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Gas calculators built for the meter in the cellar
Gas rate, installation volume, ventilation, pipe sizing and heat loss. Work it out on the phone with no signal, by voice if your hands are full, and I put the result on the certificate or save it on the job.
No card needed. Unlimited for 14 days. Cancel any time.
Current standards
Installation volume to IGEM/UP/1B Edition 4, ventilation to BS 5440-2:2023.
No signal needed
Every calculator works in the cellar and the result goes on the job back in range.
Onto the certificate
Results drop straight onto the certificate or save against the job.
Gas rate at the meter, hands-free
Two meter readings and the time, or use the built-in stopwatch. Metric or imperial meters, natural gas or LPG. I give you the gas rate and the gross and net heat input, and it goes onto the certificate without copying figures across. Gas rate, installation volume, ventilation and single-run pipe sizing all work by voice, so you can do the sum with a torch in one hand. In a cellar with no bars, save it to the job anyway and it lands there by itself once you are back in range.
- Metric or imperial, natural gas or LPG
- Gas rate plus gross and net heat input
- By voice, and with no signal
Installation volume to Edition 4
IGEM/UP/1B Edition 4 is mandatory from 1 October 2026, and the installation volume calculator is built to it. You get the installation volume, the purge volume and the permissible pressure drop, and one tap puts them on the Gas Testing & Purging record with the working kept, so anyone checking later can see how you got there.
- Built to IGEM/UP/1B Edition 4
- IV, purge volume and permissible pressure drop
- Onto the Gas Testing & Purging record, working kept
Ventilation, pipe sizing and heat loss, honest about their limits
Ventilation is to BS 5440-2:2023 for open-flued and room-sealed appliances in a room. It doesn’t do flueless appliances, decorative fires or compartments yet, and says so rather than guessing. Pipe sizing is to BS 6891 for copper on natural gas, including branched runs where the drop has to be shared, and it refuses steel and LPG rather than use the wrong table. Heat loss goes room by room for sizing boilers and radiators, with every wall, window and floor given its own temperature difference. It is not an MCS heat pump design, and the first screen says so.
- Ventilation to BS 5440-2:2023
- Pipe sizing to BS 6891, branched runs included
- Room-by-room heat loss for boilers and radiators
Do the sum where the meter is.
Five calculators, no signal needed, straight onto the certificate.
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Get the sums done on site
Try everything free for 14 days. No card needed, cancel any time. I will be set up and helping from day one.
£29/month for a solo owner, £39 per user per month for teams of 2 or more. Subbies are free. Cancel any time.
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