HRV or DVS

Which is the best way to go please.

Waste of money.

What's the actual problem?

I am with johotech. Open the windows every now and then. Do not dry clothes in the house. Put DPC on the ground if your house is on piles. Insulate and heat the house.

ventilation systems have there uses and there drawbacks.
check to see if you actually need one. fixing sources of water is the first thing.

if you do need one then i would stay away from HRV due to the cost. they are expensive. theres quite a few companies around and also different systems. need to use a system that works with the house.

Talk to a local heating and ventilation place. One I used to work for could install a ducted fan for a fraction of the cost of HRV etc

#3+4 are on the money, but.
Our own house is kept warm with two wood fires, heat transfer to the bedrooms, kitchen and bathroom have ventilation fans, washing hung under carport in winter.
We are not in a gully and are north and west facing, so get most all day sun.
I was totally skeptical about them.
Tried one after a cousin installed theirs.
House started changing in two days, my breathing is normal now in the mornings.
I'm on oxygen filter system (CPAP) while asleep and the house particles would have me sneezing for 30-45 minutes each morning.
(We also installed one for our tenants because their kids are asthmatics, same results)
Looked at others and went with HRV.
Our Hamilton rental is smaller, so we went with a deal on Smart Vent.
Good, but not as good.
Our house was $3500.
1st rental was $4500, included bathroom fan.
2nd rental was $1500 and son got a friend to install it for us.
What we noticed was HRV had more and bigger vents.
Cost to run is about the same as a light bulb, about $30/mth.
What we saved on was the amount of firewood we went through during winter, from 3-4 baskets a night to one most nights, 2 on really cold nights.

There isn't a "one solution suits all" answer - which is what HRV tries to promote.

$3500 for a metal box with a fan and filter, and half a dozen lengths of duct, for or five $30 grilles, and a little control unit, isn't good value for money.

I've installed A/C systems for 30 years - and I can tell you there is less than $1000 worth of parts, and way less than $1000 for installation - probably more like $600 - so the company makes around 100% profit on every system.

What people need to find out, is what their particular problem is. Every house is different. Wood, brick, old, new, slab on the ground, damp under the sub-floor etc etc.

Plus, people live totally differently - some use a lot of heating and pay a lot for energy - others can't afford that and might not heat their house over 15-16deg for example. Or dry their clothes inside, or don't have ventilation in the kitchen or bathroom.

There are so many threads about damp houses. So many comments about "warm and dry" houses - people get brainwashed. But if people can't afford, or don't want to pay for heating, then no politician is going to make houses "warm and dry" and neither is an HRV.

As I asked #2, What's the actual problem?

And Smallwoods, it's great that you found an improvement - but for every success story, I bet there is another story of regret and feeling ripped off.

Totally agree Jono, and I tried for years to dismiss them as nonsense.
Problem, there's not enough of YOU to be all over the country.
Hence we did ALL the other stuff before installing the HRV system.
As the wife said, we had spent way more to get nowhere.
I couldn't argue on that point. LOL.

Happy wife, happy life. What more can you do.

Been there done that in a few different parts of the North Island.

Done all the insulation & open windows stuff & then seen or had (depending on mine or friends place) either DVS or HRV installed.

Big difference after 6 months to 1 year in overall warmth & a lot less heating required.

HRV definitely the better system but very expensive.
DVS cheaper but not as good by a noticeable margin.

Both systems well suited for older weatherboard homes simply because of the difference in original insulation systems compared to homes in the last 10 years.

No they don't. Our salesman asked us plenty of questions about why we thought we needed a ventilation system, inspected the house to find out why, and then explained the options they could provide. Many of the extras they have we didn't need (heating etc.) and he didn't push it.

Within a couple days of install our condensation issues were gone - three years on and still great. Noticed no increase in our power consumption either.