Boiler in loft

[bonebill]

I have a house to be completely refurbished. It is a bungalow with a loft space.

I have heard it mentioned that a boiler can be placed in a loft.

I have a reasonably sized loft with a reasonably large flat (gable end) wall at the back. I am planning an LPG boiler. AIUI all modern boilers are balanced flue nowadays.

So is that right? Or is there a problem putting a boiler in a loft?

I was also wondering about plumbing it.

It seems the ordinary heating/HW circuit would go:

Boiler (ground floor), 22mm pipe to
T off to vent pipe (22mm) (not sure where this would T off), short 22mm pipe to
T off to pipe to header tank (in loft) (15mm), 22mm pipe to
Pump, 22mm pipe to
3-way valve,
22mm pipe to HW tank,
22mm pipe to radiators (in parallel)
then the HW tank and radiator system returns in 22mm to the boiler

In my system though, the header tank would only be slightly above the top of the boiler. The HW tank would be on the ground floor. I thought the pump would go next to the HW tank, so on the ground floor.

Would the ordinary layout work on my system, or would I get difficulties?

Is there an alternative layout which might work better? Or should I be better off getting in an expert?

 

[doitall]

Going on your design your in trouble allready.

yes the boiler can go in the loft subject to rules and regs, and you must consider a sealed system.

Pipe work will have to be completely re-designed to the new boiler position, and you will need to get it right.

Have you consider oil at about half the price of LPG.

 

[ChrisR]

The boiler/pipe/pump sequence you describe IS the most popular convention, but I'd agree, better to seal /pressurise the system. Balanced flue could go through roof or wall, up or sideways. Don't think about doing the gas supply yourself.

 

[bonebill]

Going on your design your in trouble allready.

yes the boiler can go in the loft subject to rules and regs, and you must consider a sealed system.

Pipe work will have to be completely re-designed to the new boiler position, and you will need to get it right.

OK it looks like I'll have to consider a sealed system. It looks like I will need to get the man in.

Have you consider oil at about half the price of LPG.

The LPG people implied that oil had a higher startup cost and wasn't as convenient as LPG. Also we are quite keen on cooking on gas.

I suppose we could have an LPG cooker fed from an outdoor bottle. I was told that cookers take only a tiny proportion of the gas in a heating/cooking setup.

Could an oil-fired boiler be put in a loft? I don't know anything about oil-fired boilers. They might not be appropriate to be put in a loft and of course oil doesn't flow uphill

 

[bonebill]

Don't think about doing the gas supply yourself.

Is that to imply that LPG is even more dangerous than CNG?

IIRC LPG sinks, so an LPG leak in a loft could result in LPG building up in the house? Fun the next time you turn on a light?

 

[doitall]

All these questions.

Lpg is far more volatile than natural gas, but when installed by the book is ok, limitations are cellars or anywhere below ground level, loft is ok but as with any installation in that area extra safety is a good thing, fire proofing, fire alarms, fire valves for starters.

Personally I would consider a fire prooved room in the loft.

Standard practice is for lpg cooking and oil heating, boiler in loft would not present any major difficulties, if fitted by an oftec engineer, you can buy wall hung or floor standing boilers.

Oil generally will be more expensive to install but half the cost of lpg to run.

 

[oilman]

Oil generally will be more expensive to install but half the cost of lpg to run.

When you could be spending £400 to £600 a year on oil, that's a big amount to be adding every year for LPG. Typically changing to oil can be recouped in 2 to 3 years.

Oil boilers are HEAVY, they can go in lofts, but they need servicing and you MUST have proper access to the loft and make it a safe work space (applies whichever boiler). What about an outside boiler?

LPG installation is subsidised by the gas supplier, they don't mind as the contract has you by the balls forever. With oil you can shop around.

 

[croydoncorgi]

Lpg is far more volatile than natural gas

Exactly wrong! LPG is HEAVY with respect to air, so tends to collect in low -lying areas such as cellars - which is why it's not permitted there. Natural gas (mostly methane) is lighter than air, so disperses upwards much more quickly than LPG. Strictly speaking, NG is MUCH more 'volatile' the LPG - when did you ever hear of 'liquid methane'. It can only be liquified under refrigeration, as far as I remember.

 

[doitall]

Lpg is far more volatile than natural gas

Exactly wrong! LPG is HEAVY with respect to air, so tends to collect in low -lying areas such as cellars - which is why it's not permitted there. Natural gas (mostly methane) is lighter than air, so disperses upwards much more quickly than LPG. Strictly speaking, NG is MUCH more 'volatile' the LPG - when did you ever hear of 'liquid methane'. It can only be liquified under refrigeration, as far as I remember.

You teaching me to suck eggs again m8

Natural gas has low limits of flammability, consentrations of gas in air, as a comparison LPG has lower limits of flammability.

Typical limits of flammability (gas to air) is 5%-15% for natural gas.

Commercial propane is 2.2%-10.9%.

Commercial Butane is 1.8%-9.0%

It also has a high calorific value Butane 121.5 mj/m³ gross, Propane 95 mj/m³, natural gas 38.79 mj/m³, and requires 23 volumes of air to burn 1 volume of propane, natural gas is 1 to 10, it therefore requires more ventilation than natural gas, 1mj = 0.2778 KWh.

Add to that a typical standing pressure at the appliance of 37m/bars compaired to 20m/bars for natural gas

case prooved, although volatile was perhaps not the right word.

now I must go to bed as have to get up in 4.5 hrs

 

[PEDANTICVINDICTIVEMAN]

I didn't think lpg needed more ventilation than NG because it burned hotter, so switched off sooner ?

 

[Diyisfun]

I had my new heating system installed in the loft, as a space saving idea.

Whilst I have good access to the loft, which is boarded & has lighting.

I have my doubts now as to how good an idea this realy was.

Access to the boiler when I become less fit, could be a problem.
I have had to 'reset ' the boiler only once so far.
It does make good use of dead space.

 

[bonebill]

Oil generally will be more expensive to install but half the cost of lpg to run.

When you could be spending £400 to £600 a year on oil, that's a big amount to be adding every year for LPG. Typically changing to oil can be recouped in 2 to 3 years.

Sounds good to me.

Oil boilers are HEAVY, they can go in lofts, but they need servicing and you MUST have proper access to the loft and make it a safe work space (applies whichever boiler). What about an outside boiler?

Yes I am thinking about an outside boiler. I'm a bit light on suitable spaces outside against the wall which aren't near a window or door. I suppose I could have a metal flue pipe against the wall going up to take the exhaust away from the windows and doors. It's a single-storey building. I suppose I could have a flue going all the way up to roof height. Does that sound feasible?

Do you know where I can find a guide for siting an outside oil boiler?

LPG installation is subsidised by the gas supplier, they don't mind as the contract has you by the balls forever. With oil you can shop around.

Yes I had noticed that, although not perhaps as succinctly. Certainly with LPG they own the tank which kind of puts you in their pocket. I assume with oil you own your own tank.

 

[oilman]

Oil boilers are HEAVY, they can go in lofts, but they need servicing and you MUST have proper access to the loft and make it a safe work space (applies whichever boiler). What about an outside boiler?

Yes I am thinking about an outside boiler. I'm a bit light on suitable spaces outside against the wall which aren't near a window or door. I suppose I could have a metal flue pipe against the wall going up to take the exhaust away from the windows and doors. It's a single-storey building. I suppose I could have a flue going all the way up to roof height. Does that sound feasible?

Yes, but use a vertical balanced flue to eliminate problems from turbulanace.

Do you know where I can find a guide for siting an outside oil boiler?

the OFTEC site has the information from building regs, as does almost every boiler installation manual. It's really only the flue terminal that's the problem.

LPG installation is subsidised by the gas supplier, they don't mind as the contract has you by the balls forever. With oil you can shop around.

Yes I had noticed that, although not perhaps as succinctly. Certainly with LPG they own the tank which kind of puts you in their pocket. I assume with oil you own your own tank.

Yes the oil tank is yours.

 

[croydoncorgi]

You teaching me to suck eggs again m8 icon_wink.gif icon_wink.gif

Natural gas has low limits of flammability, consentrations of gas in air, as a comparison LPG has lower limits of flammability.

Typical limits of flammability (gas to air) is 5%-15% for natural gas.

Commercial propane is 2.2%-10.9%.

Commercial Butane is 1.8%-9.0%

It also has a high calorific value....

Eggs?...eggs? Who said anything about eggs?
You said 'volatile' when you meant 'flammable' ..so I tried to clarify the point I THOUGHT you were making.

 

[doitall]

You said 'volatile' when you meant 'flammable' ..so I tried to clarify the point I THOUGHT you were making.

Thats all right then

Don't get a fire ball rolling down the stairs either with natural gas.