marshian

Are you trying to stay inside the BUS grant so effectively a “free to you” change to ASHP? if no rad/cyl changes then where is the £7500 going?

Thanks Probably a good time to provide a review In summary - I found the "Open Heat Loss" tool easy to use (The dt element between rooms/external areas probably needs a bit more notation to explain what it's trying to achieve from a "non heating engineer" perspective - clearly you had an excellent understanding of it and could fix my schoolboy errors) I completed the whole house heat loss over two evenings - maybe 2 hrs each day I did however have 1. All the dimensions of floors, walls, windows and doors in a handy table 2. All the U values for the fabric elements of the house noted down Both the above from a previous heat loss exercise which made data entry quite quick and easy It works on phone (if a little scrolly) Android tablet and PC The various report pdfs are great as a summary snapshot I need to go back to my pipe work section and revisit that as I took a punt on lengths I effectively have two circuits linked together just after the pump If I was to suggest anything it would be - from a room to dT perspective it would be good to link ground floor to upstairs (In my mind I have a "room above" or "room below" selection process) how feasible that would be I don't know

OK that makes sense - I considered removing all the doors from the landing the whole landing, hallway stairwell area is also a bit tricky I broke it into chunks to make it easy for me as they are all linked but only one radiator (albeit a big one) is in the lower hallway (so the tool says it's oversized) however if I add all the reqts together it's in line with the other rooms It used to be a 550 by 800 T11 - it's now a 500 x 1400 T22 Makes perfect sense - before I insulated between the joists of the ground floor with 75mm PIR you could feel a draft in most rooms when the wind got up - now it can be a bloody good gale outside and there is no drafts at all........ I know I've got the house reasonably well sealed hence the installation of a PIV unit to manage humidity and ACH's (But it's not MVHR )

Last point - pretty sure it's ventilation losses that are driving the higher calculated heat loss Fabric is now 4144 W Ventilation is 3090 W Anyway to reduce that ventilation factor? I guess I see a blower test in my future

OK checked out the changes - made a couple of tweaks now I understand the logic More stupid questions 6 rooms upstairs all have doors then I treated the landing as a room and put 6 doors in there.......... Ceiling for all upstairs rooms is plasterboard & then 300mm Insulation and over boarded - temp in the loft is always 2 to 3 deg above OAT should I be lowering the delta from room to ceiling Same with the temp below the suspended ground floor it's always higher than OAT

Bloody amazing Simon - thank you I'll go in and check out where you've made the changes

Amusingly for me anyway the total actual Rad output is spot on for my heat loss I know I've cocked up somewhere just can't see where 🙂

Sent you a PM

Rad Evaluation at my Target Flow Temps

heat rises easier than it falls??

So now I need to understand why the result (if I am reading it right) at 12 kWh is 3 times my current heat loss 🙂 Current heat loss is just under 4.0 kWh at -2.5 Deg C So I've definately made an error somewhere

U Values used

OK Finished Two Warnings I think I understand both are due to the internal nature of the Hall and Landing being centre of house so no external wall ticked

One question - might seem a bit stupid In a two storey house Ground Floor gets the downstairs floor does it get the ceiling as well or does the upstairs floor get the ground floor ceiling as it's floor and the ceiling between it and the roof structure? At the moment ground floor has ground floor and ceiling, first floor has floor and ceiling - concerned that this may be double counting?

Ref phone comment - yes it works but it's not optimised for the small view (may not help my phone is set for larger text view) - it's possible just not as easy as PC or Tablet

Windows Just about to try it on android tablet (but I let the battery get flat so it needs a charge first)

Glad I checked - will have to get my head around that.

66.2 m2 floor area (this includes the internal brick walls) 32.6 m External Walls So 0.67?

Using firefox

One small bug I have found - when entering Rads everything works fine till you get to the l/m - it will only let you enter whole numbers (not number to two dec places) but once a whole number is entered you can increase or decrease it in steps of 0.01 - easily worked round but a little slow to get to the right value

Perfect sense - I'd like to sense check the result with you if I may?

Next Question Flooring area P/A specifically House is a stupid T shape (I have mentioned this in threads before) it was L shaped originally but we added an extension to the rear of the house in 2006 Do I treat the floor area as two rectangles or work out the floor area and enter it as a "square" size that meets the area?

Ahh good to know - I tried various methods and none seemed to work (As a registered user) OK I get you but for me heat emitters are all about surface area (especially at low flow temps), flow rate and volume of water Take my 1800 x 578 vertical it has a volume of water of 10 Litres 10 litres divided by 0.578m width = 17.3 l/m 10 litres divided by 1.8 height = 5.5 l/m Compare that to my K33 1400 x 700 with a capacity of 14 Litres 14 litres divided by 1.4 = 10 l/m 14 litres divided by 0.7 = 20 l/m OK now I bloody get it - ignore me I'm stupid - it's basically looking at how much volume you have per m as a factor and you need to always use the width................... You've clearly put a lot of effort into it - it seems quite polished already - I do like the "not to current regs" pointers (I've got an 80's house - extended in naughties so stand no chance of being to current regs but I've improved it where I can

email sent - to be honest adding rads has been my biggest issue - doesn't seem to want to save them! I know all my rads are pretty much spot on size wise for flow temps I'm using and house heat loss - I've made all the mistakes and learnt from it - I'll use two column So even with a vertical rad that is 1800 mm high you divide the volume by the width? I get that for a panel rad it would work that way but thanks - good learning point Ahh this makes sense now - thank you I'll do that next time I'm back at it That was my approach after I screwed up the first room and didn't know which external wall I was adding a window too As I said - I like it and I haven't broke it yet which is what I'm normally paid to do

OK few questions Rads Adding radiators to the database - is that to a central database so others can look up or just for the project in question What would I select as type for a 1800 x 578 double flat tube vertical rad I know the kW rating at T50 I know the volume of the rad (because I measured it on a drain down - call me sad if you like) but how would I calculate the litres/metre U-value (W/m²·K) I know the U-value for my external walls Brick 102mm Mineral wool in cavity 50 mm 100mm std aerated block 13mm plaster is 0.45 (well that's the closest approximation to what I have) So on external walls I should select a U Value of 0.45 but I can't seem to change it from the default 0.10 am I muddling my units?