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Solar Thermal....Bamboozaled... please help

  • 14-05-2019 8:53am
    #1
    Registered Users Posts: 500 ✭✭✭ oakshade


    Hi all,
    I've a few euro put aside with the intention of installing solar thermal. I'm getting lots of conflicting advice and I'm hoping this group can point me in the right direction.

    Note, my house is east-west which is causing a lot of the issues
    • My family plumber told me my budget would buy a lot of heating oil!
    • A recommended plumber from a local plumbing supplies told me solar thermal is dead and thermodynamic is the way to go. He quoted me 6k! A thermodynamic only company quoted me 4.5k
    • One solar installer is recommending tubes front and back of the house due to east/west position. This is over budget
    • One company is recommending 40 tubes only on the rear of the house (west).
    • One company is recommending panels on the rear of the house (west). This is the cheapest quote.

    I dont want to spend money foolishly, it's too hard to come by... I'm open to your experiences, particularly if your home is east/west and also to recommendations (if allowed by mod, if not apologies).

    Thank you!

    EDIT - household of 2 adults and 2 kids, nearly every company is recommending 300L hot water tank


Comments

  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    Good one...

    So you want solar tubes for hot water only !?
    Whats your current heating source ?
    I will go with 20 tubes on the east and 20 tubes on the west.
    Easy to assemble / connect at the mixer level on the roof.
    They are right to quote cylinder 300l.

    How big is the roof,any obstructions,shadows,houses near by ?
    Whats your electricity consumption over 12 months ,over a week and over a day ,any patterns or figures may help to determine if the full roof may take a 7 plus 7 PV panels and it could do the job nicely with a a diverter.


  • Registered Users Posts: 500 ✭✭✭ oakshade


    rolion wrote: »
    Good one...

    So you want solar tubes for hot water only !?
    Whats your current heating source ?
    I will go with 20 tubes on the east and 20 tubes on the west.
    Easy to assemble / connect at the mixer level on the roof.
    They are right to quote cylinder 300l.

    How big is the roof,any obstructions,shadows,houses near by ?
    Whats your electricity consumption over 12 months ,over a week and over a day ,any patterns or figures may help to determine if the full roof may take a 7 plus 7 PV panels and it could do the job nicely with a a diverter.

    Solar tubes for hot water only, yes
    Current heat source is oil
    The company that quoted me for tubes back and front were 1500 more expensive than tubes only at the back. They cited extra pump and equipment. Ultimately there may have been additional tubes too, they didn't say.

    Roof is huge, steep pitch (dormer), multiple velux at back but plenty of space. No obstructions, shadows - once off house in the country.

    I hadn't considered pv, I don't believe my budget will go to it.

    Appreciated, thank you!


  • Registered Users Posts: 13,369 ✭✭✭✭ loyatemu


    It was noted in the PEV pricing thread that solar tubes have a lot more moving parts and things to go wrong compared to PEV. Would PEV with a diverter be an option?


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    oakshade wrote: »
    Solar tubes for hot water only, yes
    Current heat source is oil
    The company that quoted me for tubes back and front were 1500 more expensive than tubes only at the back. They cited extra pump and equipment. Ultimately there may have been additional tubes too, they didn't say.

    Roof is huge, steep pitch (dormer), multiple velux at back but plenty of space. No obstructions, shadows - once off house in the country.

    I hadn't considered pv, I don't believe my budget will go to it.

    Appreciated, thank you!


    Nice one,take advantage of the space and no nosy neighbours around.

    I'm going to be biased as i have both systems working for the past few years.
    PVs are great for electricity and excess diverted to cylinder.Zero maintenance once they are fitted properly.
    Solar tubes performs much better only for water with a note for maintenance every couple of years.

    Solar tubes are not entirely designed to heat the water at maximum temperature so that you can shower or bath. This happens only in the real warm days, i'll say April to October (no heating the water at all these months). The remaining months,it will just bring it from 10ish (main pipe' supply temps) all the way up until the boiler can kick it and work more efficient to bring it to a decent 50ish. This way,boiler works less harder, less consumption, more advantages for your pocket.

    My advice is to drive to Dublin,in ParkWest and call in to Joule's showroom.
    They have there lots of panels and systems for show and training.
    Talk with one of their presales / technical guy and see what they can offer ,what they say.
    The office will not be able to sale you directly, neither to point you to a reseller or installer. But you get the ideea from the manufacturer. There are a lots of DIY / building materials shops that sells the kit in 20 + 20 tubes and all the accessories.You just pay upfront,your cash,you control the delivery.
    Then,is just a matter to get a SEAI approved installer and i reckon in a day is gone and tested / grant signed.

    For solar tubes,you get a massive grant as well.Check SEAi website.Apply for grant before any purchase and you can select whatever installer you like of that list, based on your location.It has to be approved otherwise no grant application signed,no money back to you ! I got i think €1,900 back (with a forth grant bonus).

    I will say go for 20 and 20 tubes or as much as you can afford,price and space. As a cylinder,for every 10 tubes on the roof you will need 100L of cylinder space.
    Get a variable speed pump and a RESOL controller not a particular locked in supplier type. With RESOL, you can replace it easy free market, you can customise it and remotely mobile app monitor the whole system. Even send you email alerts if temperature too high or too low !!!

    Instalallation,agreed with your materials, just get the approved installer at a day rate labour. Joule will deliver all the parts to your address a day before and ... enjoy it !

    For PV panels,as well, easier to fit than tubes.
    You get the advantage of free electricity and divert excess to hot water cylinder.
    There are grants for PVs and if you read the thread below,you will get quotes and feedback from end users.
    To cover house base load adn have cylinder as a priority,i will say go fo rminimum 4Kwp installed,that will assure you 3Kw for diverter an remaning for house.

    Now,keep in mind that there are days when solar tubes will warm up the water to mid 30ish while the PVs will keep only the inverter warm,in same day,time and location.This is due to how God Sun works his magic with UV and rays and photons hitting the panels / tubes and being converted,more or less efficient,to the end product,water or electrons. I was so upset during the winter times that the tubes will not warm up the water,even called in their offices to chat about it. Wanted to upgrade to a 40 tubes. Being told that winter is normal while summer is worrying about excess / diverting emergency high temperatures. And,they were right, after almost 3 years using the tubes,no problems.

    PLEASE note that i dont work for any one involved in the industry, i just shared my DIY experience here.
    loyatemu wrote: »
    It was noted in the PEV pricing thread that solar tubes have a lot more moving parts and things to go wrong compared to PEV. Would PEV with a diverter be an option?

    As explained above,yes, it will be better from an installation and maintenance cost but solar tubes are excellent for converting photons to hot water (as the OP requested).
    For PVs to do same,it will need a minimum 4-5KWp installed power and a diverter.

    For absolutely same day,PVs will warm the inverter rather than the water while tubes will get the pump kicking and moving the agent inside the piping.

    And with both systems subject to a decent SEAI grant,to be honest with you .. .WHY not go for both !?


  • Closed Accounts Posts: 18,277 ✭✭✭✭ Jamie Orange Cradle


    rolion wrote: »
    Nice one,take advantage of the space and no nosy neighbours around.

    I'm going to be biased as i have both systems working for the past few years.
    PVs are great for electricity and excess diverted to cylinder.Zero maintenance once they are fitted properly.
    Solar tubes performs much better only for water with a note for maintenance every couple of years.

    Solar tubes are not entirely designed to heat the water at maximum temperature so that you can shower or bath. This happens only in the real warm days, i'll say April to October (no heating the water at all these months). The remaining months,it will just bring it from 10ish (main pipe' supply temps) all the way up until the boiler can kick it and work more efficient to bring it to a decent 50ish. This way,boiler works less harder, less consumption, more advantages for your pocket.

    My advice is to drive to Dublin,in ParkWest and call in to Joule's showroom.
    They have there lots of panels and systems for show and training.
    Talk with one of their presales / technical guy and see what they can offer ,what they say.
    The office will not be able to sale you directly, neither to point you to a reseller or installer. But you get the ideea from the manufacturer. There are a lots of DIY / building materials shops that sells the kit in 20 + 20 tubes and all the accessories.You just pay upfront,your cash,you control the delivery.
    Then,is just a matter to get a SEAI approved installer and i reckon in a day is gone and tested / grant signed.

    For solar tubes,you get a massive grant as well.Check SEAi website.Apply for grant before any purchase and you can select whatever installer you like of that list, based on your location.It has to be approved otherwise no grant application signed,no money back to you ! I got i think €1,900 back (with a forth grant bonus).

    I will say go for 20 and 20 tubes or as much as you can afford,price and space. As a cylinder,for every 10 tubes on the roof you will need 100L of cylinder space.
    Get a variable speed pump and a RESOL controller not a particular locked in supplier type. With RESOL, you can replace it easy free market, you can customise it and remotely mobile app monitor the whole system. Even send you email alerts if temperature too high or too low !!!

    Instalallation,agreed with your materials, just get the approved installer at a day rate labour. Joule will deliver all the parts to your address a day before and ... enjoy it !

    For PV panels,as well, easier to fit than tubes.
    You get the advantage of free electricity and divert excess to hot water cylinder.
    There are grants for PVs and if you read the thread below,you will get quotes and feedback from end users.
    To cover house base load adn have cylinder as a priority,i will say go fo rminimum 4Kwp installed,that will assure you 3Kw for diverter an remaning for house.

    Now,keep in mind that there are days when solar tubes will warm up the water to mid 30ish while the PVs will keep only the inverter warm,in same day,time and location.This is due to how God Sun works his magic with UV and rays and photons hitting the panels / tubes and being converted,more or less efficient,to the end product,water or electrons. I was so upset during the winter times that the tubes will not warm up the water,even called in their offices to chat about it. Wanted to upgrade to a 40 tubes. Being told that winter is normal while summer is worrying about excess / diverting emergency high temperatures. And,they were right, after almost 3 years using the tubes,no problems.

    PLEASE note that i dont work for any one involved in the industry, i just shared my DIY experience here.



    As explained above,yes, it will be better from an installation and maintenance cost but solar tubes are excellent for converting photons to hot water (as the OP requested).
    For PVs to do same,it will need a minimum 4-5KWp installed power and a diverter.

    For absolutely same day,PVs will warm the inverter rather than the water while tubes will get the pump kicking and moving the agent inside the piping.

    And with both systems subject to a decent SEAI grant,to be honest with you .. .WHY not go for both !?
    Good post.
    Can you explain 20+20?

    Is there not a limit on only getting 1 grant. Thought you couldn't get another one for the same house.


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  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    Good post.
    Can you explain 20+20?

    Is there not a limit on only getting 1 grant. Thought you couldn't get another one for the same house.


    I gave an example of a setup on both roofs, east - west.
    You can combine a same number of tubes.
    20 tubes on east with 20 on the west gives you 40 evacuated tubes with a 300l cylinder.
    You can do 10,20 or 30 as a single unit or mixed.
    It needs a bit of "think out of the box" but is doable.
    More literature H E R E

    I have 5 (five) grants on my address so not aware of any limitations per house per grant, exception not same grant applied twice for same technology / upgrade.

    Good luck.


  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    AND, very important to mention here with solar evacuated tubes... maintenance,maintenance and monitoring / alerts / status updates.
    Once the water reaches a high preset temperature (mine is set at 80 ) it will stop the pump and the agent will just stagnate inisde the system.
    I've seen temperatures of over 200 degrees,for a period of time.Nothing wrong yet but keeping under this kind of stress it makes the agent weak requiring changes in few years time,shorter than the usual usage.

    My controller and data logger and VBus back end send me alerts if temperatures reaches certain thresholds,low or high.

    Normal, you will dump that heat to a dumping device.I love to get a free big lasy bath...

    My system yesterday gave me hot water in a single day for the next 2 (two)days.... now, if i can use that scalding water as a big storage buffer somehow somewhere, it will be handy...


    480337.jpg


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    rolion wrote: »
    I've seen temperatures of over 200 degrees,for a period of time.Nothing wrong yet but keeping under this kind of stress it makes the agent weak requiring changes in few years time,shorter than the usual usage.


    Normal, you will dump that heat to a dumping device.

    Again, in a more sophisticated system like the Kingspan Solartherm, the tubes vent so there is no excess heat (over 95C iirc) so no extra degradation on the coolant needing replacing more often. Also no need for a heat dump

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



  • Closed Accounts Posts: 3,364 ✭✭✭ rolion


    unkel wrote: »
    Again, in a more sophisticated system like the Kingspan Solartherm, the tubes vent so there is no excess heat (over 95C iirc) so no extra degradation on the coolant needing replacing more often. Also no need for a heat dump

    May i ask to send me some literature / documentation about the system, please.


  • Moderators, Category Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 58,884 CMod ✭✭✭✭ unkel


    rolion wrote: »
    May i ask to send me some literature / documentation about the system, please.

    Description of how Kingspan Thermomax system works and link to full datasheet here:

    linky

    "Wind is Ireland's oil" - An Taoiseach, 25/05/2022



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  • Registered Users Posts: 2,544 ✭✭✭ MicktheMan


    OP, how much oil do you currently use per year to heat your house and hot water?
    Reason for asking is that your "few euro put aside" may be better invested on reducing your overall heat loss.


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