people still heat in April ...

[billi]

Hi skyewright

 the make is "Grammar solar"  a  German company

Billi

[skyewright]

the make is "Grammar solar"  a  German company

Thank you.

[EccentricAnomaly]

Earlier I wrote:

SSE? Seems ideal for homemade solar warm air to warm things up early in the day.  20 mm of insulation, some battens and double wall polycarbonate.

Should have mentioned the appropriately shaped absorber between the insulation and the polycarbonate, I suppose.

[billi]

I guess they have overdone it a bit      (Gemany)



he perhaps not..... with more style   (Holland)





this one  a clay house in a glasshouse  seems cool  (Germany)



Here is a video of the house above  http://www.youtube.com/watch?v=v2X6De1C_qU



still since years i cannot find, on the net, a picture of an old farmhouse in a greenhouse with lots of plants  that i saw once , the buyer decided to save some money from insulation and new window ,roof  etc and shifted  some towards a big glass house over the house

Somehow i like the idea if it is payable , to increase comfort and living space and  as well passively warm a solid /thermal mass house

Billi

[MarkB]

I guess they have overdone it a bit      (Gemany)

I can appreciate the benefits (if not the aesthetics) in winter but isn't overheating in summer a major problem?

[Baz]

The solarventi units seem a bit dubious. They are just a solar air heater with built in PV to drive a small fan. Sounds good but if the air is not heated above the inside temperature then the effect is to cool the house as there is no heat exchanger. At £500 for less than 1 m2 of collector it is rubbish. A window will collect the heat and a simple heat recovery ventillator will sort out the humidity problems they go on about.

[skyewright]

I can appreciate the benefits (if not the aesthetics) in winter but isn't overheating in summer a major problem?

Possibly, but there look to be opening vents along the full length of the ridge in the top and bottom pictures (in the bottom one they are all open). Judged on counting the rows of panes in the roof (4 rows of fixed panes, plus 1 row of opening, each side) that looks to be close to the ventilation recommended for a greenhouse (i.e. around 20% of the floor area?).

[qeipl]

Maybe part of the issue Billi's seeing is old stone or cob cottages with high thermal mass which haven't been heated [much] through the winter and spring and so need a lot of heat now to get up to temperature and dry out.

It's very noticeable in the old stone 1.5 story house i'm staying in now that the downstairs has been pretty chilly all the time even on the warmer days with its thick stone walls and concrete floor whereas the upstairs, which is much more thermally lightweight and has better windows, only really needs a pulse of heat in the morning until the sun starts to come in through the WSW facing main windows. You can feel the temperature drop running your hand down the handrail on the stairs.

I am unable to understand why the house was built in this orientation.

Most old houses (pre 1940s) in this part of the world were built with the gable facing the prevailing wind, presumably to minimise the draughts coming in around rattly case-and-sash windows and to stop the teacups from being blown off the table when opening the door.

[skyewright]

The solarventi units seem a bit dubious. They are just a solar air heater with built in PV to drive a small fan.

'expensive for what they are' rather than 'dubious'?

Sounds good but if the air is not heated above the inside temperature then the effect is to cool the house as there is no heat exchanger.

Perhaps the power rating of the PV panel & fan have been chosen to make that unlikely? If not then a fairly simple control logic would solve the problem. At least some of the units include a 'regulator', though it is not entirely clear what it does.

At £500 for less than 1 m2 of collector it is rubbish.

And the PV panel is 'inside' that area (which presumably means that it can get quite hot?).
I suppose there is the advantage of being a prepackaged "ready to fit" solution but the extra assembly for Navitron much better value SFG20's would not be great. However a lot of people are willing to pay a premium for "convenience", so there is probably a market (albeit, perhaps not among Navitron Forum users...).

A window will collect the heat and a simple heat recovery ventilator will sort out the humidity problems they go on about.

Would any of those run off a reasonably sized PV array?  Part of the Solarventi target market is ventilation of unoccupied properties where people might not like to leave a HRV unit running?.