Do I really need a brise soleil?

[Gone West]

Before we move into our house last year I had designed a brise soleil to shade our lift slide doors which are the only south facing glazing we have. Needless to say I never actually made it and having lived in the house for the first summer and now winter I’m not sure it’s needed. We had a nice lot of solar gain recently which meant there was no heating on in the house. IIRC last summer the sun only penetrated around 600mm into the room on the floor. I’ve run the software linked to by @Cambs and results suggest I would lose too much solar gain when I need it from October to February. Any comments? The doors are shaded completely before 12.00.

 

 

 

Edited March 3, 2019 by PeterStarck

[Jeremy Harris]

I think the key bit is that the doors are shaded by midday.  I've found that most of the solar gain through our overhead shaded front glazing is from around 11:00 to about 15:00.  From the  data above I'd say that it looks very much as if you don't really need the brise soleil.

[epsilonGreedy]

Have you missed the 5 for fifty when entering the latitude?

 

Edit: The latitude of Canterbury is 51.2802° N

Edited March 3, 2019 by epsilonGreedy

[ToughButterCup]

Yeah, you do.  

Grow roses and a wisteria over in and through them.  

[Gone West]

18 minutes ago, epsilonGreedy said:

Have you missed the 5 for fifty when entering the latitude?

Isn't that longitude. I think the North refers to hemisphere. No you're right it should be 51.292297.

Edited March 3, 2019 by PeterStarck
I'm a donk

[Jeremy Harris]

9 minutes ago, PeterStarck said:

Isn't that longitude. I think the North refers to hemisphere.

 

You can check lat. and long. using this tool: https://www.latlong.net/

 

Very roughly I'd expect you to be somewhere around 51.3°N, 1.3°E (lat. and long. respectively).

[Gone West]

Well having the correct data makes all the difference. Thanks @epsilonGreedy that'll teach me to cut and paste without checking. Wendy won't be happy but it looks like we will need one after all. It now looks more like I expected it to.

 

 

 

 

[epsilonGreedy]

3 minutes ago, PeterStarck said:

Isn't that longitude. I think the North refers to hemisphere.

 

 

Pretty sure it wants latitude to calculate the elevation of the sun for each hour per month. You would then need to fiddle the numbers for your local noon which is a small adjustment, about 5 minutes I guesstimate for your part of Kent.

 

The high degree of shading shown in the OP with your default overhang looks about right for khartoum.

[epsilonGreedy]

3 minutes ago, PeterStarck said:

Well having the correct data makes all the difference. Thanks @epsilonGreedy

 

 

Having sailed north and south across 50 degrees of latitude many times i.e. the English Channel these numbers are fused into my brain. 

[Gone West]

I've been told I can't start making a brise soleil until the garden is finished. We won't need one by the time that's done.

[Jeremy Harris]

Makes a big difference having the right lat.! 

[vivienz]

But surely, if you have lived in the house for a year now, and given how long and not last summer was, the real life experience overrides all the software modelling? If you didn't fry yourselves last summer then is it really necessary?

[Gone West]

18 minutes ago, vivienz said:

If you didn't fry yourselves last summer then is it really necessary?

That's Wendy's argument. Wendy didn't fry, 26/27C is comfortable for Wendy. Anyway it looks like I'll have another summer to consider it as it will take some time to finish the garden.

[Sue B]

How about buying a garden sail to shade the window this summer and see how this works without spending money or time designing something “proper”.  You can even put it up and down a few times to help your decision making process.  Modelling is all well and good but real life is sometimes different.

Edited March 3, 2019 by Sue B

[newhome]

1 hour ago, PeterStarck said:

That's Wendy's argument. Wendy didn't fry, 26/27C is comfortable for Wendy. Anyway it looks like I'll have another summer to consider it as it will take some time to finish the garden.

 

Jeez, I fry at around 24 degrees which is what it got to in here in the heat of the day last summer. Agree with @Sue B. Have a play with some temporary shading with the use of sails or a gazebo to see what's ideal, then fit something without any guesswork.  

[MikeSharp01]

One thing I noticed last week was how much the additional penetration makes in solar gain terms into our garden room, 24deg West of south, in the winter when the sun is maxing out as it was last week.

 

It has a brise soleil which works in the summer but it was overheating badly last week.

[Jeremy Harris]

Just now, MikeSharp01 said:

One thing I noticed last week was how much the additional penetration makes in solar gain terms into our garden room, 24deg West of south, in the winter when the sun is maxing out as it was last week.

 

It has a brise soleil which works in the summer but it was overheating badly last week.

 

 

Exactly our issue, something I first noticed the Spring after the house went up.  The house is fine in midsummer; it's always Autumn and Spring that cause the problems.  Our cooling system came on for four days last week, each time it was at no cost (generation exceeded consumption by a lot), but I'd rather the heat didn't get in in the first place.