Es Tresidder
@estresidder.bsky.social
High-energy mountain sports, low-energy building design. Runner, climber, ski-mountaineer, building physicist & Passivhaus designer. EV driver.
Currently finishing up my own EnerPHit house project.
Currently finishing up my own EnerPHit house project.
That’s encouraging, thanks Robert. Heated seats should also reduce need for cabin heating, although on our Leaf we often need heating to keep windscreen clear.
April 21, 2025 at 12:56 PM
That’s encouraging, thanks Robert. Heated seats should also reduce need for cabin heating, although on our Leaf we often need heating to keep windscreen clear.
Hi Rob. Sorry for slow reply, not been on socials much.
Don’t know if any examples off the top of my head. Happy to help if I can, drop me an email.
Don’t know if any examples off the top of my head. Happy to help if I can, drop me an email.
April 21, 2025 at 11:49 AM
Hi Rob. Sorry for slow reply, not been on socials much.
Don’t know if any examples off the top of my head. Happy to help if I can, drop me an email.
Don’t know if any examples off the top of my head. Happy to help if I can, drop me an email.
Soz not been on Bluesky much.
Found a small amount of asbestos in one place. Didn’t test concrete.
Found a small amount of asbestos in one place. Didn’t test concrete.
April 21, 2025 at 11:41 AM
Soz not been on Bluesky much.
Found a small amount of asbestos in one place. Didn’t test concrete.
Found a small amount of asbestos in one place. Didn’t test concrete.
With PV I expect our electricity bills for everything, including charging an EV, to be ~zero. 💪
*possibly won’t cover the standing charge.
*possibly won’t cover the standing charge.
March 2, 2025 at 7:15 PM
With PV I expect our electricity bills for everything, including charging an EV, to be ~zero. 💪
*possibly won’t cover the standing charge.
*possibly won’t cover the standing charge.
This includes an increase in average internal temps (from 17° to 20°). Couple these sort of demand reductions with well designed and commissioned heat pumps and you get super low energy bills; our heating and hot water comes in at less than £170 a year before factoring in PV 🌞
March 2, 2025 at 7:14 PM
This includes an increase in average internal temps (from 17° to 20°). Couple these sort of demand reductions with well designed and commissioned heat pumps and you get super low energy bills; our heating and hot water comes in at less than £170 a year before factoring in PV 🌞
@aecb.bsky.social retrofit standard and #Passivhaus EnerPHit typically deliver much higher reductions in heat demand than that. I’m working on half a dozen timber-frame deep retrofit projects, and an 80% reduction in annual heat demand is typical.
March 2, 2025 at 7:11 PM
@aecb.bsky.social retrofit standard and #Passivhaus EnerPHit typically deliver much higher reductions in heat demand than that. I’m working on half a dozen timber-frame deep retrofit projects, and an 80% reduction in annual heat demand is typical.
Didn't really feel this episode was pushing back against MVHR, just highlighting that it needed to be done well. Did you?
January 23, 2025 at 2:50 PM
Didn't really feel this episode was pushing back against MVHR, just highlighting that it needed to be done well. Did you?
I’m not sure what the deal is with condensate on those single room units, I’ve never had one on a project, see what the manual says.
January 23, 2025 at 1:35 PM
I’m not sure what the deal is with condensate on those single room units, I’ve never had one on a project, see what the manual says.
- Clean filters (change every 6 months or more often if very polluted area)
- cross-talk attenuators if using branched ducting rather than radial.
- cross-talk attenuators if using branched ducting rather than radial.
January 23, 2025 at 8:44 AM
- Clean filters (change every 6 months or more often if very polluted area)
- cross-talk attenuators if using branched ducting rather than radial.
- cross-talk attenuators if using branched ducting rather than radial.
- Quiet units, mounted in a room where the noise won’t matter, ideally on an external wall (see bit about duct lengths).
-silencers between unit and rooms (for both supply and extract)
- appropriate ventilation rates
- high quality ducting sized to allow low air speeds in ducts and as direct as poss
-silencers between unit and rooms (for both supply and extract)
- appropriate ventilation rates
- high quality ducting sized to allow low air speeds in ducts and as direct as poss
January 23, 2025 at 8:43 AM
- Quiet units, mounted in a room where the noise won’t matter, ideally on an external wall (see bit about duct lengths).
-silencers between unit and rooms (for both supply and extract)
- appropriate ventilation rates
- high quality ducting sized to allow low air speeds in ducts and as direct as poss
-silencers between unit and rooms (for both supply and extract)
- appropriate ventilation rates
- high quality ducting sized to allow low air speeds in ducts and as direct as poss
Some other things I’ve seen and heard of being done wrong, thankfully none of these on my projects:
- looping excess ducting in the loft to reduce noise transfer to rooms
- failing to put a downslope on pipe from condensate drain, causing unit to flood (bearings needed replacing)
- looping excess ducting in the loft to reduce noise transfer to rooms
- failing to put a downslope on pipe from condensate drain, causing unit to flood (bearings needed replacing)
January 23, 2025 at 8:05 AM
Some other things I’ve seen and heard of being done wrong, thankfully none of these on my projects:
- looping excess ducting in the loft to reduce noise transfer to rooms
- failing to put a downslope on pipe from condensate drain, causing unit to flood (bearings needed replacing)
- looping excess ducting in the loft to reduce noise transfer to rooms
- failing to put a downslope on pipe from condensate drain, causing unit to flood (bearings needed replacing)
I’d always recommend getting a Passivhaus certified unit (quieter, more efficient fans, realistic efficiency %s) and getting it designed, installed and commissioned to Passivhaus requirements, even it’s a 🏡 that is going nowhere near PH standard in other areas. Quality assurance v important here.
January 23, 2025 at 8:01 AM
I’d always recommend getting a Passivhaus certified unit (quieter, more efficient fans, realistic efficiency %s) and getting it designed, installed and commissioned to Passivhaus requirements, even it’s a 🏡 that is going nowhere near PH standard in other areas. Quality assurance v important here.
Even if the ducts are super short they still need to be well insulated (I’ve seen them long *and* uninsulated), otherwise they are a risk for condensation and heat loss.
January 23, 2025 at 7:57 AM
Even if the ducts are super short they still need to be well insulated (I’ve seen them long *and* uninsulated), otherwise they are a risk for condensation and heat loss.
Even with the best (43mm EPS) pre-insulated ducts on the market each additional metre added to both ducts reduces the total system efficiency by ~1.3%. If your unit is in the middle of your house, 5m from an external wall, then suddenly your 90% efficient unit is only 83% efficient.
January 23, 2025 at 7:56 AM
Even with the best (43mm EPS) pre-insulated ducts on the market each additional metre added to both ducts reduces the total system efficiency by ~1.3%. If your unit is in the middle of your house, 5m from an external wall, then suddenly your 90% efficient unit is only 83% efficient.
One thing not mentioned in this podcast but that I’ve seen done loads, is the length of ducts between the MVHR unit and the thermal envelope. If the unit is inside both the fresh air and the exhaust air ducts are cold, and heat losses from the building to them are significant.
January 23, 2025 at 7:53 AM
One thing not mentioned in this podcast but that I’ve seen done loads, is the length of ducts between the MVHR unit and the thermal envelope. If the unit is inside both the fresh air and the exhaust air ducts are cold, and heat losses from the building to them are significant.
There’s loads of evidence that shows the conventional way of ventilating homes (trickle vents, extract fans and opening windows) leads to poor air quality, poor comfort and high energy use. Done well, MVHR will radically improve all of these, but done badly it can be a disaster.
January 23, 2025 at 7:48 AM
There’s loads of evidence that shows the conventional way of ventilating homes (trickle vents, extract fans and opening windows) leads to poor air quality, poor comfort and high energy use. Done well, MVHR will radically improve all of these, but done badly it can be a disaster.
Thanks. Mistake was I had ‘the’ at the start of the address. Have resent now.
Cheers, Es
Cheers, Es
January 16, 2025 at 11:16 AM
Thanks. Mistake was I had ‘the’ at the start of the address. Have resent now.
Cheers, Es
Cheers, Es
Share your concern for the horizontal ones (suspect they need regular cleaning). Vertical ones are just a vertical pipe within a pipe, so shouldn’t be any more likely to block than a normal down pipe.
January 15, 2025 at 3:43 PM
Share your concern for the horizontal ones (suspect they need regular cleaning). Vertical ones are just a vertical pipe within a pipe, so shouldn’t be any more likely to block than a normal down pipe.
Here’s the PHPP calc for mine. 69% efficient unit ends up as 56% efficient for 5min shower.
Also worth factoring into the payback calc:
- does it allow you to choose a smaller tank. It did for me, and that saved £200
- might allow you to do more/all of your water heating during cheap ⚡️.
Also worth factoring into the payback calc:
- does it allow you to choose a smaller tank. It did for me, and that saved £200
- might allow you to do more/all of your water heating during cheap ⚡️.
January 15, 2025 at 3:16 PM
Here’s the PHPP calc for mine. 69% efficient unit ends up as 56% efficient for 5min shower.
Also worth factoring into the payback calc:
- does it allow you to choose a smaller tank. It did for me, and that saved £200
- might allow you to do more/all of your water heating during cheap ⚡️.
Also worth factoring into the payback calc:
- does it allow you to choose a smaller tank. It did for me, and that saved £200
- might allow you to do more/all of your water heating during cheap ⚡️.
There’s a bit more to it than just the HR efficiency, also depends on length of drain pipes between shower and HX, and whether connected to cold side of shower and cold feed to tank or just one or the other, so system efficiency ends up less than heat exchanger efficiency.
January 15, 2025 at 3:11 PM
There’s a bit more to it than just the HR efficiency, also depends on length of drain pipes between shower and HX, and whether connected to cold side of shower and cold feed to tank or just one or the other, so system efficiency ends up less than heat exchanger efficiency.
Several of the units are Passivhaus certified so solid efficiency data from which you can do the calcs on whether they stack up economically. My vert set up more than halves the energy requirement for a typical shower.
January 15, 2025 at 3:07 PM
Several of the units are Passivhaus certified so solid efficiency data from which you can do the calcs on whether they stack up economically. My vert set up more than halves the energy requirement for a typical shower.