Geekzone: technology news, blogs, forums
Guest
Welcome Guest.
You haven't logged in yet. If you don't have an account you can register now.


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

#196790 12-Jun-2016 20:46
Send private message

I have a daikin central heating system and a positive air system in my new house. Is there any benefit in having both running? Iam thinking of setting up open hab and have couple of sensors around the house as the central heating is only appears to be using the temperature it can sense where the controller is located. If the positive air system has some benefit i can perhaps look at switching it on or off using openhab depending on the situation.


View this topic in a long page with up to 500 replies per page Create new topic
 1 | 2 | 3

mdf

mdf
2683 posts

Uber Geek

Trusted
Subscriber

  #1570714 12-Jun-2016 21:00
Send private message

They're for different things. Central heating heats and the positive pressure system essentially dries/dehumidifies the air. The central heating will be much more effective with dry air, as wet air hold more heat.

 

In terms of automation, our old DVS positive pressure system had some (basic) smarts about not circulating dry/roof air when the temperature in the roof was lower than that in the house (winter mode). Similarly, you could choose summer mode and it wouldn't circulate hotter air when the roof was hotter than the house. The winter/summer selection was manual though. If you wanted to get cleverer, you could have some kind of calendar/seasonal setting?


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1570812 13-Jun-2016 07:48
Send private message

You'd probably be better off with an integrated system, but changing would be expensive. Personally I run my cheap old PPV system on a timer, in summer I run it morning and evening, in winter I run it during the day. All year round I run it occasionally in the evening to reduce cooking smells, and in summer I might run it late at night. I can hear it and it bugs me slightly.

 

I would run the PPV system at different times from the heating system, otherwise you're just pushing  your warmed air out of the house.


 
 
 
 


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1570813 13-Jun-2016 08:01
Send private message

Thanks, i dont have a temperature sensor in the roof at the moment so need to find something that will work with openhab. It would make sense to not run the PPV if the roof air temperature is less than the house unless i want to cool the house down. With turning the PPV off at night during winter, arent you not making use of any hot air sitting in your roof space?


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1570814 13-Jun-2016 08:08
Send private message

I don't use the air from the roof cavity any more. I have a very old house, the ceiling cavity is filled with dust, rat droppings (from before I owned the house), cobwebs, etc. The white sock filter went black within a few weeks of putting a new filter in. I extended the intake so it now draws fresh clean air from outside the house. In winter you have to turn it off around 4pm before people light fires otherwise your house smells like smoke. It did give the house a small boost in temperature, but not enough to be worth it. But once the sun goes down the roof temperature drops to be the same as outside quickly - I put temperature sensors up there to check.

 

PPV vendors tell bald faced lies in their sales pitches.


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1570865 13-Jun-2016 10:26
Send private message

Been doing some additional research. Some interesting facts:

 

The New Zealand Building Code requires homes to ventilate using outdoor air to maintain air purity. Ventilation systems that draw air from the roof space and not directly from outside do not comply with ventilation standard NZS4303:1990 "Ventilation for acceptable indoor air quality". They cannot be used to comply with the Building Code Acceptable Solution for ventilation.

 

and, a research report on ventilation systems states:

 

An ideal control system for forced air delivery from the roofspace clearly needs to take account of the temperature and humidity in both spaces. With this data, the system will be able to determine when operation will reduce the relative humidity in the building.

 

My PPV system doesnt appear to be getting the outdoor air at all :)


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1570867 13-Jun-2016 10:29
Send private message

It cost $50-$100 to get extra ducting and an external vent thingy to change my ventilation system. The vendor told me it wouldn't work, the motor wasn't powerful enough, but it works fine.


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1571688 14-Jun-2016 14:28
Send private message

It gets bit interesting. I had another look and i can see two circular duct fans pulling in air into the roof from outside. The ducts in each room has those foil pipes leading to where the cirular duct fans are but they are just sitting there, not connected to anything. Is there any reason for that (besides letting heat escape into the roof space) or has the installer not finished the job.


 
 
 
 


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1571692 14-Jun-2016 14:31
Send private message

t0ny:

 

It gets bit interesting. I had another look and i can see two circular duct fans pulling in air into the roof from outside. The ducts in each room has those foil pipes leading to where the cirular duct fans are but they are just sitting there, not connected to anything. Is there any reason for that (besides letting heat escape into the roof space) or has the installer not finished the job.

 

 

Can you show a photo? Sounds to me like the installer hasn't done their job. You're not getting any forced air ventilation and you've got big holes in the ceiling.


mdf

mdf
2683 posts

Uber Geek

Trusted
Subscriber

  #1571694 14-Jun-2016 14:32
Send private message

t0ny:

It gets bit interesting. I had another look and i can see two circular duct fans pulling in air into the roof from outside. The ducts in each room has those foil pipes leading to where the cirular duct fans are but they are just sitting there, not connected to anything. Is there any reason for that (besides letting heat escape into the roof space) or has the installer not finished the job.



If I read that right, that sounds completely dumb. Ducts to nothing? Photo?

mdf

mdf
2683 posts

Uber Geek

Trusted
Subscriber

  #1571696 14-Jun-2016 14:33
Send private message

mdf:
t0ny:

It gets bit interesting. I had another look and i can see two circular duct fans pulling in air into the roof from outside. The ducts in each room has those foil pipes leading to where the cirular duct fans are but they are just sitting there, not connected to anything. Is there any reason for that (besides letting heat escape into the roof space) or has the installer not finished the job.



If I read that right, that sounds completely dumb. Ducts to nothing? Photo?


And sorry I didn't mean that as it sounded. Installation = dumb, not the question.

t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1571697 14-Jun-2016 14:36
Send private message

Here goes:

 

 

You can see the three pipes sitting on the ceiling with the two duct fans above it


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1571714 14-Jun-2016 14:53
Send private message

I think we need a wider picture. I can't make much sense of that.


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1571717 14-Jun-2016 14:58
Send private message

Pretty dark up there and the camera flash doesnt get the whole area. Basically, the pipes from each room merge as per below:

 

 

Then one end of it is sitting on the cieling as per the other pic above. Two of the silver pipes connect from outside to the duct fan


timmmay
16529 posts

Uber Geek

Trusted
Subscriber

  #1571723 14-Jun-2016 15:07
Send private message

Sound be a fan sucks in air from somewhere, pushes it into ducting that goes into each room. Sounds like the didn't connect the ducts to the fans. Maybe you could draw a diagram, because it sounds like what you're saying is the fans spin away but do nothing...


t0ny

306 posts

Ultimate Geek

Lifetime subscriber

  #1571742 14-Jun-2016 15:20
Send private message

Hope this makes more sense:

 

 

     

  1. Shouldn't the outside air be filtered? Is it hard to put in a sock filter in there?
  2. Should the outlet from the duct fan be connected to the pipe that is lying below the duct fan?

 1 | 2 | 3
View this topic in a long page with up to 500 replies per page Create new topic





News »

Huawei launches IdeaHub Pro in New Zealand
Posted 27-Oct-2020 16:41


Southland-based IT specialist providing virtual services worldwide
Posted 27-Oct-2020 15:55


NASA discovers water on sunlit surface of Moon
Posted 27-Oct-2020 08:30


Huawei introduces new features to Petal Search, Maps and Docs
Posted 26-Oct-2020 18:05


Nokia selected by NASA to build first ever cellular network on the Moon
Posted 21-Oct-2020 08:34


Nanoleaf enhances lighting line with launch of Triangles and Mini Triangles
Posted 17-Oct-2020 20:18


Synology unveils DS16211+
Posted 17-Oct-2020 20:12


Ingram Micro introduces FootfallCam to New Zealand channel
Posted 17-Oct-2020 20:06


Dropbox adopts Virtual First working policy
Posted 17-Oct-2020 19:47


OPPO announces Reno4 Series 5G line-up in NZ
Posted 16-Oct-2020 08:52


Microsoft Highway to a Hundred expands to Asia Pacific
Posted 14-Oct-2020 09:34


Spark turns on 5G in Auckland
Posted 14-Oct-2020 09:29


AMD Launches AMD Ryzen 5000 Series Desktop Processors
Posted 9-Oct-2020 10:13


Teletrac Navman launches integrated multi-camera solution for transport and logistics industry
Posted 8-Oct-2020 10:57


Farmside hits 10,000 RBI customers
Posted 7-Oct-2020 15:32









Geekzone Live »

Try automatic live updates from Geekzone directly in your browser, without refreshing the page, with Geekzone Live now.


Support Geekzone »

Our community of supporters help make Geekzone possible. Click the button below to join them.

Support Geezone on PressPatron



Are you subscribed to our RSS feed? You can download the latest headlines and summaries from our stories directly to your computer or smartphone by using a feed reader.

Alternatively, you can receive a daily email with Geekzone updates.