tank?

bfa1509

Hi,

I live in a typical countryside single floor house that is roughly 40 years old. We currently have a range that we use to burn turf. It heats a water tank located in a hot press. The range is currently the only heat source for all the hot water in the house. This is inconvenient as we need to start a fire in the summer time in order to have hot water.

We were thinking of installing vacuum solar tubes to heat the water during the summer and then move back to the range in winter, saving us turf and also unnecessary heat during the summer.

I was just wondering whether it's possible to keep the current setup but have the solar tubes installed as well?

I was in contact with Kingspan where a sales person was talking about coils and tanks but I didn't really understand what she was talking about.

Any help would very much be appreciated!

Calahonda52

Yes it is possible but in my opinion not the correct investment: its prolly 5k plus?
Whats the HW usage like: how many in the house?
I would look at an immersion cylinder or maybe even an LPG tank, lots of offers on now.
The LPG tank could be used to supplement the range

bfa1509

Calahonda52 wrote: »

Yes it is possible but in my opinion not the correct investment: its prolly 5k plus?
Whats the HW usage like: how many in the house?
I would look at an immersion cylinder or maybe even an LPG tank, lots of offers on now.
The LPG tank could be used to supplement the range

Thanks for the reply. There are 3 of us in the home at the moment but it can increase when people come home at weekends etc.

We currently have an oil immersion heater to heat the radiators. Would we be better off hooking this up to the water as well?

We won't be expecting to get a good return by going solar. Convenience is key for us.

I like the look of the LPG tank though. Does this require a boiler/burner in the home or a seperate water tank?

Calahonda52

If you have oil already then yes.
LPG would just replace the oil.
Convenience can be got with a timer on the immersion for summer, with proper zoning on the oil you could cheviot just heat cylinder only in summer at weekends if demand requires it.
Its all doable if we understand you needs and the current config exactly:)
Its late on a Sat night so too late for crunching numbers but give me an idea of what KS quoted your for supply and fit and I will do some math:)

ferryman35

There is a particular type of cylinder that can integrate all of the sources that you have mentioned easily and makes the energy from whatever sources you use available to provide central heating and hot water.

For a solid fuel stove you have to use what is called open vented plumbing - without getting too technical it basically means a system that is safe in all circumstances. This should be what you already have with your current setup

You can also connect your existing oil boiler or gas boiler if you chose to go the gas route.

In the bottom of the cylinder there is a coil - this is where the solar gets connected.

The big advantage of this system is that the solar energy you harvest can be put towards heating if you don't need it all for hotwater. Even in winter, it might only make a small contribution but every little helps.

If you'd like more details feel free to pm

Calahonda52

F35: can you give an indicative price for this rig, supplied and fitted: thanks

bfa1509

Calahonda52 wrote: »

If you have oil already then yes.
LPG would just replace the oil.
Convenience can be got with a timer on the immersion for summer, with proper zoning on the oil you could cheviot just heat cylinder only in summer at weekends if demand requires it.
Its all doable if we understand you needs and the current config exactly:)
Its late on a Sat night so too late for crunching numbers but give me an idea of what KS quoted your for supply and fit and I will do some math:)

This is very useful advice, thank you. I never got a quote from Kingspan as I couldn't decide what system to go for.

Are you saying that I can put a timer on the oil burner that lets me keep the water tank hot in summer without heating the radiators? This would be ideal if it can be done.

ferryman35 wrote: »

There is a particular type of cylinder that can integrate all of the sources that you have mentioned easily and makes the energy from whatever sources you use available to provide central heating and hot water.

For a solid fuel stove you have to use what is called open vented plumbing - without getting too technical it basically means a system that is safe in all circumstances. This should be what you already have with your current setup

You can also connect your existing oil boiler or gas boiler if you chose to go the gas route.

In the bottom of the cylinder there is a coil - this is where the solar gets connected.

The big advantage of this system is that the solar energy you harvest can be put towards heating if you don't need it all for hotwater. Even in winter, it might only make a small contribution but every little helps.

If you'd like more details feel free to pm

Thanks for the help Ferryman. Are you saying that if I go the solar route that I could connect this directly to our current water tank? Or would I need a new tank to which I could connect both the solar and the range.

Since the water tank is in a hot press, it is not insulated, so hooking up solar to this may not be ideal.

Calahonda52

Are you saying that I can put a timer on the oil burner that lets me keep the water tank hot in summer without heating the radiators? This would be ideal if it can be done.

Depends on how the zoning, if any, is set up.

Depending on the plumbing layout its not hard to do

Not having the HP insulated is like burning 50 euro, well maybe 20 euro, notes in the grate and this should be sorted as part of any project.

quentingargan

If you want to use conventional solar thermal, then you will need a triple coil cylinder with three coils - one each for solar, oil and solid fuel.

There is a cheaper option -put in photovoltaic panels. You could buy a kit of about 2kw of these for about €2500 plus VAT. This will produce the same amount of total energy as 2 large solar thermal panels, but some of the power will be used to power appliances in the house during the day. For about €300 you can then put on an device that diverts all your surplus electricity to your immersion heater.

No need to change the cylinder and no anti-freeze to change every few years. To my mind, solar PV has fallen so much in price that thermal panels are a thing of the past.

**edited** I see your current cylinder isn't insulated. You'd be mad putting solar onto this in any form. But with the above solution, you can replace it with a pretty much identical tank, except an insulated one.

Calahonda52

I agree with qq here re PV vs ST.

ferryman35

The cylinder I'm talking about is basically an open vented buffer through which you combine your energy sources. Hot water is produced via an external heat exchanger.

They're made from stainless steel (10yr warranty) , and insulated with a particularly good level of insulation so that the energy loss is minimal. There's a solar coil through which you can connect a solar thermal system &/or 2 immersion heaters.

The big advantages are that you can safely integrate a solid fuel boiler into the system, but still have mains pressure hot water at the taps. Secondly, your heat sources are supplying heat to both your hot water and heating simultaneously.

Available from 250l up to 400l and prices start at about €1500 excl VAT.

bfa1509

quentingargan wrote: »

If you want to use conventional solar thermal, then you will need a triple coil cylinder with three coils - one each for solar, oil and solid fuel.

There is a cheaper option -put in photovoltaic panels. You could buy a kit of about 2kw of these for about €2500 plus VAT. This will produce the same amount of total energy as 2 large solar thermal panels, but some of the power will be used to power appliances in the house during the day. For about €300 you can then put on an device that diverts all your surplus electricity to your immersion heater.

No need to change the cylinder and no anti-freeze to change every few years. To my mind, solar PV has fallen so much in price that thermal panels are a thing of the past.

**edited** I see your current cylinder isn't insulated. You'd be mad putting solar onto this in any form. But with the above solution, you can replace it with a pretty much identical tank, except an insulated one.

Calahonda52 wrote: »

I agree with qq here re PV vs ST.

ferryman35 wrote: »

The cylinder I'm talking about is basically an open vented buffer through which you combine your energy sources. Hot water is produced via an external heat exchanger.

They're made from stainless steel (10yr warranty) , and insulated with a particularly good level of insulation so that the energy loss is minimal. There's a solar coil through which you can connect a solar thermal system &/or 2 immersion heaters.

The big advantages are that you can safely integrate a solid fuel boiler into the system, but still have mains pressure hot water at the taps. Secondly, your heat sources are supplying heat to both your hot water and heating simultaneously.

Available from 250l up to 400l and prices start at about €1500 excl VAT.

Thanks so much for the help on this.
Is it worth my while getting all three (PV, oil, solid fuel) hooked up to the tank or would this be considered excessive?

Do I buy the cylinder and then get a plumber to hook up the oil and get a company to install the photovoltaic panels?

quentingargan

bfa1509 wrote: »

Thanks so much for the help on this.
Is it worth my while getting all three (PV, oil, solid fuel) hooked up to the tank or would this be considered excessive?

Do I buy the cylinder and then get a plumber to hook up the oil and get a company to install the photovoltaic panels?

The PV uses the standard immersion heater if you are going down that route. It can be done at any stage later if you prefer. I think changing a cylinder for a twin-coil well insulated one is always worthwhile and the plumber can use one coil for solid fuel and the other for oil. However, open vented is required in case of a power cut during a time when the solid fuel is at full throttle.

In relation to the PV, I guess it depends on your summertime use of hot water. It is very inefficient getting this from oil or solid fuel during months when you are not otherwise heating the house. During the winter, the oil and solid fuel are heating pipes in the vicinity anyhow, so it isn't that wasteful. That is why many people just use their immersion in the summer.

PV is also worthwhile if you are at home a lot during the day using electricity during that time.

bfa1509

quentingargan wrote: »

The PV uses the standard immersion heater if you are going down that route. It can be done at any stage later if you prefer. I think changing a cylinder for a twin-coil well insulated one is always worthwhile and the plumber can use one coil for solid fuel and the other for oil. However, open vented is required in case of a power cut during a time when the solid fuel is at full throttle.

In relation to the PV, I guess it depends on your summertime use of hot water. It is very inefficient getting this from oil or solid fuel during months when you are not otherwise heating the house. During the winter, the oil and solid fuel are heating pipes in the vicinity anyhow, so it isn't that wasteful. That is why many people just use their immersion in the summer.

PV is also worthwhile if you are at home a lot during the day using electricity during that time.

That's very useful info. So I only need 1 coil for both the oil and the PV panels. They heat the tank from the centre don't they?

I'll get a quote for a 500L stainless steel, insulated, twin coil, vented tank then. I'll get it installed and get a plumber to hook up the immersion then search for a suitable company to install the PV panels.

That sounds like a reasonable plan.

quentingargan

bfa1509 wrote: »

That's very useful info. So I only need 1 coil for both the oil and the PV panels. They heat the tank from the centre don't they?

I'll get a quote for a 500L stainless steel, insulated, twin coil, vented tank then. I'll get it installed and get a plumber to hook up the immersion then search for a suitable company to install the PV panels.

That sounds like a reasonable plan.

Solar thermal heats water on your roof and needs to be fed through a coil. Solar PV generates electricity which can be sent to your electric immersion instead. So it doesn't need its own coil.

Oil and solid fuel need separate coils so you need a twin coil cylinder.

Q

quentingargan

By the way, there is another post on this subject here.

ferryman35

bfa1509 wrote: »

That's very useful info. So I only need 1 coil for both the oil and the PV panels. They heat the tank from the centre don't they?

I'll get a quote for a 500L stainless steel, insulated, twin coil, vented tank then. I'll get it installed and get a plumber to hook up the immersion then search for a suitable company to install the PV panels.

That sounds like a reasonable plan.

You need to be careful...you have a mismatch in that proposal already.

500l would be very big for an open vent cylinder - I'm not saying impossible - but very unusual. All of that water has to be heated to 65'C at least once per week to prevent Legionella - and I think it would take some sunshine & solar setup to heat a 500l cylinder to that temperature reliably and routinely.

That's why you are looking for a buffer type setup with freshwater facility.

The buffer contains system water so it doesn't matter if you only get that to 55'C as long as its giving you enough hot water - and its able to deliver that water at 40-42'C. Whereas, if you are only managing to heat your potable water to 50ish 'C you are creating a massive potential health hazard for your self.

Equally you can dump your pv heat into the buffer via an immersion, the same as you would in a potable water cylinder.Though there is also an opinion that the energy you harvest from a pv setup is still too valuable to be using this way - it has a 'value' of close on 20C per kwh and you are using it to deliver you heat that might otherwise cost 5-10c / kwh.