3 ms·

It depends massively on your climate and how air in your house is managed. If you live somewhere which is significantly colder outside than in (e.g. 0-5C out,

It depends massively on your climate and how air in your house is managed. If you live somewhere which is significantly colder outside than in (e.g. 0-5C out, 21C inside) heating outside air to comfortable temperatures will greatly decrease humidity. Couple this with a system which circulates air, or even exchanges inside&outside air and you will have incredibly low humidity inside. I live somewhere which often sees 10-15C @ 80% humidity over winter, and the only air circulation in my house is from opening doors/windows. 70% internal humidity @21C is incredibly common. It takes a bit of moisture management to keep it below 60%.

newaccount74 4y ago
Ventilation with heat recovery sounds like it could work in those conditions, but just barely. 80% @ 15C would turn into 55% @ 21C.
- cameronh90 4y ago
  Unfortunately, very few homes in the UK have any air ducting. I'm looking at installing a MHRV system at the moment, but planning the ducts is a nightmare. Brick walls, lintels and structural joists everywhere with no headroom between floor and ceiling. We absolutely should be doing it in new builds though, and we're not.
  - nsteel 4y ago
    New build flats have some air ducting. At least, mine did in two rooms (it wasn't for AC). But maybe you meant new build houses.
  - hedora 4y ago
    That sounds rough. Consider putting in air to air mini-splits instead, and leaving window cracked open, etc. As a bonus, each room will get its own thermostat, and cooling / heating. The mini-split will only require coolant lines, and will have a sufficiently high coefficient of power that this + whatever ventilation exists might use less energy than heating with natural gas (or resistive electric), even with the loss of efficiency from not using heat exchangers. (Doing both things would be much better, of course. Retrofitting is hard.)
pbj1968 4y ago
Define “massively.” Sounds like a Reddit-esque waffle word like “wildly” or “dramatically.”

newaccount74 4y ago

Ventilation with heat recovery sounds like it could work in those conditions, but just barely. 80% @ 15C would turn into 55% @ 21C.

cameronh90 4y ago
Unfortunately, very few homes in the UK have any air ducting. I'm looking at installing a MHRV system at the moment, but planning the ducts is a nightmare. Brick walls, lintels and structural joists everywhere with no headroom between floor and ceiling. We absolutely should be doing it in new builds though, and we're not.
- nsteel 4y ago
  New build flats have some air ducting. At least, mine did in two rooms (it wasn't for AC). But maybe you meant new build houses.
- hedora 4y ago
  That sounds rough. Consider putting in air to air mini-splits instead, and leaving window cracked open, etc. As a bonus, each room will get its own thermostat, and cooling / heating. The mini-split will only require coolant lines, and will have a sufficiently high coefficient of power that this + whatever ventilation exists might use less energy than heating with natural gas (or resistive electric), even with the loss of efficiency from not using heat exchangers. (Doing both things would be much better, of course. Retrofitting is hard.)

pbj1968 4y ago

Define “massively.” Sounds like a Reddit-esque waffle word like “wildly” or “dramatically.”