Calf House Ventilation - Vents or PPTV

[Xiaomi]

I've got a small shed 30ft x 28ft which I'm converting to house approx 12 - 14 bought in calves.

The shed is currently fully enclosed. My initial plan is to vent the gable with Yorkshire Cladding and raise a sheet on the roof to vent.

Is there any point considering a PPTV (Positive Pressure Tube Ventilation) type system for this size of a shed? The site would be exposed - which is why I am opting against space boarding. I just thought that for the small size of the shed that there might be less work involved in getting a PPTV system installed (can do this myself) and minimise the amount of butchering that I need to do to the shed structure.

From speaking to others, the shed should be sufficiently 'leaky' that nothing else would be needed along side the fan and tube - i.e. to expel the stale air.

 

[ringi]

Remember young calves are unlikely to generate enough heat for the air to rise out of high level vents unlike with older cows.

 

[Xiaomi]

Remember young calves are unlikely to generate enough heat for the air to rise out of high level vents unlike with older cows.

I had read that somewhere - so a vented ridge is a waste of time for young calves. Would Yorkshire Cladding (or PPTV) be sufficient on its own then?

 

[ringi]

I had read that somewhere - so a vented ridge is a waste of time for young calves. Would Yorkshire Cladding (or PPTV) be sufficient on its own then?

A vented ridge would let wind in/out on some days when combined with other openings. I yet to see any guidance on ventilation that will give definite answers in what will work without also allowing too many drafts.

However I expect a correctly sized PPTV system with no high level openings in building would give predictable good results, but it costs money to install and have running costs.

I expect well spaced out individual or pair calve hatches in a very well ventilated "building" is the lowest risk option.

 

[Xiaomi]

These calves will be in two pens with slight overhang at the rear for 'shelter' from draughts. Good fall in floor to aid drainage.
They will be behind individual penning at the stage they are purchased.

Really don't know what to do here - I think a PPTV system will be prohibitively expensive as the main components will be the same as a large scale system.

 

[Bangoverthebar]

I extended my calf shed this summer. It will be fully open facing north, has a 3ft roof gap facing south and space boarding on half of the west facing side. I want loads of airflow.
46x30

I make sheltered sections within the shed with a canopy and low sheeting around the canopy it allows calves to be out of the wind if sheds get draughty.
I also have a 30x30 open air yard calves use in front of shed. Shed will hold 60 babies to 4 week old calves. I'm putting in an adlib feeding system for calves for the spring also.

 

[crashbox]

These calves will be in two pens with slight overhang at the rear for 'shelter' from draughts. Good fall in floor to aid drainage.
They will be behind individual penning at the stage they are purchased.

Really don't know what to do here - I think a PPTV system will be prohibitively expensive as the main components will be the same as a large scale system.

Try it with just boarding first, I suspect you'll be fine.

Stick a straw bale in the middle for them to nestle round in case of draft.

Don't look for problems before you start, they will show themselves.

 

[ringi]

There are government grants https://www.gov.uk/government/publi...g-for-health-and-welfare-grant-specifications but look like a trail this year.

See also https://ahdb.org.uk/knowledge-library/youngstock-housing-temperature-humidity-and-ventilation

 

[Xiaomi]

I'm not sure what to do I was walking around the shed this morning and seen that with it all fully closed that a cobweb at the eaves above where the calves would be lying was moving in the breeze. I think there might be sufficient leakage on a breezy and upwards day to vent the shed. Seemed to be stable at calf height, but I can't confirm that yet.
I don't think that there would be many calm days here during autumn. I might get an anemometer and see what it is picking up.

The specs say I should have 0.48m2 vents on two walls and 0.48m2 on roof (assuming 12 calves). What I'm concerned about is that on a breezy/blustery day that there is sufficient gaps in the structure (doors gaps, under corrugations, etc) that combined with cladding there would be a draught issue in the shed - as the shed is located in an exposed location.

The volume of the shed would be around 225m3 to the eaves. So according to the link from @ringi I've more more than sufficient airspace for them.

The floor has a slope of approx 1 in 8 - a lot more than the 1 in 20 from the link, but nothing I can do about that - at least it is steeper which will aid runoff. I've seen a recommendation that cattle should not be house in an area with a slope of more than 1 in 10, but I'll just have to work with what I have.

 

[Jimfandango]

Light a bucket of damp hay in the shed and see where the smoke goes. That should show up any potential issues

 

[Xiaomi]

Back looking at this:

Youngstock housing – Temperature, humidity and ventilation | AHDB

Your dairy youngstock housing

ahdb.org.uk

The outlet area should be a minimum of 0.04 m² per calf and typically at least 1.5 m above any inlet. Inlet areas should be a minimum of 0.08 m² per calf (0.04 m² in each sidewall).

Am I correct in thinking that for Yorkshire boarding, the spaces between each board should sum to 0.08m2 per calf - as opposed to a cladding area of 0.08m2 per calf.

 

[Xiaomi]

Light a bucket of damp hay in the shed and see where the smoke goes. That should show up any potential issues

I've bought some smoke pellets for that job. Probably one of the very few useful things I've seen from Tom Pemberton videos.

 

[Xiaomi]

This calf shed is on an exposed site.

Is it wise in my scenario to follow the guidance on installing this type of cladding to have a 2" gap with 6" boards?

View attachment 1216243

I've read the blurb about how much gap is required per calf for inlet and outlet. My thinking here is to go for a smaller than recommended overall inlet and outlet area - as I can increase it more easily than decrease it.

Has anyone here used this type of cladding? Do you get a draft with 2" spacing?

 

[bean]

This calf shed is on an exposed site.

Is it wise in my scenario to follow the guidance on installing this type of cladding to have a 2" gap with 6" boards?

View attachment 1216243

I've read the blurb about how much gap is required per calf for inlet and outlet. My thinking here is to go for a smaller than recommended overall inlet and outlet area - as I can increase it more easily than decrease it.

Has anyone here used this type of cladding? Do you get a draft with 2" spacing?

Looked at a calf unit with boards each side of the side rails, 2 inches gap with a 5 by 3 rails. Looked good and was blocking the weather well

 

[crashbox]

This calf shed is on an exposed site.

Is it wise in my scenario to follow the guidance on installing this type of cladding to have a 2" gap with 6" boards?

View attachment 1216243

I've read the blurb about how much gap is required per calf for inlet and outlet. My thinking here is to go for a smaller than recommended overall inlet and outlet area - as I can increase it more easily than decrease it.

Has anyone here used this type of cladding? Do you get a draft with 2" spacing?

Go the the right hand option (double boards)

 

[Xiaomi]

Go the the right hand option (double boards)

That's what I'm putting in. Space boarding won't work with me as the shed is too exposed.
The docs state 0.08m2 inlet area and 0.04m2 outlet area per calf.
I'm thinking of reducing that due to site exposure to prevailing wind.

Just wondering if 2" air gap and 2" between the double row of boards would be too much in my location.

Everyone here has space boarding, but incorrectly calls it Yorkshire cladding.

 

[Wesley]

I’ve seen it done where the inside vertical boards aren’t fixed to the rail but made as a separate panel that can slide side to side allowing you alter the ventilation.

 

[Xiaomi]

I’ve seen it done where the inside vertical boards aren’t fixed to the rail but made as a separate panel that can slide side to side allowing you alter the ventilation.

That's a great idea. I was thinking of the poverty spec version - using screws so that i could alter the gaps if I felt it was too wiide.


As an aside to this, I've read that calves are unable to generate enough heat to create a stack effect - so why do the docs on building a calf shed all define usage of an outlet at the apex?

 

[ringi]

That's a great idea. I was thinking of the poverty spec version - using screws so that i could alter the gaps if I felt it was too wiide.


As an aside to this, I've read that calves are unable to generate enough heat to create a stack effect - so why do the docs on building a calf shed all define usage of an outlet at the apex?

When the outlet is correctly shaped, then wind from any direction will create a low pressure zone over the ridge outlet. Also if the inlets are not on all sides or a side is blocked by other buildings the ridge outlet will allow an airflow.

 

[crashbox]

That's what I'm putting in. Space boarding won't work with me as the shed is too exposed.
The docs state 0.08m2 inlet area and 0.04m2 outlet area per calf.
I'm thinking of reducing that due to site exposure to prevailing wind.

Just wondering if 2" air gap and 2" between the double row of boards would be too much in my location.

Everyone here has space boarding, but incorrectly calls it Yorkshire cladding.

It's not too much.

Better to have plenty of airflow (no draught at calf level) and plonk some straw bales in the pens for the calves to huddle round.

I'm on the south coast, mind.