Moister master, hrv, dvs. Which one is best

[freezinhot]

I know its on this site somewhere, but in your HO which one is REALLY the best, many companies will preach theirs is the best, but how can you really be sure. Is it the features to go by or the amount of moisture that can be taken from the air.

FH

[muppet]

Don't forget Smart Vent, who have just started advertising on TV.

[Odin]

I have an HRV and that is great. We are 5-7 people in the house and only on rare occasion have a minimal amount of moisture on a big expanse of kitchen windows when cooking. I checked the bathroom window which has exposed wood on the frame from before the HRV and the wood is bone dry (remember 5-7 people showering here).
I don't know about the others. The atvantage i think with the HRV is that it has a went in each room and the dry air get everywhere. Down sides would be that electric heating for it is really expensive (1400+ pr room). But the install should be no more that 2500 - 3500.
I am glad we have it even though it dosn't heat the house in winter as much as i expected. The house does get heated but more so in sping and autumn and that does save quite a bit on heating. and it cools the house on sommer evenings witch is also nice.

[Heg]

Judging by the latest article in the press -most of them are a con. We have two HRV and a Healthaire system in three of our rentals. No fancy bits and pieces, just air re-circulation. They seem to do an ok job. A friend of mine had one ripped out, as it was blowing freezing cold air into the house on dull days. Once NZ homes get proper insulation and double glazing, these firms will go out of business.

[Odin]

The airflow on the HRV can be ajusted. It never stops (though you can turn it off) but it can be adjusted so the airflow is minimal while the temp in the roof is "undesirable" as in to high or to low. When the temp in the roof is more desirable than the temp in the house it will then blow harder.
We live and a villa and it certainly help with moister there. I know insullation, double glasing and a general fix of windows and door leaks would be great too but that would be quite a bit and the moister would still be in the house from cooking, breathing and showering.

[rockran]

I have a HRV and it works really well for me. No moisture at all. I don't use it for heating.

[Selamat]

A lot of people I know have removed DVS systems because they have proved to be too cold and have replaced them with HRV, which are definitely warmer. For rentals such systems are great because a lot of tenants seem to like living with closed doors and windows and they definitely prevent mould, and most condensation from occurring. With HRV, even if tenants turn it off, the system will automatically come back on after a set period.

[Wayne]

Judging by the latest article in the press -most of them are a con. We have two HRV and a Healthaire system in three of our rentals. No fancy bits and pieces, just air re-circulation. They seem to do an ok job. A friend of mine had one ripped out, as it was blowing freezing cold air into the house on dull days. Once NZ homes get proper insulation and double glazing, these firms will go out of business.

The article didn't say that the units were a con - just that some of the advertising was wrong. They are not heaters (heaters can be added) and just circulate air from the roof space. Generally this air is warmer than outside (debatable in the dead of night) and drier.

[Wayne]

A lot of people I know have removed DVS systems because they have proved to be too cold and have replaced them with HRV, which are definitely warmer. For rentals such systems are great because a lot of tenants seem to like living with closed doors and windows and they definitely prevent mould, and most condensation from occurring. With HRV, even if tenants turn it off, the system will automatically come back on after a set period.

The only reason I can think that a DVS would be cold but an HRV warm would be because a heater was installed in the HRV. I saw an article (can't find referance) that suggested that the cost of heating with a HRV would be huge. A 1kw heater (which I think is all they have) will do bugger all - take the chill off the air - at a great cost. We have a fully ducted heat pump central heating in our house and it takes over 4kw to heat the place (that is 4kw electricity and 12-15kw heat) so I can't imagine that 1kw would do much.

[Wayne]

Once NZ homes get proper insulation and double glazing, these firms will go out of business.

Moisture in the home is not a matter of insulation - it is a matter of air circulation and the modern home doesn't have enough of it.

[Wayne]

Don't forget Smart Vent, who have just started advertising on TV.

Smart Vent have been around for a while. I put one in 3 yrs ago after they were promoted to the trade. Basically it was - buy one of these for $1200 and sell to the punter for $3k with 4 hrs of work installing, good money making for the electrician.

[Odin]

Installing in rentals

How about depreciation ? If a system is installed in a rental what kind of depreciation could that give ? I'm looking at a cheap rental to upgrade a bit for tenant comfort and therefore longer stays.

[rueben]

Judging by the latest article in the press -most of them are a con. We have two HRV and a Healthaire system in three of our rentals. No fancy bits and pieces, just air re-circulation. They seem to do an ok job. A friend of mine had one ripped out, as it was blowing freezing cold air into the house on dull days. Once NZ homes get proper insulation and double glazing, these firms will go out of business.

Do you have a link to the press article?

Its not correct that we won't need ventilation with proper insulation and double glazing - this means we have even less airflow and moisture builds up from just living, showering etc. Just look at overseas countries like canada - they build with ventilation systems, centrally heated and hugely insulated.

The moisture is still there - it just doesn't show on the windows. More humidity means more mould and dust mites.

I love my HRV - if I was looking again I would ask about the microns it filters to, what kind of filter, cost to run (don't get one with a heater in it - just inefficient). I would also look at the electronics - if the speed of the fan increased or decreased depending on the conditions in the roof. (thats why people pull out their DVS and install HRV). And their after sales service, guarantees.

HRV warms when there is warm air in the roof - so I don't need heating during the day in my house when it is a half decent frosty day outside. Before HRV my bedrooms were around 10 degrees all day - now they can reach 18-20 degrees very regularly. Then I use my "primary heat source" for heating in the evenings to "top it up".

[Selamat]

I would suggest that you get the facts from the various manufacturers themselves. My personal finding is that HRV is not only warmer, but is actually cheaper to run than DVS

[Wayne]

I would suggest that you get the facts from the various manufacturers themselves. My personal finding is that HRV is not only warmer, but is actually cheaper to run than DVS

I wonder why the cost differance? Does your HRV have a heater?