Concerned about solar heat gain

[Bancroft]

23 hours ago, flanagaj said:

do these 'fan coils' require some sort of condensation drain.

I'm still investigating this and haven't yet fitted so take read this with caution.

 

Condensation drains? I think the basic answer is 'yes'.

 

However, if thought about early enough in the planning process it shouldn't be too much of an issue.  I'm planning on 4-5 fan coil heads in a single storey building and (on paper) it doesn't seem too torturous to find ways to locate the fan coil where drains will be easy to install.  For example, we have two bedrooms with a bathroom in the middle - easy to mount the units on the bathroom/bedroom wall and take the drain through the wall into the bathroom plumbing.  Ditto near the kitchen etc.

 

Also, I think some units that can be ceiling mounted can pump condensate uphill to then flow down into the final drain.  This means easier installation between floors or routing through loft spaces.

[JohnMo]

18 minutes ago, Bancroft said:

I'm still investigating this and haven't yet fitted so take read this with caution.

 

Condensation drains? I think the basic answer is 'yes'.

 

However, if thought about early enough in the planning process it shouldn't be too much of an issue.  I'm planning on 4-5 fan coil heads in a single storey building and (on paper) it doesn't seem too torturous to find ways to locate the fan coil where drains will be easy to install.  For example, we have two bedrooms with a bathroom in the middle - easy to mount the units on the bathroom/bedroom wall and take the drain through the wall into the bathroom plumbing.  Ditto near the kitchen etc.

 

Also, I think some units that can be ceiling mounted can pump condensate uphill to then flow down into the final drain.  This means easier installation between floors or routing through loft spaces.

As soon as you flow water below dew point (let's say 12 degs) for more than a few minutes you will start to generate condensation. Target flow temps below dew point, you get condensation forming. Our summer house has a fan coil and have never seen a single drip from it. It flows from the same circuit as the house UFH.

[Nick Laslett]

On 02/07/2025 at 11:55, flanagaj said:

…do these 'fan coils' require some sort of condensation drain?

MVHR, A/C and ComfoPost all need condensate drains,
 

The planning and installation of all this stuff is where the professionals can really add their value.

 

Many different ways to route all this stuff, but really helps if you design it in from the beginning. Same with the external blinds. Just look at villas in Provence or Tuscany, they all have thick stone walls, small south facing windows with external timber shutters. 
 

If you can design in motorised external shutters, this would solve this problem. Won’t suit all house styles. 
 

Good video on this topic. 
 

 

Edited Thursday at 11:27 by Nick Laslett

[Bramco]

19 hours ago, flanagaj said:

All of these suggestions are great, but they all seem to come at a ridiculous cost and given we are already struggling to balance the numbers it just keeps spiralling.  We have been told that Solar glass is an 8% uplift so that is probably the cheaper option than fittings the blinds or AC/PV

Talk to Hallmark Blinds - I can't remember what ours cost but it wasn't prohibitive.  And you don't need anything fancy for the 'cassette' that the blinds park into when up. All you need is a properly sized gap behind the cladding, so that the blinds can be fitted into the gap.

[Thorfun]

20 hours ago, flanagaj said:

All of these suggestions are great, but they all seem to come at a ridiculous cost and given we are already struggling to balance the numbers it just keeps spiralling.  We have been told that Solar glass is an 8% uplift so that is probably the cheaper option than fittings the blinds or AC/PV

external blinds will mean you won't need internal curtains so the total cost is reduced when you consider that

 

speak to an AC company about costs for getting them to do first fix and then you can second fix at a later date when funds allow

 

there are ways to reduce the initial outlay of costs and some costs can be offset by mitigating the need for other things later. e.g. adding solar PV now will reduce the running costs of the house as you live in it. so you're, in essence, buying your electricity up-front until you get to the point that you've paid off the install and then you're getting free electricity!

[flanagaj]

6 hours ago, Bramco said:

Talk to Hallmark Blinds - I can't remember what ours cost but it wasn't prohibitive.  And you don't need anything fancy for the 'cassette' that the blinds park into when up. All you need is a properly sized gap behind the cladding, so that the blinds can be fitted into the gap.

Interesting product, but keen to understand the build up for a traditional masonry build with timber cladding.  The vertical timber cladding sits on two 25mm battens, so to have the blind hidden when open, will require an interesting and unconventional opening?

[flanagaj]

I came across these last night.  They look very good for bedrooms and are exactly what they fit on the continent.

External Roller Shutters | Enviroblinds

[Thorfun]

5 minutes ago, flanagaj said:

I came across these last night.  They look very good for bedrooms and are exactly what they fit on the continent.

External Roller Shutters | Enviroblinds

We went with Venetian so you can still see out while shading. 
 

https://www.hallmarkblinds.co.uk/external-blinds-and-shutters-uk

 

the Trojan ones. 

[flanagaj]

4 minutes ago, Thorfun said:

We went with Venetian so you can still see out while shading. 
 

https://www.hallmarkblinds.co.uk/external-blinds-and-shutters-uk

 

the Trojan ones. 

I will look at the Venetian offering.  Given it is just for the bedrooms, having them closed during the day is ok.  For us, it will come down to cost.

[Thorfun]

41 minutes ago, flanagaj said:

I will look at the Venetian offering.  Given it is just for the bedrooms, having them closed during the day is ok.  For us, it will come down to cost.

Sure. Cost is important. But so are aesthetics! I think there are so many factors to consider. 
 

it’s one of the reasons self-building is so stressful. All the decisions that need to be made from loads of various data points. 

[-rick-]

1 hour ago, flanagaj said:

I will look at the Venetian offering.  Given it is just for the bedrooms, having them closed during the day is ok.  For us, it will come down to cost.

 

I've seen a thread on here in the past about how the insect screens they had installed ended up being about perfect for shading too. Relatively cheap (as its simple roller blind) and maintains the view while cutting a lot of light. There are probably downsides too but worth considering as they will serve a dual purpose (though you will need curtains too if you want to black out the room).

[flanagaj]

One other question I have regarding the venetian or roller blinds is how they perform when it's windy.  Ideally, we would use them to black out the room and remove the need for curtains.   But this obviously only works if they don't rattle when it's blowing a gale straight at the window.

[Thorfun]

46 minutes ago, flanagaj said:

One other question I have regarding the venetian or roller blinds is how they perform when it's windy.  Ideally, we would use them to black out the room and remove the need for curtains.   But this obviously only works if they don't rattle when it's blowing a gale straight at the window.

One year in and no issues with this so far.