How To Calculate | Heat Loss Central Heating | NGCFE

[@davidsanders904]

I'm not a heating engineer, but that was a great insight into how they should calculate heat loss. I have started the process of getting an Air Source Heat Pump and it will stand me in good stead when talking to my heating engineer when he starts the design process I'm sure. I am also beginning to understand the importance of making the right choice in terms of the size heat pump too. In this case size does matter, but big is not necessarily better! Lol

[@pipedreamtv9697]

For your Floor area shouldn't you be using a mean ground reference temp of +6.5°c as per Cibse book giving you a DT of 14.5°c?? And secondly where the heck do you get u valves for internal doors, nobody I contacted could supply a u value for them, generally we would just want an approx u value for solid and hollow doors as this would cover most cases as the temperature / heat loss/ gain on the other side would only be marginal. You used a u value of 1 what type of door was that?? Thanks

[@AllenHart999]

Thank You

[@Bikebros27]

Where do u get the info for the air changes in the room u mentioned the bathroom has 3 air changes an hour. Where did u get this from. Many thanks.

[@jamescowling5019]

Hi Allen, great video as usual, I have purchased the new book, just a few questions to clear up please, so as from June 2022 we need to install new boilers to run at a maximum of 55*C so flow temperature 55*C return temperature 35*C so radiator temperature 45*C (I can’t find any data sheets at the moment for radiators running at these temperatures) also need to install an immersion timer to come on once a week to achieve Pasteurisation, is this correct or am I over thinking this new legislation? Thank you

[@kylejames5121]

there are correction factors for different delta ts online

[@footballfanatics49]

Thank you so much , really liked it, It would be appreciated if you do a series where you describe the next step in heating calculation , like radiator sizing, insulation improvement,then heat pump design.

[@plumbertime]

What temperature does a boiler give out it’s said kw Should we be considering that?

[@aleksandarstojanovski1005]

I understand the calculations, but I always struggle to find the U values for some specific material. Can you suggest me where can I find databse with U vlaues?

[@dave3041]

Fair play for taking the time do that presentation. Really well explained too. Well done 👏

[@AllenHart999]

Thank You

[@rossco5301]

Been watching your videos for quiet some time now helped with so much I’m currently at college but the college can’t put an extension on for me to finish my portfolio so do u know how much you would be talking for me to sit a gas course my self roughly am from Lanarkshire Scotland

[@AllenHart999]

£4k maybe

[@Allegedly2right]

Nice video but most old houses have a fireplace surprise surprise forgot about that haven’t we,not having ago it’s just 50% of houses have a open fireplace and the bathroom will have a extractor above the shower which is just a open hole.So can you show some info on thatI am a nightmare.so what heat pump would you put in there I have had EPC done twice shot them down because I haven’t read that book.How to Size? Missed that bit

[@handle1196]

Are the air changes based on natural ventilation or mvhr (mechanical ventilation heat recovery) for airtight houses? Just wondering how to factor these in when using mvhr. I will receive calculations for my air changes per hour from the design company.

[@AllenHart999]

Natural ventilation

[@edmetcalfe8974]

I’m probably missing something but can’t see the link to the heating design book. Could you post it please Allen?

[@AllenHart999]

www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IhQ78QAF

[@joncoke8208]

Great video allan art! Erm can you do a video of pipe sizing, radiator sizing and also range rating the boiler, as if the house only needs 4 kw of heat output then how do we set the kw rating of the boiler, also smart controls like weather comps etc please keep up the good work

[@mickbmx]

if ive got a room at 21c and an outside temp of 5c and the inside drops by 2c in an hour how many kw's have i lost?

[@vkman34]

People often leave the internal doors open - what's the U-value of an open door? I would ignore internal heat transfer between rooms: it's too unpredictable.

[@philfarrell5928]

Where can you get that table with U values gents the ones used on video

[@efrygasservices6169]

Ace video and very well timed with the new rules coming into force soon. Well done fellas 👍

[@AllenHart999]

Hope you are well buddy. Thanks.

[@simonkay2273]

Great video as all ways. Can't see the link for the book in the video

[@AllenHart999]

www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IhQ78QAF

[@simonkay2273]

Thanks Alan

[@paulgerrard2529]

Shouldn’t the resistance of the materials be calculated first ?

[@vlodski73]

Thank You for your podcast! Much appreciated!

[@fredjennings9268]

Thanks for all your time . Great insight for everyone. 👏👏👍

[@AllenHart999]

www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IhQ78QAF

[@jockster5525]

Quality upload mate .. been looking forward to seeing this .many thanks for your efforts ❤️

[@AllenHart999]

Let us know if you would like any other videos. Thanks.

[@rayl9969]

Hi Alan graef video as usual what is the books title please 👊

[@AllenHart999]

www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IhQ78QAF

[@rayl9969]

Thank you 👊

[@stevenlightfoot121]

@alanhart . Hi Alan Do you know of any companies wich would do this for you ? I have 5 big new builds to price up and would be interested in a heat loss / system designed thanks mate 👍

[@MrKlawUK]

interesting. But a lot of assumptions made and with maths, small differences could add up. I wonder how many rooms/houses fit to these assumptions - a lot of us will have older/leaky windows, perhaps slumped cavity wall insulation etc. and air changes feels like guesswork (well an ideal I suppose). but its good data - if I was looking to do this I’d probably review afterwards and use that to experiment with fabric / air improvements to see how that reduces heatloss - before putting in any changes to the heating

[@brendanfisher2528]

Great video... its alot to learn.. I'm looking into doing my ASHP course

[@Swwils]

Well done for having a crack at it.

[@AllenHart999]

www.cibse.org/knowledge/knowledge-items/detail?id=a0q3Y00000IhQ78QAF

[@SD-Plumbing-Heating]

Are these heat loss calcs for installing ASHP? As this seems very drawn out for replacing a combi.

[@davewellsheatingengineer]

Hi, all the same , heat loss is heat loss.. so even fitting a combi that will almost always be oversized for heating, it is important to know actual heating requirement to enable accurate range rating of the appliance and its minimum flow temp.

[@dorsetengineering]

Changes to part L this year will (finally) force installers to properly size up stuff for lower flow temps. You can’t do that till you’ve done a heatloss calc, room by room. Then you can size emitters properly.

[@SD-Plumbing-Heating]

@@dorsetengineering If customers are after a replacement boiler, they won't have extra money to pay for larger rads plus install costs. People's money is getting lower and lower, without having to to spend on extra rads(cost of living).

[@SD-Plumbing-Heating]

@@davewellsheatingengineer I think the government should pay for installers to do a course to properly carry out heat loss surveys, which won't be a quick job in a house with 15/20 rads or rooms.

[@davewellsheatingengineer]

@@SD-Plumbing-Heating did you not do heat loss calcs at college? There are some good apps out there, probably takes me an extra 20 mins .. its not too bad, I find I only have to replace a rad or two to get system running at 50c so not a big extra cost to client

[@h2xengineering]

Great watch, thank you for sharing!

[@AllenHart999]

Thanks for watching!

[@muhammadgreen9711]

Great vid love watching and learning the calculations side of things gives you more knowledge in your field. Would like to see more for boiler sizing, expansion vessel sizing, pump sizing and hot water cylinder sizing 👍 trying to keep you busy Allen lol 😂

[@AllenHart999]

Thank You

[@Montassercharni]

Hi Allen It’s a great session well and simply explained,it’ll be perfect if you can please do videos with the whole installation sizing (pipes, pump ,boiler ,expansion vessel sizing )

[@serhiydryzhenko5860]

Is anyone know what book is Alen holding?

[@eamonhouston3265]

How do you work out mean ground temperatures for solid concrete floors. CIBSE design does not explain very clearly.

[@MrFlyby34]

Brilliant explanation thanks!

[@heatpump8566]

Great vid

[@vidleon]

Installing larger radiators means more water for the boiler to hear, yes, at a lower temperature, but effectively how much energy is being saved. Lower temperature v higher volume of water.

[@AllenHart999]

i get what you are saving.

[@rodgerq]

Great again!!

[@ChimellaTheChimneyUmbrella]

If you have a chimney, get yourself a Chimella. You will save £££s on your energy bills