HRV home ventilation 'vs' the Air Movement Solutions system -

Forums › Home Workshop DIY › HRV home ventilation 'vs' the Air Movement Solutions system -

1 | 2 | 3

1543 posts

Uber Geek

ID Verified

Trusted

#346242 29-Jun-2010 09:46

+1 HRV, had one installed around 2 years ago. Made a considerable difference, almost entirely removed condensation on windows on cold mornings. House feels noticeably drier.
Also installation was good, follow up visit and measured moisture content in walls before and after etc.

wmoore

510 posts

Ultimate Geek

#346261 29-Jun-2010 10:32

redjet: We put in an HRV system just over 16 months ago and have to say it's well worth the money.

I wish people would stop referring the brand name HRV as a system. HRV the company sells PPV systems not
Heat recovery ventilation systems as in the likes of cleanaire.
They guy who started HRV originally worked for Healthaire as a sales rep, he thought he could do better so basically stole the tech that healthaire were using at the time and started his own company. Healthaire took him to court and I think an agreement was reached. A court search may find more details.

"In the end, it's not the years in your life that count. It's the life in your years." -
-- Abraham lincoln

Handsomedan

7285 posts

Uber Geek

ID Verified

Trusted

Subscriber

#346313 29-Jun-2010 11:53

I remember being told that story by the guy who started Healthaire...mad inventor type.

Nice chap. Very clever, too.

Handsome Dan Has Spoken.
Handsome Dan needs to stop adding three dots to every sentence...

Handsome Dan does not currently have a side hustle as the mascot for Yale

*Gladly accepting donations...

redjet

299 posts

Ultimate Geek

#346349 29-Jun-2010 13:39

wmoore:
redjet: We put in an HRV system just over 16 months ago and have to say it's well worth the money.

I wish people would stop referring the brand name HRV as a system. HRV the company sells PPV systems not
Heat recovery ventilation systems as in the likes of cleanaire.

I was referring to a "system" supplied by HRV - if you read the rest of my post you would have seen how I make other references to the company "HRV".

Red Jet Web Services
- Affordable websites for small businesses
- Google Email setup and Migrations

crispinb

2 posts

Wannabe Geek

#346737 30-Jun-2010 18:01

Thanks everyone for this discussion - I have found it very useful.
We have a large old villa and have recently been visited by HRV who do a very talented hard sell! Not that I object - it just makes me suspicious.
We have not much roof space as most of the roof has been used for bedrooms, however they do not seem to think this is a problem ... I am suspicious. I can not see how it will help a big old draughty villa to blow air in from the tiny roof cavity - might as well be blowing it in from the outside?
Also they advised installing one of the fans to blow from the roof cavity into the inhabited roof space immediately beside it which seems daft to me. There is some match-lining between the one and the other - what is the point?
Can anyone advise about this?
I am now pursuing the other heat exchanger options.
Thanks

Dingbatt

6755 posts

Uber Geek

Lifetime subscriber

#346782 30-Jun-2010 21:14

You might also want to consider the primary moisture sources in you house and what can be done about them.

I reckon the main sources are showers, cooking, clothes driers and humans. You can't do a lot about the last one because everybody needs to breathe, however effective removal to outside the house of the the other moisture does make a difference.
We have done the following to significant effect:
Having a range hood that vents to outside and using it when boiling the jug as well as when cooking.
Venting clothes drier exhaust to outside.
A totally enclosed shower with bathroom extractor to outside the house.

I came to the same conclusion as many of the posters above when it came to positive pressure ventilation systems. I would only ever consider one in conjunction with our heatpump and use it to flush the house out when the heating is off and everyone is out of the house at work/school.

From what I have seen of the HRV(PPV) it doesn't provide that level of control because even if you turn it off you are actually only pausing its operation and it restarts itself after a period of time (4 hours?). I do believe you can switch the DVS off (?).

“We’ve arranged a society based on science and technology, in which nobody understands anything about science technology. Carl Sagan 1996

Regs

4066 posts

Uber Geek

Trusted

Snowflake

#346833 1-Jul-2010 02:39

crispinb: .
We have a large old villa and have recently been visited by HRV
<snip>
I am now pursuing the other heat exchanger options.

how about telling us what you want a system for? Is your place Damp? Cold? Damp & Cold?

If you're just looking to heat up a cold house, you might be better off looking at a central heating system.

Sales Engineer
Snowflake
www.snowflake.com

about.me/nzregs
Twitter: @nzregs

Geese

1028 posts

Uber Geek
Inactive user

#346883 1-Jul-2010 09:42

Jaxson had a great post.

We have HRV's PPV system here, been installed 2 years. I guess with varying opinions, it all depends where in the country you live, and location of house.

I think its a bit hopeless. During the winter, it does not do a thing, literally, it never gets warm enough for it to turn on. We are in a south facing sloped section, which barely gets the sun, outside the drive/footpath/road is wet/frosty 24 hours a day during more than half of the year.

Typical winter mornings like today, after having the fire going for 15 hours (until 1am), and 3 electric heaters going (until 1 am), the inside temperature is 5 degrees. Humidity is 87%. So at the time of the year we need it the most it does nothing.

When it does go, I can't say it makes a noticable improvement, windows still condensated. I don't sit in my room and go wow, look at the condensation dissappearing or wow, look at the humidity level decreasing.

The fan is quite noisy, it can be heard anywhere in the house, and during summer it runs all night long. I find fan sounds pleasant, so I like it, but if fans drive you crazy then ours is really loud. Also it cannot be permanently turned off, only turned off for 8 hours, then it turns itself back on. So there is no escaping the fan at night unless you keep going and turning it off before bed.

When it was first installed I had no idea how it worked. I think a heat transfer kit to take heat from lounge and pump into bedrooms would have been far better value, and achieved more.

We did notice that once installed, it shifted the baseline of our powerbills up around >$5 <$10 per month. Our powerbill is more expensive during summer than winter as we have a wetback on the fire, but with so many power increases happening in last 2 years the >$5 <$10 figure is probably ~$10 by now per month. Not that this is a huge amount by itself, but in the context of our power usage (not including ~ $1.50/day line charges), it accounts for 12% of our monthly power usage.

Lee13

33 posts

Geek

#346903 1-Jul-2010 10:15

I recomend this NZ made NZ Idea's and aweome from kiwi's for kiwis
http://www.condensation.co.nz/welcome/

Jaxson

8042 posts

Uber Geek

Trusted

#346907 1-Jul-2010 10:25

I'm really into this topic, ties in a lot with what I do at work too plus the newer home we?ve just moved into. Technically there's not much stopping you making up a system of your own too. You only need to get a company involved if you want the fancy looking controls / controller pads etc, or a better heat exchanger/recovery type of technology.

New homes are very sealed, eg aluminium joinery with rubber seals, door draught seals applied etc. This prevents cold air leaking in, but prevents ventilation so this type of problem is only going to increase in the future.

Extract fans in bathrooms/rangehoods etc can only extract as fast as air can be drawn into the room. Just something to think about there.

It's been brought up before and needs to be considered: Where is the condensation coming from? Warm, humid air touching cold objects (windows mainly) will cause condensation. Ventilating or replacing the humid air by forcing it out is one option. The other options are to remove the source of humidity creation as much as possible or remove the cold objects, ie double/triple glazing etc.

Each has their pros and cons and in reality a combo approach is best. Money is the main hurdle so I think a good discussion like this really helps to share ideas before any one of us commits sort of thing. Any form of ventilating is going to push out hot air and replace it with cold air during winter. You can't do this without expecting your heating costs to increase. Also forced ventilating will only work well if air can leak out of your building easily to force the humid air out.

As an aside, the heat pump adverts sometimes refer to a dehumidifying component but it pays to remember that this doesn't occur during heating cycles (ie use during winter), which is when you need dehumidifying the most.

pseudogeek2009

66 posts

Master Geek

#355974 25-Jul-2010 07:35

I do think the PPV system made a difference in my house especially on a rainy day. Before my house used to be damp but after installing a similar system to HRV (Weiss), it made a difference. The house is not damp but it does bugger all for heating as it is blowing in cold air from the roof. By removing the dampness in your home it is suppose to be easier to heat up your house.
The reason for HRV and Weiss system being noisy as it is using a pulse skipping type of control for the motor. Both system uses split phase motor and using this type of control for the motor allows it to have a larger range of speed control over a triac method. The triac method is only limited to approx. 3 speeds while the phase skipping you can have approx. 10 speeds hence the reason for this type of control. The alternative is add some sort of dampers to the motor to reduce the vibration or change to a different type of control but for normal punters, it is unlikely you want to do this. As for DVS, I am not sure how their control works but they seem to use a different type of motor and it does seem quieter in my in-laws house.

timbosan

2159 posts

Uber Geek

#355979 25-Jul-2010 08:15

I have read comments about HRV, DVS, MM etc many times over, both and on consumer.org.nz, as well as overseas sites, and one thing I don't see much of are comments relating to the use of a traditional dehumidifier.

We have an old house (typical NZ weatherboard with no insulation in the walls, but we have batts on the roof and underfloor insulation), live in Auckland, so it can get very cold inside in winter.

A couple of months ago I bought a new dehumidified (a DeLonghi model, approx $500) to get rid of the moisture out of the air (DUH!) but it doesn't replace it with cold air from the roof or outside, and the air blown out of it is dry and 99% of the time warmer.

I have found that since buying this the heater has been used probably less than once at week, and then only in the mornings when I get up. The house it noticable dryer and warmer (where have I heard that before....).

Sure, I have the empty the water out, which can be as often as once a a day even in this weather, but for the cost compared to a DVS system (the type, not the brand) it was approx 1/4 or less of the price. And I can turn it off all together, change the fan speed, and I can see the results (in the water collected).

Why don't people consider these inside of the DVS/PPS type models? It would cost less to run than anything with an inline heater, there are no costs every 2 years to replace the filter (which costs nearly as much as a new dehumidifier), and I can move it room to room as the sources of moisture move (mainly people or near the bathroom).

I previously had a Mitsubishi dehumidifier, and it was nowhere as good, the reason I bought the DeLonghi was because it came top rated from consumer, and there is a noticable difference between the two.

I have thought about installing a permenent drain so I don't have to keep emptying it, removing one of the (small) negatives and getting another one so I don't have to move them around (which would still cost me less than a DVS type installation). I am not sure of the running costs but the power bill hasn't shot up or anything.

What do others think? Why don't more people just buy a good dehumidifier?

pseudogeek2009

66 posts

Master Geek

#355985 25-Jul-2010 08:52

The motor on HRV and weiss system is a 85W motor and it is not usually on full power.
My Weiss system is on 21% of the time so I think if you calculate the current, it should be pretty low compare to a dehumidifier. My Weiss system has four outlets so covers most area of my house and also it has an external inlet for fresh air to come in.

pseudogeek2009

66 posts

Master Geek

#355987 25-Jul-2010 09:10

I forgot to mention I can also turn it off and it also has an option for heaters but unsure of the efficiency and cost. Anyway, I have a wood burner and that seems to be suffice for warming up the house.

robbyp

1199 posts

Uber Geek

#356051 25-Jul-2010 13:02

My personal opinion is the main reason many of these ventillation systems have been successful, is due to them extensively marketing them on TV. Also they will usually do the 'Hard Sell' on you if you enquire about them, as their workers likely work on a commission basis. Personally I think many ventillation system s of that sort you could buy the parts and set up your own system, especially a basic heat transfer system between one room and another. I have seen people setup their own systems and they work well. A heat pump is also a better investment, if you don't already have one. Some people think these ventilltion systems will also heat or cool their house, but they usually take the dirty cold air from your roof space (Where your fibre glass insulation is) and pump it back into the house. The air in the roof space is usually cold in the winter, and hot in the summer, which is not the sort of air you want in your house. We had one of these ventillation systems installed about 10 years ago to reduce condensation, but it has had little effect, and it certainly has done nothing to heat or cool the house.

1 | 2 | 3