Yes still asking for it
Edit: I Just put in 00000 as gsr number and has been approved
System advice
- Thread starter b21playa
- Start date
Edit: I Just put in 00000 as gsr number and has been approved
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I spoke to the team just before this evenings webinar so they can't have done it. I'll see about that number, that's a glitch if it works elsewhere.
Yes, I asked about this and apparently you'd tried on the earlier webinar without success and then again more recently for the next one (you use a funny or unusual name) but in the meantime I'd mentioned that someone couldn't sign on so they registered it.
Yes I stupidly used autocomplete which used random details for another web form I had used.
Thanks for getting back to me, much appreciated
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I had to make many assumptions of course, they're listed below.
Postcode I chose was Sutton Coalfield.
-3.7 external design temperature
230mm solid walls
Uninsulated timber ground floor
Uninsulated timber intermediate floors
Standard PVC/wood double glazing throughout
200mm insulation in loft spaces
Shiplap cladding and insulation for external walls in loft conversion
2.6 ceiling heights first two floors 2.4 second floor.
I was surprised at the heat loss of 28.95kW space heating although that's to heat the property in an hour, once the building is warm it becomes its own thermal store.
I laughed at the pipe layouts in the drawings, they'd never be practical, I drew them again missing fireplaces and running with and across roof joists. Pump I'll do tomorrow
Postcode I chose was Sutton Coalfield.
-3.7 external design temperature
230mm solid walls
Uninsulated timber ground floor
Uninsulated timber intermediate floors
Standard PVC/wood double glazing throughout
200mm insulation in loft spaces
Shiplap cladding and insulation for external walls in loft conversion
2.6 ceiling heights first two floors 2.4 second floor.
I was surprised at the heat loss of 28.95kW space heating although that's to heat the property in an hour, once the building is warm it becomes its own thermal store.
I laughed at the pipe layouts in the drawings, they'd never be practical, I drew them again missing fireplaces and running with and across roof joists. Pump I'll do tomorrow
yes pipe layouts were a bit crude, they of course would be run straight either under joists on ground floor and through joists on upper floors.
There no to little loft insulation in the house, the area isn’t really accessible, I’ve only seen it through a hole in the eaves storage and at max would be 100mm if that. Loft conversion has no insulation either! Postcode is B38 kings norton. Ceiling height 2.7m first 2 floors and 2.25mm for loft
Do the calcs include a 250L unvented tank? Wouldn’t the pump be sized in the boiler being a system type?
I really appreciated the help, thanks
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I've got a bit of a cold at the moment and noticed this morning some of the survey details I entered from the survey sheet on the app have not been transposed correctly to the report that I have access to. It may be a fuzzy me yesterday evening, it may be because I see my status at Heat Engineer has changed to a demo version for educational purposes now which may mean there have been other anomalies (I was granted free use to demo to course attendees at our centre and webinars). Heat Engineer is a charged for facility, and rightly so, it is so good.
Some of the rooms have heat requirements oversized to what I would expect so I'd be inclined to drop that figure. It would drop anyway with continual heating at comfort and setback temperatures.
Hot water I would not add as I'd suggest to a customer they use priority domestic hot water with a condensing boiler as it improves efficiency in space heating mode. Sored hot water is reheated with a fast recovery cylinder using the whole output of the boiler at high non-condensing temperatures in a short space of time then space heating resumes at low temperatures in condensing mode. Over 80% of your energy bill will be space heating, DHW is comparatively small so maximize low temperature operation.
With regard to pump. If you want to maximize efficiency in all areas one thing is to operate the system with a wide ΔT across the system and boiler. An optimal ΔT of 20°C means a fair bit of balancing and matching pump performance. Some of the boilers at high output you may be considering can have very little residual head after losses within the boiler exchanger have been overcome, even those with 7m and 7.5 metre head pumps meaning use of an additional pump.
You may be looking at 1200l/hr if you operate at ΔT 20 which will leave little head on the pump with some boilers (on our system boiler just under 3.5m head at that flow rate) and you have a large system. Unless pipe sizing is carried out to keep head loss down, which is perfectly possible, there may be problems and I don't know how the pipework is run or sizing. It would be doable on some with the boiler pump possibly not with others.
Some of the rooms have heat requirements oversized to what I would expect so I'd be inclined to drop that figure. It would drop anyway with continual heating at comfort and setback temperatures.
Hot water I would not add as I'd suggest to a customer they use priority domestic hot water with a condensing boiler as it improves efficiency in space heating mode. Sored hot water is reheated with a fast recovery cylinder using the whole output of the boiler at high non-condensing temperatures in a short space of time then space heating resumes at low temperatures in condensing mode. Over 80% of your energy bill will be space heating, DHW is comparatively small so maximize low temperature operation.
With regard to pump. If you want to maximize efficiency in all areas one thing is to operate the system with a wide ΔT across the system and boiler. An optimal ΔT of 20°C means a fair bit of balancing and matching pump performance. Some of the boilers at high output you may be considering can have very little residual head after losses within the boiler exchanger have been overcome, even those with 7m and 7.5 metre head pumps meaning use of an additional pump.
You may be looking at 1200l/hr if you operate at ΔT 20 which will leave little head on the pump with some boilers (on our system boiler just under 3.5m head at that flow rate) and you have a large system. Unless pipe sizing is carried out to keep head loss down, which is perfectly possible, there may be problems and I don't know how the pipework is run or sizing. It would be doable on some with the boiler pump possibly not with others.
Thanks for that, would I be better with a heat only boiler (like my vailllant 438) and a separate pump as I already have a newish grundfos pump and the boiler would presumably be smaller and more likely to fit in the cupboard with a tank
Pipes are going to be 22mm everywhere except for last few meters to each radiator. No two rads will be fed off a 15mm pipe.
which rooms are oversized and I’ll take a look a radiator sizes as I’ll be ordering a few for downstairs shortly
I’ve just ordered a coil of 50m 22mm to start piping up a few rooms downstairs…..not all of it is ready but can do the hall and front & back lounges
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22mm everywhere is not necessary and coils usually mean plastic which I wouldn't use (just personal predjidice).
If you pipe size to get loss less that 3.5 m it can be a boiler pump. A Vaillant for example does not have a lot of residual head in an integral pump AFAIK.
You seem to be taking on too much yourself in my opinion, I think a house that size an experienced installer would be the way to go. One who has been recommended by people you know and who has worked for them personally, not someone's nephew or neighbour.
More expensive for sure.
If you pipe size to get loss less that 3.5 m it can be a boiler pump. A Vaillant for example does not have a lot of residual head in an integral pump AFAIK.
You seem to be taking on too much yourself in my opinion, I think a house that size an experienced installer would be the way to go. One who has been recommended by people you know and who has worked for them personally, not someone's nephew or neighbour.
More expensive for sure.
I know what you mean about plastic, not really what I’ve done before, always been full copper but due to time etc I’ve decided on plastic. As I’m doing this gradually while working through the whole house, it works well.
I’m sure the current 15mm is causing issues of the house not heating up. The heating was on most of the day and even with the sun out, I still didn’t feel warm.
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Hi Vulcan. Even though some rads are over sized, can I just not turn them down? It would give give me the option to turn up if needed
if they're over sized why would you need to turn them up, what would make you need to? Couldn't help it. Oversized radiators are fine, they enable you to reduce the system water temperature yet emit the same amount of heat. This it to the advantage of a condensing boiler, the cooler they run the more efficient they become.
Haha. Turn them up if it’s still too cold.
Oversized radiators are fine, they enable you to reduce the system water temperature yet emit the same amount of heat. This it to the advantage of a condensing boiler, the cooler they run the more efficient they become.
I did read oversizing was better. I’ve ordered some rads for a few rooms which should be delivered in the next week or so and hoping this makes a difference, although still not too sure on boiler sizing or whether to go system/heat only
Just a small update....this weekend I removed 6 old radiators and replaced them with new along with new pipework. The old was all in 1/2" copper under the floorboards. Now replaced with 22/15 and the rooms warm up quicker and the boiler seems to condense rather than just cycle. Just need to figure out a plan to do upstairs now
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