Radiator Booster - any thoughts?

don0301

zeupater wrote: »

An excellent example of illogical selective thinking and posting there. As others can plainly see and for total clarity to yourself, please consider the text which you have obviously intentionally excluded .....

"Effectively adding an equivalent level of insulation or airtightness to either a low internal mass or high internal mass structure would be similar to adding identical complexity to two sides of an algebraic equation, they would simply cancel each other out."

... which places the text which you quoted into context. Of course insulation is the paramount consideration in reducing building energy losses, however, insulation & thermal mass are two separate considerations when placing what whasup posted into context.

For simplicity, an analogy ..... take two identical teapots, fill both to the brim with boiling water and let the fabric of the teapots reach equilibrium with the water. What we have is two high mass structures, so we'll empty one pot, leaving one high mass uninsulated structure and one low mass uninsulated structure, both having the same initial temperature - which one cools fastest at room temperature ? ....... now lets repeat the above and immediately place a tea-cozy over each pot in order to provide an identical level of insulation - which one now cools first at room temperature ? ...... I understand that there is a counter argument that it requires more energy to raise the temperature of a high-mass structure to temperature, but comfort levels must also be taken into consideration.

HTH
Z

http://www.youtube.com/watch?v=gmOvEwtDycs&feature=related

don0301

zeupater wrote: »

Hi Ben

Our property was architect designed & specifically built with high integral thermal mass with the intent of maximising solar gain at low sun-angles and slow release storage of energy from solid fuel sources. Despite overnight temperatures around 0C and max temperatures today of ~5C we have only needed to have a late burn again today, so far around 5 hours, and there was absolutely no heating at all used yesterday. The house temperature in the hall this morning was 0.5C lower than yesterday morning.

I have a good friend with a low mass house which was designed & built utilising the very best practices which were around 15years ago (probably very close to current passivhaus standards) where the lack of thermal mass creates a condition where low angle insolation produces overheating at this time of year and we are both aware of the advantages & disadvantages of our respective builds ..... incidentally, the friend in question has recently completed and moved into a high thermal mass property and is leasing out the other one.

High thermal mass is also well suited to low intensity/low temperature heating such as provided by GSHP where the heating cycle which would in normal circumstances be serviced by a 30-40kW gas or oil source is extended to deliver the required heatload over a longer period by a 12-15kW HP unit.

Anyway, enough on thermal mass - I thought that the issue here is the effectiveness of strapping some PC forced ventilation fans to a radiator .....

HTH
Z

ok, we've established you are rich, with a very expensive designer built home, good for you.

I really fail to see how you bragging about it helps anyone on here?

or did I miss something?

don0301

zeupater wrote: »

Hi Ben

Our property was architect designed & specifically built with high integral thermal mass with the intent of maximising solar gain at low sun-angles and slow release storage of energy from solid fuel sources. Despite overnight temperatures around 0C and max temperatures today of ~5C we have only needed to have a late burn again today, so far around 5 hours, and there was absolutely no heating at all used yesterday. The house temperature in the hall this morning was 0.5C lower than yesterday morning.

I have a good friend with a low mass house which was designed & built utilising the very best practices which were around 15years ago (probably very close to current passivhaus standards) where the lack of thermal mass creates a condition where low angle insolation produces overheating at this time of year and we are both aware of the advantages & disadvantages of our respective builds ..... incidentally, the friend in question has recently completed and moved into a high thermal mass property and is leasing out the other one.

High thermal mass is also well suited to low intensity/low temperature heating such as provided by GSHP where the heating cycle which would in normal circumstances be serviced by a 30-40kW gas or oil source is extended to deliver the required heatload over a longer period by a 12-15kW HP unit.

Anyway, enough on thermal mass - I thought that the issue here is the effectiveness of strapping some PC forced ventilation fans to a radiator .....

HTH
Z

erm, you made a song and dance of it?????

zeupater

don0301 wrote: »

ok, we've established you are rich, with a very expensive designer built home, good for you.

I really fail to see how you bragging about it helps anyone on here?

or did I miss something?

Hi

We are very lucky to live in our property and it definately isn't as a result of privilege, what we have was worked hard for over many years and has absolutely no bearing on what I have ever posted. What I have posted is in order to to convey information which may be of use to others, in this case regarding the relative thermal performance of high and low mass high performance buildings, this being done because I have direct experience in high thermal mass, through having one, and a low mass building through a good friend. The fact that both buildings are architect designed is in reality just a poor reflection on the level of planning and design within the general building industry over the past number of decades, a situation which is just as true in large properties as it is in small.

You can continue to goad me and others as much as you like as this is an open forum, however, it's pretty plain to see that there is an unnecessary level of disruptive intent in your posting which seems to convey an agenda. Whatever that agenda may be doesn't particularly provide a cause of concern to myself and I would hope that many others who would hold similar views, however, the abrupt, abrasive and often abusive style of your posting only reinforces my view that the style of posting employed is consistent with what many classify as being serial trolling.

HTH
Z

Cardew

Z,
Don't feed the troll!

zeupater

Cardew wrote: »

Z,
Don't feed the troll!

Hi

Been trying not to for some time ... seems like others feed freely though ! ...

Anyway, back to forced air convection when related to twin panel radiators ....

I would have thought that placing plastic profiles at the top of a radiator would restrict convective airflow and therefore reduce radiator efficiency, therefore fitting a couple of low-power fans would need to match/reinstate the natural level of convective airflow before providing any benefit, with the benefit only being proportional to the additional volume of air passed between the panels as a result of the fans. This really raises the point that, for a given set of fans mounted at each end of the plastic profile, there must be reduction in efficiency gains (if any) as the length of the radiator increases ....

What I do know is that lighting a log burner after a few days of no usage initially has little effect whilst the stove and the surrounding masonry are absorbing the heat, however, to compensate for heat absorption when necessary we use an ionizing HEPA air filter with a ~50W fan to force convection vertically past stove surfaces heated to between 450F & 500F in order to spread the heat evenly for a while, this is particularly useful in mixing the cooler air at floor level and the warmer air clinging to the ceiling, therefore forced convection does work. However, considering that we use a ~50W fan against surfaces which are around five times warmer than a radiator leads me to wonder about how much short-term benefit a couple of small diameter PC fans strapped to a radiator could provide ....

HTH
Z

malc_b

Cardew wrote: »

No there is no misunderstanding on my part.

<snip>

However when challenged the EST admitted that they had misread the CERT guidance and that those annual savings(i.e. £6 or £3.50 for a whole house) only applied to houses with solid walls i.e. without cavity walls.


So EST have conceded that foil behind radiators in a house with insulated cavity walls hardly saves anything - perhaps a few pence per year.

Thank you for explaining your original post more fully. Interesting. Makes sense. What you're saying is a cavity, especially when filled, becomes a thermal break so most of the heat in the wall behind the radiator goes sideways and thus back into the room.

I've pasted foil behind my radiators when they have been removed, changed, or moved. I've probably saved the cost of the foil then

whasup

The biggest effect of foil behind a radiator will be that the radiator and return temperature will be (ever so slightly) hotter. I wouldn't mind betting the resulting loss of seasonal efficiency would outweight most if not all of the potential saving.

don0301

zeupater wrote: »

Hi

We are very lucky to live in our property and it definately isn't as a result of privilege, what we have was worked hard for over many years and has absolutely no bearing on what I have ever posted. What I have posted is in order to to convey information which may be of use to others, in this case regarding the relative thermal performance of high and low mass high performance buildings, this being done because I have direct experience in high thermal mass, through having one, and a low mass building through a good friend. The fact that both buildings are architect designed is in reality just a poor reflection on the level of planning and design within the general building industry over the past number of decades, a situation which is just as true in large properties as it is in small.

You can continue to goad me and others as much as you like as this is an open forum, however, it's pretty plain to see that there is an unnecessary level of disruptive intent in your posting which seems to convey an agenda. Whatever that agenda may be doesn't particularly provide a cause of concern to myself and I would hope that many others who would hold similar views, however, the abrupt, abrasive and often abusive style of your posting only reinforces my view that the style of posting employed is consistent with what many classify as being serial trolling.

HTH
Z

who cares about your big expensive architect designed house! it's just not relevant to most people! and why your trying to justify being a banker or whatever fabulously worthwhile career you think justifiably rewarded you, again /care

I agree with one thing, it has absolutely no bearing on the topic for most people! so why harp on about it?

I've stated insulation is much more relevant to most people than high thermal mass, in what way is that disruptive?

as to the rest of your Sir Humphrey nonsense....

don0301

zeupater wrote: »

Hi

Been trying not to for some time ... seems like others feed freely though ! ...

Anyway, back to forced air convection when related to twin panel radiators ....

I would have thought that placing plastic profiles at the top of a radiator would restrict convective airflow and therefore reduce radiator efficiency, therefore fitting a couple of low-power fans would need to match/reinstate the natural level of convective airflow before providing any benefit, with the benefit only being proportional to the additional volume of air passed between the panels as a result of the fans. This really raises the point that, for a given set of fans mounted at each end of the plastic profile, there must be reduction in efficiency gains (if any) as the length of the radiator increases ....

What I do know is that lighting a log burner after a few days of no usage initially has little effect whilst the stove and the surrounding masonry are absorbing the heat, however, to compensate for heat absorption when necessary we use an ionizing HEPA air filter with a ~50W fan to force convection vertically past stove surfaces heated to between 450F & 500F in order to spread the heat evenly for a while, this is particularly useful in mixing the cooler air at floor level and the warmer air clinging to the ceiling, therefore forced convection does work. However, considering that we use a ~50W fan against surfaces which are around five times warmer than a radiator leads me to wonder about how much short-term benefit a couple of small diameter PC fans strapped to a radiator could provide ....

HTH
Z

where the heat mostly rises up the wall, to the ceiling of a room...yeah, very efficient...