heat loss for new builds

[sheff paul]

Pricing for some new builds,anyone know some easy on line heat loss calcs ,the ones I usually use are more geared towards older homes ,not heavily insulated new builds.

 

[LPC]

Judging by some of the new builds i've been in, a 600 x 600 single by the front door should be more than enough!

 

[Whyme]

Just use a normal one or mears..The constructions been around for ever and a day. Find out what insulations been put in ie king span, fibreglass etc etc. the old is the same as the new. just takes a bit of looking at in person or architects spec..I dont think theres a new build specific calc out there at the moment.

 

[lame plumber]

I got a mears off ebay based on nice insulated new builds, have yet to use it!

 

[AWheating]

Ask the builder the u values and do proper calculations. Or if it's just for quote just use online software which will prob be slightly high and if you win the work then do proper calculations.

 

[oz-plumber]

This is a real point of contention with me.

I have used the Mears Calculators for many years for heatloads, with some tried and tested adjustments for heatloads in Melbourne.

I purchased last year a new computer program for heatloads for Australian conditions.

well, after spending all the time in inserting all the required information into the program the heatload was larger than the Mears Calculator.

Mind boggling - due to our temperature is @ 4C in winter and I think the Mears calculator is based on -1C.

I would just use something you feel comfortable and confident with.

What the worst that can happen - you slightly oversize a heating system.

 

[Ermintrude]

Just use a normal one or mears..The constructions been around for ever and a day. Find out what insulations been put in ie king span, fibreglass etc etc. the old is the same as the new. just takes a bit of looking at in person or architects spec..I dont think theres a new build specific calc out there at the moment.

Just build a spread sheet. Energy losses not that hard to calculate. Every element has an thermal conductivity.

 

[chris watkins]

This is a real point of contention with me.

I have used the Mears Calculators for many years for heatloads, with some tried and tested adjustments for heatloads in Melbourne.

I purchased last year a new computer program for heatloads for Australian conditions.

well, after spending all the time in inserting all the required information into the program the heatload was larger than the Mears Calculator.

Mind boggling - due to our temperature is @ 4C in winter and I think the Mears calculator is based on -1C.

I would just use something you feel comfortable and confident with.

What the worst that can happen - you slightly oversize a heating system.

Or you loose the work cos someone tenders lower, as their rads are smaller but still heat the building.

 

[chris watkins]

With the ones like Stars or Myson / Heatline you can input your own U-values even if the actual construction is not given. These U-value can be obtained from Part L which states the minimum that the Architect / builder can use for each of the elements (walls, floors, roof, windows etc).

I use the Myson one (even though I hardly ever use Myson rads, I just take the require figure to select other makes which are delta T 50deg C.

 

[sheff paul]

With the ones like Stars or Myson / Heatline you can input your own U-values even if the actual construction is not given. These U-value can be obtained from Part L which states the minimum that the Architect / builder can use for each of the elements (walls, floors, roof, windows etc).

I use the Myson one (even though I hardly ever use Myson rads, I just take the require figure to select other makes which are delta T 50deg C.

can you download the myson one Chris,or do you have to buy it

 

[Ermintrude]

Or you loose the work cos someone tenders lower, as their rads are smaller but still heat the building.

Must be doing something wrong, the calcs can't be more than 10% out and 10% output diff on a rad is pennies, even if your heating a huge space with rads - never do can't see being more than a £30 a plot. If your loosing on rad sizes must be awful working that tight on jobs. We loose jobs on a few occasions but when it's that tight why bother?

 

[chris watkins]

can you download the myson one Chris,or do you have to buy it

http://www.myson.co.uk/static_files/my/media/downloads/24372_Eco_BrochureSpreads.pdf
Page 12 it says phone them & they will send one out, you use to be able to request it on line but not download.
If the need to down load try Ideal Stars this new one is good.
Stars App | Heat loss calculator for any room

 

[Pipes Plumbing]

I have a spreadsheet that I built for when it needs to be accurate (calculates Fabric & Ventilation heat loads seperately), and I use STARS when I need a quick and dirty version for a ballpark estimate...

The spreadsheet wins out when it comes to accuracy, so long as I have done the survey and measurements properly... Any tool can only be as good as the information that is put into it.
The accuracy really helps when sizing Biomass / Solid fuel systems and forecasting fuel usage etc.