Home  5  Books  5  GBEzine  5  News  5  HelpDesk  5  Register  5  GreenBuilding.co.uk
Not signed in (Sign In)

Categories



Green Building Bible, Fourth Edition
Green Building Bible, fourth edition (both books)
These two books are the perfect starting place to help you get to grips with one of the most vitally important aspects of our society - our homes and living environment.

PLEASE NOTE: A download link for Volume 1 will be sent to you by email and Volume 2 will be sent to you by post as a book.

Buy individually or both books together. Delivery is free!


powered by Surfing Waves




Vanilla 1.0.3 is a product of Lussumo. More Information: Documentation, Community Support.

Welcome to new Forum Visitors
Join the forum now and benefit from discussions with thousands of other green building fans and discounts on Green Building Press publications: Apply now.




    • CommentAuthordnfh
    • CommentTimeJan 10th 2008
     
    I like UFH (warmish feet, cool head, no radiators to damage antique furniture etc), but am getting very confused on how to power it. I would be very grateful for the wisdom of the experts!

    c. 6kW heating needed, + c. 2kW HW. Old house so may be too leaky for HRV to be worthwhile (abut to be tested). Insulated about as well as possible.
    UFH Heating:
    Initial plan was ASHP 'cos of COP 3 etc, but as gas is 4x cheaper a new boiler might be better? There used to be gas fridges (at least for caravans etc). Would a gas ASHP - if it exists - be the answer?
    If we could provide the electricity ourselves then ASHP would be great. No hydro, wind dubious (site considerations and Conservation area) and PV limited and V. expensive (but may be useful in 5 yrs?).
    microCHP. Apparently for a small increase in gas will proivde effectively free electricity - ? 2kW
    wood pellet boiler? Don't know much about them.

    HW: solar probably, but top-up with what?
    Gas boiler is easy.
    Could use another ASHP with lower COP for 50oC HW, but still electricity problem.

    Any thoughts?
    • CommentAuthortony
    • CommentTimeJan 11th 2008
     
    GSHP is best then ASHP gas is a long way down the list If you want to use solar then how about an inter-seasonal thermal store?

    It is unlikely that you would be able to generate enough pv electricity to power heating unless you spend on insulation and eliminate the need for a heating system

    What is your floor? Are we talking new build?

    Solar heat for hot water is the way to go and to extend this to a mega huge thermal store is my favorite option.




    ?
    • CommentAuthordnfh
    • CommentTimeJan 11th 2008
     
    GSHP not possible (no space, and Conservation area won't allow borehole). ASHP I have seen several working over > 1 yr with good effect, but all are electric. Is there a gas ASHP?

    I have heard of thermal stores, but know little. I assumed they could only buffer for a few days rather than over the whole winter? Any articles to bring me up to speed? What size are you thinking of?

    Old house (1770) stone walls, solid ground floor (will have 75mm insulation) timber 1st floor.

    With solar I have seen two studies comparing flat plate with tubes. One said flat plate was BETTER (apparently normalised power to SA but took the total SA of all cylinders rather than the exposed area); second said not much in it. Yet others say tubes are much better. Any comments?
    • CommentAuthorCWatters
    • CommentTimeJan 11th 2008
     
    You have an old house and yet it only needs 6KW? That's not bad.

    Is gas really only 1/4 the price of electricity these days? I wonder if it almost makes sense to run a gas powered generator and make your own? I know gas motor aren't very efficient but with four times the price to play with you only need be 25% efficient overall. Perhaps a small Honda petrol generator and gas conversion kit? Feed the electricity produced to an ASHP (You could even feed the exgaust through the ASHP to improve efficiency)....na it can't make sense can it?
    • CommentAuthorGreen man
    • CommentTimeJan 11th 2008
     
    Wood and solar is a good option with a thermal store! We have a log gasification boiler 25kw with a 1500 ltr thermal store. We have added 6 x 30 tube evacuated tube panels to the system (about 20 sq.m) This gives us about 15kw/hrs peak towards the hot water and underfloor heating. We also have a condensing boiler working alongside the log gasification boiler both heating the store direct. The underfloor heating is 150 sq.m of which draws from the thermal store by a special mixing pumpstation. We also have a programmer which automatically switches between the log boiler and the condensing boiler. This works by when the temperature rises at the log boiler when you heat the logs, the temp sensor then registers at the programmer that the boiler is on and shuts off the condensing boiler. It then diverts the water heated by wood to the store by a special motorised valve.

    For hot water we have an external pumpstation which when the hot tap is opened a flow switch draws the heat out of the store to the station and transfers the heat giving us 42 l/m.

    It didnt work out expensive wefound a very good local supplier of the goods who also designed the system for the plumber
    Try this link www.ph-renewables.co.uk they worked out very reasonable for the goods
    • CommentAuthortony
    • CommentTimeJan 13th 2008
     
    Cannot see why conservation area will not allow a borehole?? Are you sure it is all underground.
Add your comments

    Username Password
  • Format comments as
 
   
The Ecobuilding Buzz
Site Map    |   Home    |   View Cart    |   Pressroom   |   Business   |   Links   
Logout    

© Green Building Press