solar - tubes or panels??

8vSport

hi all

we are going to put a solar panel in our new build. we had a couple of people out already and half are saying to go for tubes and the other flat panel?

just wanted to ask people for the opinions if they have them in their own house?

thanks

muffler

Moved to RE sub forum

quentingargan

A quick summary;

Flatplate Pros
Aesthetics - I would use roof integrated which will be no more conspicuous than a Velux window.

Durability (40 to 45 years). Tubes will have to be replaced after about 20 years, though some tubes (Chinese flask type) are very cheap to replace.

Probably can survive a hurling family. (Though if kids do break a flatplate, they're in deep ....)

Tubes Pros
More efficient in the fringes of the season - spring and autumn. If the house is well insulated, and the heating is off for a lot of the year, this is a distinct advantage.

Will also provide more consistent production on cloudy days.

It really is a matter of taste. Flatplates are simpler, and usually can be installed without a heat dump. You may also find that because of fundamental flaws in the software used by BER assessors, if your house is very large, it may be difficult for some tube systems to meet Part L of the building code. However, flatplates produce more heat on hot days and less heat on cloudy ones. Tubes provide a more balanced output.

Personally to increase the longevity of either system, I would always prefer to use a heat dump by the way....

RTT

quentingargan wrote: »

A quick summary;

Flatplate Pros
Aesthetics - I would use roof integrated which will be no more conspicuous than a Velux window.

Durability (40 to 45 years). Tubes will have to be replaced after about 20 years, though some tubes (Chinese flask type) are very cheap to replace.

Probably can survive a hurling family. (Though if kids do break a flatplate, they're in deep ....)

Tubes Pros
More efficient in the fringes of the season - spring and autumn. If the house is well insulated, and the heating is off for a lot of the year, this is a distinct advantage.

Will also provide more consistent production on cloudy days.

It really is a matter of taste. Flatplates are simpler, and usually can be installed without a heat dump. You may also find that because of fundamental flaws in the software used by BER assessors, if your house is very large, it may be difficult for some tube systems to meet Part L of the building code. However, flatplates produce more heat on hot days and less heat on cloudy ones. Tubes provide a more balanced output.

Personally to increase the longevity of either system, I would always prefer to use a heat dump by the way....

Do you have much experience with the<SNIP> From what I read they don't require a heat dump as they have a built in temperature limitation safety feature. I have decided to go for the evacuated tubes but not sure which type as of yet. I'm leaning towards <SNIP> however and just for the record I have no links to <SNIP> whatsoever.

Outkast_IRE

RTT wrote: »

Do you have much experience with the Kingspan Thermomax range? From what I read they don't require a heat dump as they have a built in temperature limitation safety feature. I have decided to go for the evacuated tubes but not sure which type as of yet. I'm leaning towards Kingspan however and just for the record I have no links to Kingspan whatsoever.

the <SNIP> tubes are great , and yup no need for heat dump in heat pipe versions . The quality is excellent.
However some people would see the downside with these tubes as the high cost to replace tubes vs cheaper chinese tubes.
One thing you will find with people talking about solar everyone will have their own opinion , personally if i had the money i would install <SNIP>.

saibhne

Outkast_IRE wrote: »

the thermomax tubes are great , and yup no need for heat dump in heat pipe versions . The quality is excellent.
However some people would see the downside with these tubes as the high cost to replace tubes vs cheaper chinese tubes.
One thing you will find with people talking about solar everyone will have their own opinion , personally if i had the money i would install the thermomax.

In deference to the rules, I'll leave out the brand names here.

There are tubes that have a valve in the heat pipe which prevents fluid in the solar circuit rising above a certain temperature - 95 degC in the most common model. So you will never get the panel going into stagnation. However, when this valve is closed, the internals of the tube continue to heat up, reaching temperatures well above 200C. Repeated incidences of this are not good for the seal which keeps in the vacuum.

Because of this the manufacturers say that the way they size the system is the primary method of avoiding stagnation and not the valve which is secondary. Relying on the valve alone will eventually get you into trouble IMO. So, if you are using this type of system, it is usually recommended that you only use a limited number of tubes per 100L of water in your cylinder. This limits the overall energy yield of the system making it produce similar amounts of energy to lots of other systems on the market.

Having said that the panels are made in Portadown which is Irish if you are of the 32 county persuasion.. The company is listed on the Irish and London stock exchanges so there is a foot in both camps. The panels are well made and come with a 20 year warranty if installed by a recognised installer. But they are relatively expensive to buy and will be expensive to replace in case of breakage/end of life.

muffler

I have unapproved 2 posts for now. I'll have a talk to my co-mods about this and revert.

muffler

Okay then guys. I have done a little editing of the 2 posts above (by RTT and Outkast_IRE) and removed reference to the product name and manufacturer. No harm done as such but if you look at the other 2 most recent posts by saibhne and quentingargan you will see that it is possible to discuss the various types of products without mentioning trade/manufacturer's names.

I discussed this matter with the other forum mods and we were all in agreement that posts should conform with the forum charter. I accept that there was no attempt by anyone here to promote or shill a particular product but its only fair that we keep a level playing field and that can only be achieved by not making reference to a specific manufacturer as that could result in that firm gaining a slight advantage or perhaps could result in some not so nice comments being made on occasions.

Thanks for your patience guys.