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The problem is there are conflicting problems with energy efficiency. How much energy is used to build and maintain the building. Can the building function as

The problem is there are conflicting problems with energy efficiency. How much energy is used to build and maintain the building. Can the building function as a building people want to use - if just sits empty its a huge waste of energy. Removing all the windows would help but wouldn't be very appealing. And lastly ventilation is probably of of the most tricky, it's very easy to create an energy efficient sealed box, but how do you create a healthy environment - older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape. The answer is normally a complex HVAC system but that then uses power and requires maintenance.

Robotbeat 5y ago
A good heat exchanger with the outside air helps.
- bregma 5y ago
  It sure helps legionella, influenza, and coronavirus to spread.
  - netjiro 5y ago
    Plenty of options to fix that problem. E.g. a cheap addition to existing installations: aircode.se Limited but sane research from around 2013(?) points to even cheaper options of ventilation treatment.
  - throw0101a 5y ago
    Legionella generally comes from fresh water sources. If you're worried about it filter your water. Airborne contagions do not spread from bringing in outside air and tempering it via an HRV/ERV. The risks rise when you do not bring in fresh air but rather recirculate indoor air, but these can be reduced by using MERV 13+ filters: * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127325/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127325/
  - Robotbeat 5y ago
    Use a HEPA filter. But even without a HEPA filter, for most shared indoor spaces (restaurants), it’d better to exchange with the outside air than to recirculate unfiltered inside air.
- netjiro 5y ago
  Even a simple design gives 80% capture
throw0101a 5y ago
> And lastly ventilation is probably of of the most tricky, it's very easy to create an energy efficient sealed box, but how do you create a healthy environment ASHRAE 62.1 and 62.2, "Ventilation for Acceptable Indoor Air Quality": * https://www.ashrae.org/technical-resources/bookstore/standards-62-1-62-2 https://www.ashrae.org/technical-resources/bookstore/standar... > The answer is normally a complex HVAC system but that then uses power and requires maintenance. > older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape. Drafty buildings are bad. The air comes in through random cracks and crevices, which may have mold and which also allow bugs and rodents to enter. The rodents may leave droppings, which the flowing draft may then pick up particles from. There are no health benefits to that. > The answer is normally a complex HVAC system but that then uses power and requires maintenance. The drafty house you laud above will also use power: in the winter air that was heated will leak out, and the cold air that comes in will have to be brought up to temperature; in the summer the cooled air will escape and the hot (and perhaps humid) air will then need to dealt with to make the building comfortable. And that doesn't include dealing things in the air like dust and pollen (plus the above mentioned critters). Or you can install some ducting to remove stale air from the house (esp. bathrooms and kitchens), and introduce fresh air (esp. to bedrooms) that is first filtered (MERV 13+) and then tempered via an ERV/HRV core so there's a minimum of re-conditioning needed. The main source of maintenance is the changing of the filter(s). And running an ERV/HRV will use less energy (W or BTU) than re-conditioning the leaky air. This is a solved problem: build tight, ventilate right. After air tightness throw on some insulation (while reducing thermal bridging) and you can have a house that uses minimal energy in dealing with environmentals. You just have to make the effort up-front when designing it (or when doing a renovation/retrofit).
- docflabby 5y ago
  I don't disagree the problem is solved - I the problem in the UK is humidity is quite high most of the time and most houses don't have HVAC and there seems to be a complete lack of knowledge around ventilation - very little thought goes into it for domestic properties, so you send up with these sealed up houses under the guise of "energy efficiency" which makes people ill though mold growth due to lack of air flow. It's probably also contributed to the spread of covid 19.
JohnJamesRambo 5y ago
I think this is overlooked far too often. Through various programs, my mom went crazy on the insulation and energy efficiency in her old ranch style house but didn’t add an air exchanger. We realized we felt like crap there and measured the CO2 and it was hitting over 3000 ppm! https://www.kane.co.uk/knowledge-centre/what-are-safe-levels-of-co-and-co2-in-rooms https://www.kane.co.uk/knowledge-centre/what-are-safe-levels... I’m horrified to think of all the poor people in these programs that are probably feeling bad but have slightly better energy bills. Good health is the most important quality we have. There need to be energy conserving air exchangers put in with each tight house made. That’s the best of both worlds.

Robotbeat 5y ago

A good heat exchanger with the outside air helps.

bregma 5y ago
It sure helps legionella, influenza, and coronavirus to spread.
- netjiro 5y ago
  Plenty of options to fix that problem. E.g. a cheap addition to existing installations: aircode.se Limited but sane research from around 2013(?) points to even cheaper options of ventilation treatment.
- throw0101a 5y ago
  Legionella generally comes from fresh water sources. If you're worried about it filter your water. Airborne contagions do not spread from bringing in outside air and tempering it via an HRV/ERV. The risks rise when you do not bring in fresh air but rather recirculate indoor air, but these can be reduced by using MERV 13+ filters: * https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127325/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7127325/
- Robotbeat 5y ago
  Use a HEPA filter. But even without a HEPA filter, for most shared indoor spaces (restaurants), it’d better to exchange with the outside air than to recirculate unfiltered inside air.
netjiro 5y ago
Even a simple design gives 80% capture

throw0101a 5y ago

> And lastly ventilation is probably of of the most tricky, it's very easy to create an energy efficient sealed box, but how do you create a healthy environment ASHRAE 62.1 and 62.2, "Ventilation for Acceptable Indoor Air Quality": * https://www.ashrae.org/technical-resources/bookstore/standards-62-1-62-2 https://www.ashrae.org/technical-resources/bookstore/standar... > The answer is normally a complex HVAC system but that then uses power and requires maintenance. > older buildings are drafty but it comes with health benefits and keeps the building dry by allowing moisture to escape. Drafty buildings are bad. The air comes in through random cracks and crevices, which may have mold and which also allow bugs and rodents to enter. The rodents may leave droppings, which the flowing draft may then pick up particles from. There are no health benefits to that. > The answer is normally a complex HVAC system but that then uses power and requires maintenance. The drafty house you laud above will also use power: in the winter air that was heated will leak out, and the cold air that comes in will have to be brought up to temperature; in the summer the cooled air will escape and the hot (and perhaps humid) air will then need to dealt with to make the building comfortable. And that doesn't include dealing things in the air like dust and pollen (plus the above mentioned critters). Or you can install some ducting to remove stale air from the house (esp. bathrooms and kitchens), and introduce fresh air (esp. to bedrooms) that is first filtered (MERV 13+) and then tempered via an ERV/HRV core so there's a minimum of re-conditioning needed. The main source of maintenance is the changing of the filter(s). And running an ERV/HRV will use less energy (W or BTU) than re-conditioning the leaky air. This is a solved problem: build tight, ventilate right. After air tightness throw on some insulation (while reducing thermal bridging) and you can have a house that uses minimal energy in dealing with environmentals. You just have to make the effort up-front when designing it (or when doing a renovation/retrofit).

docflabby 5y ago
I don't disagree the problem is solved - I the problem in the UK is humidity is quite high most of the time and most houses don't have HVAC and there seems to be a complete lack of knowledge around ventilation - very little thought goes into it for domestic properties, so you send up with these sealed up houses under the guise of "energy efficiency" which makes people ill though mold growth due to lack of air flow. It's probably also contributed to the spread of covid 19.

JohnJamesRambo 5y ago

I think this is overlooked far too often. Through various programs, my mom went crazy on the insulation and energy efficiency in her old ranch style house but didn’t add an air exchanger. We realized we felt like crap there and measured the CO2 and it was hitting over 3000 ppm! https://www.kane.co.uk/knowledge-centre/what-are-safe-levels-of-co-and-co2-in-rooms https://www.kane.co.uk/knowledge-centre/what-are-safe-levels... I’m horrified to think of all the poor people in these programs that are probably feeling bad but have slightly better energy bills. Good health is the most important quality we have. There need to be energy conserving air exchangers put in with each tight house made. That’s the best of both worlds.