Selection of alternate heating system

[Jeremy Harris]

7 minutes ago, coconutsaregood said:

 

Super efficient windows you have there. Are you using Perspex of something? That range is half of those made with coated mineral glass and inert gas cavities.

 

 

We have budget triple glazing that has a Uw of around 0.7 W/m².K.  The glazing units are mainly 4 - 20 - 4 - 20 - 4, with two low e coated panes and argon filling.

[Dan F]

We are going for:

 

- UFH downstairs (heating + cooling)

- No UFH/radiators upstairs

- Towel rails (probably electric in bathrooms)

- Our backup solution for upstairs is a VEAB unit connected to an insulated upstairs MVHR ducting, for minimal heating and cooling.

 

MVHR isn't a great way to heat/cool a standard house as you can't transport that much heat with standard MVHR duct sizes and flow rates, but with PH-standard levels of insulation where all you want is something supplementary we are expecting this to be quite effective.  (south-facing bedrooms will also have external venetian blinds, so cold air via MVHR won't be fighting the sun)

 

[coconutsaregood]

54 minutes ago, Jeremy Harris said:

 

 

We have budget triple glazing that has a Uw of around 0.7 W/m².K.  The glazing units are mainly 4 - 20 - 4 - 20 - 4, with two low e coated panes and argon filling.

 

I clearly need to go shopping for these things and not rely on the Table 16.47 of the Bldg Regs for U-values. Those large thermal breaks/multi-chambers on the most expensive windows are sure making a big difference to U-values. Thanks for your quick reply.

[GlynM]

14 hours ago, coconutsaregood said:

 

Super efficient windows you have there. Are you using Perspex of something? That range is half of those made with coated mineral glass and inert gas cavities.

 

I've gone with triple glazed Internorm windows, Home pure Timber/alu composites HF410 -  48mm coated clear glass Argon filled 4/18/4/18/4

[tonyshouse]

Great choice ? I used Xenon filled with solar capture low iron glass shaded in summer 

 

no heating system went slightly better with the U values - ten years on no regrets 

Edited April 15, 2020 by tonyshouse
Pressed return too soon

[jack]

On 13/04/2020 at 18:01, Jeremy Harris said:

It's only been up to 17°C here today, but plenty of sun, so the house is currently sitting at 23.5° with all three cooling systems running . . .

 

On 14/04/2020 at 18:15, Jeremy Harris said:

As I type this all three cooling systems are running again, the aircon in the bedroom, the floor cooling from the ASHP and the air cooling via the heat pump in the MVHR.  It was sub-zero here last night, too, with a hard frost.  Solar gain can be a real bugger at times.

 

No matter how many times it comes up, I'm always stunned by how much warmer your house gets in mild (chilly, even) sunny conditions in spring and autumn compared to ours, given we have the same construction type and comparable window U values. During those recent days of warm sunny weather, I doubt our house got much above 21-22°C, without any form of cooling on. 

[Jeremy Harris]

11 minutes ago, jack said:

 

 

No matter how many times it comes up, I'm always stunned by how much warmer your house gets in mild (chilly, even) sunny conditions in spring and autumn compared to ours, given we have the same construction type and comparable window U values. During those recent days of warm sunny weather, I doubt our house got much above 21-22°C, without any form of cooling on. 

 

 

It was a really big surprise to me, too, as well as being a damned nuisance!  The cooling systems operate for a lot longer every year than the heating system, not something I'd have ever envisaged when we were first planning the house.  I'm sure that a large part of it is due to our sheltered location, a combination of very little wind and a lot of exposure to the sun.  Right now the air temperature outside (taken on the sheltered North side of the house) is just 13.5°C, yet the kitchen (stone) window cills are warm and my wife's been sat outside in the garden for the past hour or so, without a coat.  Despite the cool weather and heavy rain yesterday morning, we still ended up turning the aircon on in the bedroom by late afternoon, as it was getting a bit too warm up there in the afternoon sun.  I really wish we'd been able to fit external blinds/shutters, or had opted for something like Sage glass, as I'm sure either would have made a world of difference.

[jack]

8 minutes ago, Jeremy Harris said:

It was a really big surprise to me, too, as well as being a damned nuisance!  The cooling systems operate for a lot longer every year than the heating system, not something I'd have ever envisaged when we were first planning the house.  I'm sure that a large part of it is due to our sheltered location, a combination of very little wind and a lot of exposure to the sun.  Right now the air temperature outside (taken on the sheltered North side of the house) is just 13.5°C, yet the kitchen (stone) window cills are warm and my wife's been sat outside in the garden for the past hour or so, without a coat.  Despite the cool weather and heavy rain yesterday morning, we still ended up turning the aircon on in the bedroom by late afternoon, as it was getting a bit too warm up there in the afternoon sun.  I really wish we'd been able to fit external blinds/shutters, or had opted for something like Sage glass, as I'm sure either would have made a world of difference.

 

The flip side, of course, is that we run our heating for much more of the year than you. And heating costs us money, whereas cooling is more or less free, given we only need it when the sun is shining...

[joe90]

I have always said the location of a build has a big impact on heat loss/gain and that is difficult to measure. When I said I was building a south facing conservatory on my build I was told we would cook in summer but because we very often have winds in a flat landscape  (and large openable windows) the chill factor is welcome. The west bedroom (no heating) is definitely cooler than the East bedroom (no heating) by a couple of degrees because of the wind wash. I have bought greenhouse netting to hang in the conservatory roof to stop the plant’s burning during the height of summer. (Hopefully ?). Apart from the depths of winter our house is heated by the conservatory and is controlled by opening and closing the two sets of bi folds into the house.

Edited May 1, 2020 by joe90

[Stones]

24 minutes ago, joe90 said:

I have always said the location of a build has a big impact on heat loss/gain and that is difficult to measure. 

 

Absolutely, The past month (and some days before) we have had internal house temps getting up to 24C (ambient air between 10 and 12C).  Our house is orientated south west so gets the benefit of the sun most of the day, when it is out.  As the sun rises in the sky over the summer, we don't generally see temps going as high inside,simply on the basis that the sun doesn't penetrate as far into the house. We almost always have a cooler air temp and breeze to help cool / regulate if required (with the exception of a couple of summers ago when air temp was a glorious 25C).  I spent a fair bit of time trying to model our specific heat loss / gain by factoring in wind generated heat loss and solar gain, and I think got a pretty accurate model as borne out by what we experience.  Determining the impact of solar gain, both average and peak, was fairly straight forward and identified what our cooling requirement was.  

[ProDave]

I am really looking forward to the time we can get the windows in the sun room.  Apart from a nice place to sit, part of it's objective is to catch solar gain to help heat the house.  It will be nothing more high tech than if it's warmer in the sun room, we open the connecting doors to let the heat into the house.  Shut them if it's too hot.

 

We also have the natural filter than as soon as the leaves grow on the trees, we stop getting much sunlight so a natural way to reduce summer overheating.

 

The only time we got too hot and needed some cooling was last years heat wave.  That was not excess solar gain but the air temperature got too high for too long and there is only so long good insulation can keep excess heat out from that.