Juleskitoo

Hello,

I'm currently converting a two story garage to residential use in Porto and i'll be honest I'm not completely sure of the method to heat the place. I was going to replicate what I had in my house in the UK and go the air source heat pump with underfloor heating but I gather this is probably not the best system to use as it takes a while to build up heat and I'd probably need something a bit more responsive as I'm only topping up the heating in winter.

Then I thought about electrical heaters on the walls (running on cheaper night time heating - is this a thing in Portugal?) backed up by a wood burning stove (as much as a focal point, but could understand that this maybe not strictly be needed?).

But I also need some summer cooling so thought of air conditioners (I gather some are reversible and can provide heating as well).

What ever I choose, it needs to be 'green' - I am planning on having some photovoltaics on the roof which should help costs but I doubt there is an equivalent to the feed in tarrif (but happy to be corrected).

PS I plan to have the building fully-insulated with double glazing.

Any suggestions of what you guys use/recommend would be really appreciated.

Many thanks,

Jules

dingg

If its not cost prohibitive I'd stick with your original idea of ashp tied into underfloor, just set it up to 21 degrees and forget about it.

Doubt you'll get much use out of aircon tbh, so would pass on that idea.

Next if underfloor out of the question would be pellet burner, if your space is reasonably small just to air, if bigger to radiators and possibly hw too.
Eta

House we bought was radiators heated from lpg and hw from same, very expensive to run. Plus a recuperater wood burner in lounge.
We have fitted a pellet stove in the lounge which kicks out a few kW to the lounge and the rest to the rads. Hw continues to be from the lpg combi.

If your going solar stick some panels up there tied into a store for both hw and heating maybe the best solution.

macliam

I'd also suggest the air-source heating.but there seems to be a blurred line between that and some reversible A/C....

Use what space you have for solar water heating, not photovoltaic...... the feed-in tariff isn't great and battery storage is expensive.

Make sure you have first class insulation - that'll help more than the heating source......

coleio

Hi,
Just a question - is the garage conversion part of your existing abode as you write
"I'd probably need something a bit more responsive as I'm only topping up the heating in winter"
suggesting there is some existing heating ?

liveaboard

If you go for underfloor water heat tubing, your system can be easily refitted to whatever source of heat is cheaper in future.
If you're pouring new floors, do it for sure.

Reversible AC is an air to air heat pump with an AC function. We use our AC for sleeping in summer, and it's great during allergy season.

Juleskitoo

Hi,

No, its just a garage at the moment. My comment was an assumption that in Porto I'd only need heating thru the winter - but I could be wrong on this!

Juleskitoo

Thanks - I'll investigate the ASHP and ACs - interesting that no one is really saying I definitely need an AC. And like you I'm on board with the importance of good quality insulation.

Juleskitoo

Thanks Dinng, lots to consider in your reply. Is a recuperater wood burner one linked to the heating in some way? I do have plenty of space so could consider a pellet burner. And sounds like a wood burning stove is not entirely a ridiculous idea in Portugal - I like them as they provide a focal point to the room.

Juleskitoo

Appreciate the reply - so the tricky thing is I'll only be pouring the downstairs floor - I was considering piping the UFH upstairs to radiators (not brilliantly effective from prior experience but hopefully topped up by the wood burning stove -which will be upstairs)

Are you based in Porto (I know Portugal is variable weather-wise) - just wondering how important ACs are for Porto itself. And can they be used to power a wet UFH system?

dingg

Hi

Mine isn't connected to the heating system, but has a twin speed fan that recovers heat that would be lost to the chimney and puts that into the room, good focal point, and once it gets going heats up the room very well, we also have the pellet stove in the same room and that heats the whole house.

You won't need ac in porto imo.


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liveaboard

No, I'm on the west coast down south.
Reversible AC is air output only.
Be aware that the numbers in advertisements for 'heat pump' systems are usually based on some very optimistic variables. As the temperature difference increases, their efficiency decreases. so if you have cold air outside, they don't work cheaply. They'e just big AC machines, pumps with fluid and fans.

You won't need a huge amount of heat if you're well insulated.

macliam

Is this a permanent residence? Heat sources that take time to have an effect may be more efficient, but less comfortable in a property left empty for any time.

My house in the Alentejo is Taipa, naturally warm in winter, cool in Summer - an older extension is like a fridge in winter, but a new extension (to the current insulation standards, double block and foam) is even better than the Taipa. It's hard to know how much extra heating/cooling you'll need after that. However, if retro-fitting into an existing building, it may not be easy to reach that level of insulation.

If pouring a floor, add the tube infrastructure..... the cost is minimal for the flexibility offered - but air-to-air may be your best solution overall.

A woodburner or back-burner fire is a possibility - it can quickly heat a confined space and water heating or heat recovery is an option. This means you need to add in a fireplace/chimney - a good focal point even if you don't use it. Pellets are popular, but they are a manufactured fuel, so the current low price can change (like oil did). If going for radiators, pay for good aluminium ones for best heat transfer... especially with lower water temperatures.

The solar water heating is a no-brainer, but again there may be an initial lag if the property is unoccupied for any time (panels may need covering to avoid overheat).

I'd say build with the ability to change later - pre-prepare for underfloor, radiators and A/C - running pipes is a lot cheaper at build time! (run extra electricity outlets and build in CAT-5 too) Then get the best level of insulation you can manage (incl, draught prevention) and live the first period without any extra heat source or cooling (electric heating is cheap to buy). After that, you will know what you need for your comfort and can add-in the required sources. Connecting A/C etc. to existing pipework and a power supply is simple.

Rosemary

Hi Folks

I think that I have managed to sort out the mess up with the quotes. If one is wrong it causes all that follow on to be messed up and that was what happened.

Stay safe

Rosemary

Juleskitoo

Thanks, appreciate the reply.

wellinever

Modern AC fixed units are very efficient. Always immediate heat . Get minimum A++ hot and cold. Other benefits fan only and dehumidify.
Insulate the floor with min 4cm Floormate or equivalent. If digging out floor, also use Leca Balls in any concrete screed for added insulation.