Heating Options
Dec 21st 2017, 3:06 pm
#16
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Joined: Dec 2004
Location: Setubal-ish
Posts: 688
Re: Heating Options
We've been in Azeitao, Setubal for 3 years now. House is about 20 years old, double glazing and ok insulation.
We primarily use the aircons, which we have in most rooms, as heating when it's not too cold. Heatpumps give a good return, you get 3-4 times the heat compared to the input electricity (which doesn't violate the laws of thermodynamics though it sounds like it does).
But the aircons struggle when the temperatures are lower, the cool parts outside will ice up, so they have to go into a defrost mode to keep the coils clear. And the efficiency drops off.
Luckily, the house has mains gas and had central heating with radiators already when we moved in, the boiler also does on demand hot water. We'd tended not to use this for heating because it didn't seem to work very well, but recently replaced the boiler and it works great now. Really nice to have for the couple of months here when it can get down towards freezing.
Not sure I'd want to use bottled gas for heating? I would imagine that's ok for cooking, but how often do you need to change bottles if you're running it on long stints for heating, especially if doing your hot water too.
I've heard wood pellet burners are cheapest option to run, but expensive to install, especially if you have the feed mechanism, someone told me around 6k EUR.
If I was building or renovating, I'd be tempted to go for really top notch insulation, enough that I could just use aircon units to heat, and maybe a wood burner for living room when it gets very cold.
We primarily use the aircons, which we have in most rooms, as heating when it's not too cold. Heatpumps give a good return, you get 3-4 times the heat compared to the input electricity (which doesn't violate the laws of thermodynamics though it sounds like it does).
But the aircons struggle when the temperatures are lower, the cool parts outside will ice up, so they have to go into a defrost mode to keep the coils clear. And the efficiency drops off.
Luckily, the house has mains gas and had central heating with radiators already when we moved in, the boiler also does on demand hot water. We'd tended not to use this for heating because it didn't seem to work very well, but recently replaced the boiler and it works great now. Really nice to have for the couple of months here when it can get down towards freezing.
Not sure I'd want to use bottled gas for heating? I would imagine that's ok for cooking, but how often do you need to change bottles if you're running it on long stints for heating, especially if doing your hot water too.
I've heard wood pellet burners are cheapest option to run, but expensive to install, especially if you have the feed mechanism, someone told me around 6k EUR.
If I was building or renovating, I'd be tempted to go for really top notch insulation, enough that I could just use aircon units to heat, and maybe a wood burner for living room when it gets very cold.
Dec 22nd 2017, 9:42 am
#17
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Re: Heating Options
Thanks
Sounds like air con and wood burner is becoming a (general) consensus, although not the only option
Sounds like air con and wood burner is becoming a (general) consensus, although not the only option
Dec 22nd 2017, 5:14 pm
#18
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Joined: Jun 2012
Posts: 3,032
Re: Heating Options
It depends on your preferences and budget; retrofitting underfloor heat is not a small job!
We wanted to demolish most of the interior walls, so we were already in pretty deep.
The entire floor was jackhammered into rubble and removed; then another 20cm was dug out before pouring new concrete, then insulation, then more concrete with the floor loops cast in. concrete pillars support a monster steel beam that replaces the bearing walls we took out.
new doors, windows, electrics, plumbing, kitchen, data wires... basically, we supported the habitation license on posts and built a new house under it.
the underfloor heat has 3 advantages;
once installed, it doesn't take up any of your living space.
It works at a more moderate temperature than other systems, which is great for efficiency if you use non-fuel heat [solar or heat pump].
The heat is very evenly distributed.
On a new build, I think it's nuts to not install floor loops, since the cost would be very small during construction. But on a renovation, it's a pretty expensive option.
We wanted to demolish most of the interior walls, so we were already in pretty deep.
The entire floor was jackhammered into rubble and removed; then another 20cm was dug out before pouring new concrete, then insulation, then more concrete with the floor loops cast in. concrete pillars support a monster steel beam that replaces the bearing walls we took out.
new doors, windows, electrics, plumbing, kitchen, data wires... basically, we supported the habitation license on posts and built a new house under it.
the underfloor heat has 3 advantages;
once installed, it doesn't take up any of your living space.
It works at a more moderate temperature than other systems, which is great for efficiency if you use non-fuel heat [solar or heat pump].
The heat is very evenly distributed.
On a new build, I think it's nuts to not install floor loops, since the cost would be very small during construction. But on a renovation, it's a pretty expensive option.
Dec 24th 2017, 4:00 pm
#19
Forum Regular
Joined: Aug 2007
Posts: 224
Re: Heating Options
As captainflack clearly explains you can consider a heat pump of some sort. I think it is the ideal for a location as Caparica which displays mild temperatures, but can nevertheless get very cold uncomfortable, being a wet cold and the concrete houses sucking the produced heat. If you can put some underfloor heating system which is not solely running on gas or electricity that is your best option, meaning you could have some form of water/soil, or water/air heat pump. Daikin´s Altherma is a option, but others are available. This is a sort of an air con but using underfloor units. Sometimes you have to have some outdoor space to bury the heat exchangers. It is never a bad idea to have wood burners (salamandras are by far the most efficient ). Ah, in my oipinion for concrte houses I would select inside isolation
Dec 30th 2017, 1:27 am
#20
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Re: Heating Options
Thanks all
Underfloor would be good, but the investment is not in our plans. Also, upstairs only has thin wooden floors.
The '3 - 4 times more efficient than electric heating' has been bugging me (since I know that resistance electric is 100% efficient - If we ignore the efficiency of the power station), until I found this,
'If you live in an area that does not have temperature extremes, then a heat pump can save you 30 percent to 40% off heating and cooling costs associated with a comparable electric system. Since heat pumps are designed to move heat instead of create it, they are usually four times more efficient than electric heaters. For less moderate climates where temperatures can drop more dramatically, electrical systems are more reliable, and can provide more heat over a given area than a heat pump. However, heat pumps dehumidify the air much better than electric systems. This can be a benefit in humid climates but a negative in dryer climates.'
Humidity has always been a PITA for me in Portugal in winter (apparent temps and spore allergies) , another plus for air con (when I say this I mean heat pumps)
Above all I think good insulation is the no. 1 priority
Underfloor would be good, but the investment is not in our plans. Also, upstairs only has thin wooden floors.
The '3 - 4 times more efficient than electric heating' has been bugging me (since I know that resistance electric is 100% efficient - If we ignore the efficiency of the power station), until I found this,
'If you live in an area that does not have temperature extremes, then a heat pump can save you 30 percent to 40% off heating and cooling costs associated with a comparable electric system. Since heat pumps are designed to move heat instead of create it, they are usually four times more efficient than electric heaters. For less moderate climates where temperatures can drop more dramatically, electrical systems are more reliable, and can provide more heat over a given area than a heat pump. However, heat pumps dehumidify the air much better than electric systems. This can be a benefit in humid climates but a negative in dryer climates.'
Humidity has always been a PITA for me in Portugal in winter (apparent temps and spore allergies) , another plus for air con (when I say this I mean heat pumps)
Above all I think good insulation is the no. 1 priority
Dec 30th 2017, 7:33 am
#21
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Joined: Jun 2012
Posts: 3,032
Re: Heating Options
All air conditioners are heat pumps; although the term is used to describe the reverse cycle ones that also provide heat.
The optimistic figures are always used, 3-400%. Maybe, every now and then, under ideal conditions, those numbers are achieved. As you interior gets warmer and the exterior gets colder, efficiency drops.
There are some alternate systems for extracting heat; ground loops [incorrectly and falsely advertised as 'geothermal heating'], solar collectors [work great on sunny days when you don't need much heat], but whether these systems merit their high installation cost is doubtful.
One thing is sure; sales people work on commission. My experience is that they don't use numbers for engineering, they use numbers for profit.
For reducing humidity while cooling, air-conditioning does a great job. The unit condenses the water from the air and you can see it drain out.
For dehumidifying while heating, pretty much all you need to do is heat 5 degrees or more. The heated air is able to hold more water and although the actual water in it is not decreased, the lowered relative humidity is all you need. Any heating system is equal for dehumidifying.
A common problem here in Portugal is uninsulated outer walls, because they will stay cold [put your hand on one!].
Like a cold drink on a warm day, condensation will form on it. Also inside cupboards and closets attached to it. Mold will form, especially in closed spaces and bathrooms [where the humidity is always higher].
The best way to deal with the problem is to insulate; the popular solution in this mild climate is to plate the exterior of the house with ridged foam sheets, and plaster over it with cement to give the house the traditional Mediterranean look again.
The masonry becomes a heat buffer, which can be advantageous from an energy conservation point of view, absorbing heat in day and releasing it at night.
A full insulation and vapor seal [as is normal in northern Europe] would be better, but it's just not done in Portugal. As a refit, it could be done by insulating on the inside of your house, with interior plasterboard. That would give a nice finish, but you lose interior space, all the wiring needs to be moved or replaced [that can be a good thing of course], and so on.
With the exterior insulation there will be heat loss at the foundation, around the windows and doors, and at the eves of the roof.
Roof or ceiling insulation has to be done too or it's no use. Under floor insulation would be a good thing, but is a huge and disruptive job and not as vital. However, a cold floor isn't very nice.
Despite all the compromises from an energy engineering perspective, everyone I've talked to who has had the exterior insulation done is really happy with the results, and I think that's the proof that the job is viable.
I always intended to have it done, but so far have not. My floor and ceiling is insulated and we have a heat recovery ventilation system installed; that makes a HUGE difference, and I recommend getting one.
I've built a few homes, insulated, sheeted, and installed heating systems, designed and assembled air-conditioning systems, wiring, plumbing, and drainage. I'm into this stuff.
My advice for the non- engineer home owner is to get a heating / cooling / engineering architect person to crunch the numbers and advise you, who is not going to profit from the sale of the machinery or the work, and whose advice might possibly be unbiased.
The optimistic figures are always used, 3-400%. Maybe, every now and then, under ideal conditions, those numbers are achieved. As you interior gets warmer and the exterior gets colder, efficiency drops.
There are some alternate systems for extracting heat; ground loops [incorrectly and falsely advertised as 'geothermal heating'], solar collectors [work great on sunny days when you don't need much heat], but whether these systems merit their high installation cost is doubtful.
One thing is sure; sales people work on commission. My experience is that they don't use numbers for engineering, they use numbers for profit.
For reducing humidity while cooling, air-conditioning does a great job. The unit condenses the water from the air and you can see it drain out.
For dehumidifying while heating, pretty much all you need to do is heat 5 degrees or more. The heated air is able to hold more water and although the actual water in it is not decreased, the lowered relative humidity is all you need. Any heating system is equal for dehumidifying.
A common problem here in Portugal is uninsulated outer walls, because they will stay cold [put your hand on one!].
Like a cold drink on a warm day, condensation will form on it. Also inside cupboards and closets attached to it. Mold will form, especially in closed spaces and bathrooms [where the humidity is always higher].
The best way to deal with the problem is to insulate; the popular solution in this mild climate is to plate the exterior of the house with ridged foam sheets, and plaster over it with cement to give the house the traditional Mediterranean look again.
The masonry becomes a heat buffer, which can be advantageous from an energy conservation point of view, absorbing heat in day and releasing it at night.
A full insulation and vapor seal [as is normal in northern Europe] would be better, but it's just not done in Portugal. As a refit, it could be done by insulating on the inside of your house, with interior plasterboard. That would give a nice finish, but you lose interior space, all the wiring needs to be moved or replaced [that can be a good thing of course], and so on.
With the exterior insulation there will be heat loss at the foundation, around the windows and doors, and at the eves of the roof.
Roof or ceiling insulation has to be done too or it's no use. Under floor insulation would be a good thing, but is a huge and disruptive job and not as vital. However, a cold floor isn't very nice.
Despite all the compromises from an energy engineering perspective, everyone I've talked to who has had the exterior insulation done is really happy with the results, and I think that's the proof that the job is viable.
I always intended to have it done, but so far have not. My floor and ceiling is insulated and we have a heat recovery ventilation system installed; that makes a HUGE difference, and I recommend getting one.
I've built a few homes, insulated, sheeted, and installed heating systems, designed and assembled air-conditioning systems, wiring, plumbing, and drainage. I'm into this stuff.
My advice for the non- engineer home owner is to get a heating / cooling / engineering architect person to crunch the numbers and advise you, who is not going to profit from the sale of the machinery or the work, and whose advice might possibly be unbiased.
Dec 30th 2017, 10:19 am
#22
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Joined: Jan 2008
Location: Península de Setúbal
Posts: 407
Re: Heating Options
All air conditioners are heat pumps; although the term is used to describe the reverse cycle ones that also provide heat.
The optimistic figures are always used, 3-400%. Maybe, every now and then, under ideal conditions, those numbers are achieved. As you interior gets warmer and the exterior gets colder, efficiency drops.
There are some alternate systems for extracting heat; ground loops [incorrectly and falsely advertised as 'geothermal heating'], solar collectors [work great on sunny days when you don't need much heat], but whether these systems merit their high installation cost is doubtful.
One thing is sure; sales people work on commission. My experience is that they don't use numbers for engineering, they use numbers for profit.
For reducing humidity while cooling, air-conditioning does a great job. The unit condenses the water from the air and you can see it drain out.
For dehumidifying while heating, pretty much all you need to do is heat 5 degrees or more. The heated air is able to hold more water and although the actual water in it is not decreased, the lowered relative humidity is all you need. Any heating system is equal for dehumidifying.
A common problem here in Portugal is uninsulated outer walls, because they will stay cold [put your hand on one!].
Like a cold drink on a warm day, condensation will form on it. Also inside cupboards and closets attached to it. Mold will form, especially in closed spaces and bathrooms [where the humidity is always higher].
The best way to deal with the problem is to insulate; the popular solution in this mild climate is to plate the exterior of the house with ridged foam sheets, and plaster over it with cement to give the house the traditional Mediterranean look again.
The masonry becomes a heat buffer, which can be advantageous from an energy conservation point of view, absorbing heat in day and releasing it at night.
A full insulation and vapor seal [as is normal in northern Europe] would be better, but it's just not done in Portugal. As a refit, it could be done by insulating on the inside of your house, with interior plasterboard. That would give a nice finish, but you lose interior space, all the wiring needs to be moved or replaced [that can be a good thing of course], and so on.
With the exterior insulation there will be heat loss at the foundation, around the windows and doors, and at the eves of the roof.
Roof or ceiling insulation has to be done too or it's no use. Under floor insulation would be a good thing, but is a huge and disruptive job and not as vital. However, a cold floor isn't very nice.
Despite all the compromises from an energy engineering perspective, everyone I've talked to who has had the exterior insulation done is really happy with the results, and I think that's the proof that the job is viable.
I always intended to have it done, but so far have not. My floor and ceiling is insulated and we have a heat recovery ventilation system installed; that makes a HUGE difference, and I recommend getting one.
I've built a few homes, insulated, sheeted, and installed heating systems, designed and assembled air-conditioning systems, wiring, plumbing, and drainage. I'm into this stuff.
My advice for the non- engineer home owner is to get a heating / cooling / engineering architect person to crunch the numbers and advise you, who is not going to profit from the sale of the machinery or the work, and whose advice might possibly be unbiased.
The optimistic figures are always used, 3-400%. Maybe, every now and then, under ideal conditions, those numbers are achieved. As you interior gets warmer and the exterior gets colder, efficiency drops.
There are some alternate systems for extracting heat; ground loops [incorrectly and falsely advertised as 'geothermal heating'], solar collectors [work great on sunny days when you don't need much heat], but whether these systems merit their high installation cost is doubtful.
One thing is sure; sales people work on commission. My experience is that they don't use numbers for engineering, they use numbers for profit.
For reducing humidity while cooling, air-conditioning does a great job. The unit condenses the water from the air and you can see it drain out.
For dehumidifying while heating, pretty much all you need to do is heat 5 degrees or more. The heated air is able to hold more water and although the actual water in it is not decreased, the lowered relative humidity is all you need. Any heating system is equal for dehumidifying.
A common problem here in Portugal is uninsulated outer walls, because they will stay cold [put your hand on one!].
Like a cold drink on a warm day, condensation will form on it. Also inside cupboards and closets attached to it. Mold will form, especially in closed spaces and bathrooms [where the humidity is always higher].
The best way to deal with the problem is to insulate; the popular solution in this mild climate is to plate the exterior of the house with ridged foam sheets, and plaster over it with cement to give the house the traditional Mediterranean look again.
The masonry becomes a heat buffer, which can be advantageous from an energy conservation point of view, absorbing heat in day and releasing it at night.
A full insulation and vapor seal [as is normal in northern Europe] would be better, but it's just not done in Portugal. As a refit, it could be done by insulating on the inside of your house, with interior plasterboard. That would give a nice finish, but you lose interior space, all the wiring needs to be moved or replaced [that can be a good thing of course], and so on.
With the exterior insulation there will be heat loss at the foundation, around the windows and doors, and at the eves of the roof.
Roof or ceiling insulation has to be done too or it's no use. Under floor insulation would be a good thing, but is a huge and disruptive job and not as vital. However, a cold floor isn't very nice.
Despite all the compromises from an energy engineering perspective, everyone I've talked to who has had the exterior insulation done is really happy with the results, and I think that's the proof that the job is viable.
I always intended to have it done, but so far have not. My floor and ceiling is insulated and we have a heat recovery ventilation system installed; that makes a HUGE difference, and I recommend getting one.
I've built a few homes, insulated, sheeted, and installed heating systems, designed and assembled air-conditioning systems, wiring, plumbing, and drainage. I'm into this stuff.
My advice for the non- engineer home owner is to get a heating / cooling / engineering architect person to crunch the numbers and advise you, who is not going to profit from the sale of the machinery or the work, and whose advice might possibly be unbiased.
Thank you!
That is very helpful indeed in unravelling what the terms being used in the industry actually mean in real engineering terms.
Cheers!
Dec 31st 2017, 5:10 am
#23
Lost in BE Cyberspace
Joined: Nov 2013
Posts: 6,313
Re: Heating Options
Not going to help you much! but we have underfloor air duct heating form an oil fired boiler (came with the house) We installed a log burning stove in the living room. The house was built by previous British owner and to a high standard. It is unusual for it to fall below 18/20 deg without any form of heating winter or summer. Neither OH or I like it warmer than that usually. Only if icy winds are blowing (which is rare in the Algarve) Our heating system is so efficient that we can get away with having it on for quite short periods so it doesn't cost us overmuch at all
The only thing I would say about the pellet system is that its a bit of a pain for any close neighbours. It frankly stinks.. Our neighbour has one with a very tall chimney n the front garden.. It blows all over our garden,the smell is awful...
The only thing I would say about the pellet system is that its a bit of a pain for any close neighbours. It frankly stinks.. Our neighbour has one with a very tall chimney n the front garden.. It blows all over our garden,the smell is awful...
Dec 31st 2017, 12:33 pm
#24
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Joined: Jan 2008
Location: Península de Setúbal
Posts: 407
Re: Heating Options
So, thinking aloud, 'as I see it' ....
(Whenever I say 'air-con' I mean reversible air heat pumps)
1. Interior vs exterior insulation - What are the pros and cons one v the other?
Thanks, and a Happy New Year!
Leigh
(Whenever I say 'air-con' I mean reversible air heat pumps)
1. Interior vs exterior insulation - What are the pros and cons one v the other?
- Exterior uses thermal mass of walls as a 'reservoir'/'damper')'? When we have periods of really hot days and nights in summer for any length of time I have found this to be a disadvantage as there is no cooling cycle, although I am not sue of this.
- Exterior heat losses to foundations etc greater?
- Exterior presumably has to have interior roof insulation
- Interior - what about condensation between the insulation and the (cold in winter) concrete walls?
- Interior cheaper/easier?
- Interior loss of space (not a prob for us and we need to redo electrics)?
- Interior we would like to keep the existing 'knobbly' surface on the walls, how to do this on plasterboard?
- etc.
- 2 mechanisms:
- Any heating means that rel humid goes down without any water extraction?
- Air-con extracts water due to condensation (hence drain pipes)?
- etc.
- 'Air-con' Cheaper/simpler to buy & install?
- 'Air-con' large market in PT , hence good choice, availability, prices and maintenance?
- 'Air-con' can cool in summer when required
- 'Air-con' becomes inefficient for large temp differentials (and can not function at very low temps)?
- 'Air-con' low thermal mass (Cp) so quick warm and cooling times (can be advantage or disadvantage)?
- Water radiators high thermal mass (Cp) so slow warm and cool times (can be advantage or disadvantage)?
- Underfloor very efficient, low space, even distribution but expensive/disruptive to install? Also what about any future maintenance when problems occur?
- Underground heat exchangers in system great but expensive?
- Closed ventilation systems with In/out heat exchangers (also underground heat exchanger possible) very efficient and good for allergies? But what about humidity build up?
- Salamandras efficient (and agreeable)?
- Salamandras best to have the chimney as a vertical heat exchanger 'in the open' in the room (and through room above)?
- Salamandras in living areas with 'Air con' in upstairs bedrooms etc could be a good 'hybrid'
- Gas boiler for heating would require a storage pressure vessel rather than bottles (we have no mains gas)?
- etc
Thanks, and a Happy New Year!
Leigh
Jan 1st 2018, 10:18 am
#25
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Joined: Jun 2009
Posts: 657
Re: Heating Options
I can see you have put a lot of thought into the project. Just a little input from my personal experience that may (or may not) prompt a few more thoughts.
If external insulation is bonded to the wall correctly there is no space for condensation to form - (Capoto system widely used in Portugal - external polystyrene with mechanically strong render finish). Best system really so walls retain heat in winter and are slow to transfer heat in Summer.
Wet underfloor system is always the best but consider doing a smaller zone - main living areas + master bedroom. The is about the limit of a 4kw Salamander with back boiler in terms of performance. If you don't want to dig up the floors then just chase in some 'micro-bore' pipes when you are doing the walls and add a few radiators - some nice styles around now.
AC is great in Summer (consider installing some PV panels to run it for cooling for free). It's also ugly to see and a external units can be noisy - consider combining two internal units to one external unit to save 'wall clutter'.
AC is less great in Winter but fine for rooms that are not used much or to get a quick top up. They don't heat the building structure well they just make warm air.
Salamander best fitted on an internal wall to get max output from flue temperature. There are some interesting flue coil options for extra heat extraction that pull out enough heat to run another radiator. Salamander with back boiler is nice and efficient and will do domestic hot water as well.
Your thoughts about 'Hybrid' deserve encouragement, great to have several heating options for different seasons and for different areas of the house - probably no need to heat an empty guest bedroom.
Take a look at pellet burners + micro-bore central heating with rads. A lot of decisions depend on your house layout and the way you use the space.
Ultimate heating for a new build or (rebuild if you have access to floors to fit a UFH matrix) is - solar water heating panels on roof + large indirect tank with multiple coils, connection to a back boiler, + a heat pump for cloudy days. Anyone building a house these days should at least put the pipes in ready for future use. (Plastic tube laid on to a polystyrene bed) Not a big cost if done during construction. Add the rest of the system when its affordable.
Also note that it's possible to use wet underfloor heating for underfloor cooling if you have a heat pump. Its discreet and efficient and if the heat pump is PV powered then its also free to run.
Hope this helps just a little - are we related by the way
If external insulation is bonded to the wall correctly there is no space for condensation to form - (Capoto system widely used in Portugal - external polystyrene with mechanically strong render finish). Best system really so walls retain heat in winter and are slow to transfer heat in Summer.
Wet underfloor system is always the best but consider doing a smaller zone - main living areas + master bedroom. The is about the limit of a 4kw Salamander with back boiler in terms of performance. If you don't want to dig up the floors then just chase in some 'micro-bore' pipes when you are doing the walls and add a few radiators - some nice styles around now.
AC is great in Summer (consider installing some PV panels to run it for cooling for free). It's also ugly to see and a external units can be noisy - consider combining two internal units to one external unit to save 'wall clutter'.
AC is less great in Winter but fine for rooms that are not used much or to get a quick top up. They don't heat the building structure well they just make warm air.
Salamander best fitted on an internal wall to get max output from flue temperature. There are some interesting flue coil options for extra heat extraction that pull out enough heat to run another radiator. Salamander with back boiler is nice and efficient and will do domestic hot water as well.
Your thoughts about 'Hybrid' deserve encouragement, great to have several heating options for different seasons and for different areas of the house - probably no need to heat an empty guest bedroom.
Take a look at pellet burners + micro-bore central heating with rads. A lot of decisions depend on your house layout and the way you use the space.
Ultimate heating for a new build or (rebuild if you have access to floors to fit a UFH matrix) is - solar water heating panels on roof + large indirect tank with multiple coils, connection to a back boiler, + a heat pump for cloudy days. Anyone building a house these days should at least put the pipes in ready for future use. (Plastic tube laid on to a polystyrene bed) Not a big cost if done during construction. Add the rest of the system when its affordable.
Also note that it's possible to use wet underfloor heating for underfloor cooling if you have a heat pump. Its discreet and efficient and if the heat pump is PV powered then its also free to run.
Hope this helps just a little - are we related by the way
Jan 1st 2018, 11:27 pm
#26
Forum Regular
Joined: Jun 2014
Posts: 125
Re: Heating Options
Our house is old and cold and no heating .. I was interested to read about the exterior insulation, as we have not yet done anything with the outer walls I am thinking this could the way to go.
Is it easy to purchase items and do yourself or is it a specialist job.
Also do you have any idea of cost
Thanks for all the info everyone has added its been really helpful 😎😎
Is it easy to purchase items and do yourself or is it a specialist job.
Also do you have any idea of cost
Thanks for all the info everyone has added its been really helpful 😎😎
Jan 2nd 2018, 5:54 am
#27
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Joined: Mar 2014
Location: East Algarve
Posts: 1,000
Re: Heating Options
I considered external wall insulation in the past but was put off by one problem: my tiled roof would have to be altered so that it overlapped the increased wall thickness all round. As we have a single storey "old folks' bungalow" built in 1996, the roof has a large perimeter and the work and expense would be considerable. Has anyone got experience of this?
The walls are ventilated cavity so do not suffer from damp problems. However, as a retired civil engineer, I can't bear to think of the heat loss in winter months. I doubled the roof insulation because that was relatively cheap and easy: we have roof lofts all round so it was an easy DIY job. I searched around for someone who could fill the wall cavity with insulation but there were no companies doing this in 2003/4. Has this changed in the Algarve yet? I've been asleep for quite a while!
I have to say though that after installing night storage heaters many years ago, we have a cosy house in the winter, especially in our bathroom. The original water based gas-fired central heating was ridiculously expensive to run on bottled gas; no mains gas here. I would like to reduce the electricity bill. Perhaps I should generate some free electricity using PV panels. Advice and suggestions would be very welcome.
Happy New Year everyone.
The walls are ventilated cavity so do not suffer from damp problems. However, as a retired civil engineer, I can't bear to think of the heat loss in winter months. I doubled the roof insulation because that was relatively cheap and easy: we have roof lofts all round so it was an easy DIY job. I searched around for someone who could fill the wall cavity with insulation but there were no companies doing this in 2003/4. Has this changed in the Algarve yet? I've been asleep for quite a while!
I have to say though that after installing night storage heaters many years ago, we have a cosy house in the winter, especially in our bathroom. The original water based gas-fired central heating was ridiculously expensive to run on bottled gas; no mains gas here. I would like to reduce the electricity bill. Perhaps I should generate some free electricity using PV panels. Advice and suggestions would be very welcome.
Happy New Year everyone.
Last edited by BillBullock; Jan 2nd 2018 at 6:02 am.
Jan 2nd 2018, 8:44 am
#28
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Posts: 657
Re: Heating Options
External cladding is likely to cost around 30 Euros per square metre so do your rough calculations at that rate before shopping around. It varies according to the thickness required and the layout of the property - (curved walls cost extra). 40mm is a good minimum thickness but more is better. It's possible to put a permanently coloured render overall that makes a long lasting finish that makes it unnecessary to paint for years - so there are some further benefits 
Jan 2nd 2018, 1:12 pm
#29
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Joined: Jan 2008
Location: Península de Setúbal
Posts: 407
Re: Heating Options
Thanks!
More thoughts / points for my list:
Thanks again
Leigh
More thoughts / points for my list:
- Thanks for Exterior cladding rough estimate, I think it will probably be a big outlay on our house & extending tiled eaves might be even more so. Looks good though, and is preferred option of upper management, and if this is well done then heating can be much lower spec.
- Celotex type insulation / plasterboard could be less easy as inside walls full of nooks and crannies and openings etc - there's relatively little flat surface. But I am guessing that normally it is the cheaper / easier option?
- We have only a small loft space in the apex of the roof. Lots of sloping roof which is just reinf. concrete, which means Celotex there I guess?
- Air con plan was one external unit supplying various internal units, as my Brother in law has in his house in Lisbon.
- Very large all round garden, external units can be positioned to avoid noise / unsightliness
- Not sure about just air con for the two bedrooms that are to be used every night. It only heats air, hence quick cooling (but also quick heating) and also not efficient in cold outside temps, but the bedrooms in our old house on the UK North Sea coast right on the chilly beach were fine with a 1970's ducted hot air system (although that was mains gas fired). Also, in summer cooling good to have in the bedrooms of that house apparently (although that is from experience with current lack of any insulation).
- Salamandra on interior wall for sure, but my friend has his standing away from any walls with the flue visible straight up to the high open, (i.e. no loft space) ceiling which I like. Any disadvantages to this?
- Back boilers for salamandras sounds very interesting. Maybe a radiator from the planned living room (25 m²) and 'back room' (35 m², a second living room come guest room) salamandras which are directly below each bedroom, at 18 & 25 m² respectively? But this needs pumps too I presume?
- Will look into salamandra flu coils (so that's what they are called!) Couldn't they just be in the bedrooms upstairs instead of having a back boiler and then pumping up hot water to a rad?
- Underfloor 'wet' heating: I am still shying away from this due to cost and work, although if it is only for the living room it may be feasible with a salamandra back boiler? Also Mrs S. wants to keep the tiled floors and rugs she has had there since childhood, but then the rugs would have to go...
Thanks again
Leigh
Jan 2nd 2018, 5:37 pm
#30
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Joined: Jun 2009
Posts: 657
Re: Heating Options
1x Central AC Unit with multiple internal units is great but you have no fallback in case of equipment failure/loss of gas etc.
Back boiler connected direct to UFH is no good as the temperature of the water is too high. You have to heat a large tank of water using an indirect coil to get the temperature right down to around 30 degrees before you can put it through a floor matrix (imagine trying to walk on a floor heated to 70 degrees - yikes). Best low cost option is to stick to rads which work perfectly at higher temperatures and just need a simple low cost circulation pump.
No disadvantages to a tall exposed internal chimney - the only doubt with heating a tall room is that as hot air rises it will be a lot hotter at the top than at the bottom where you are and you may need to fan it or add a heat recovery system (another fun topic!)
These people supply a lot of interesting kit ... https://www.navitron.org.uk/ and have a lot of useful info on their site
Some useful info on in flue heating coil design here http://www.esru.strath.ac.uk/EandE/W...n-flue-hx.html
Its very important to find a way to insulate loft space a lot of heat is lost there
Carpets on top of UFH are not good as they stop the heat from warming the room. No need anyway as walking on a 30 degree heated floor is wonderful in bare feet.
Back boiler connected direct to UFH is no good as the temperature of the water is too high. You have to heat a large tank of water using an indirect coil to get the temperature right down to around 30 degrees before you can put it through a floor matrix (imagine trying to walk on a floor heated to 70 degrees - yikes). Best low cost option is to stick to rads which work perfectly at higher temperatures and just need a simple low cost circulation pump.
No disadvantages to a tall exposed internal chimney - the only doubt with heating a tall room is that as hot air rises it will be a lot hotter at the top than at the bottom where you are and you may need to fan it or add a heat recovery system (another fun topic!)
These people supply a lot of interesting kit ... https://www.navitron.org.uk/ and have a lot of useful info on their site
Some useful info on in flue heating coil design here http://www.esru.strath.ac.uk/EandE/W...n-flue-hx.html
Its very important to find a way to insulate loft space a lot of heat is lost there
Carpets on top of UFH are not good as they stop the heat from warming the room. No need anyway as walking on a 30 degree heated floor is wonderful in bare feet.