Fresh air

[Jimbo!]

Hi All

I read the other thread on fresh air with interest, hopefully you fine folk will spare me a minute of your time.

I have a summerhouse, 12ft x 12ft, block/render/plasterboard, upvc glazed. Unfortunately there was a balls-up by the glazing company and the windows were delivered without trickle vents which I specified.

There is a pair of french doors, and a floor-to-ceiling glazed wall with no openers. Is air conditioned hence only the doors.

Trouble is I obviously now have no background ventilation.

What's the best way around this? I was considering just adding a pair of adjustable 229x76mm wall vents like this, positioned high-wall.

Thoughts?

[Brian_UK]

As you say a couple of vents should help, I would try and include a low level one as well if it can be done without causing a draught.

Is it possible, feasible, to convert the glazing to openers if you didn't want to open the walls up.

[grump]

Hi Double French doors, floor to ceiling glazed wall,12x12
space,is the glazed wall south facing?What is the cooling capacity AC?are you going to keep the doors closed in the summer months?how many persons in the space at any one time?you could fit an auto vent via humidistat control,Fit an extract fan toilet type controlled via occupancy sensor,or an ideal scenario a VAM unit energy recovery keep the carbon footprint to a minimum.Please advise re gazebo warming party.I am assuming all floors walls ceiling have been insulated.
Grump:confused::D:eek:

[Jimbo!]

Thanks for the replies Gentlemen!

I don't want to adapt the windows, as it will spoil the look. I could however add trickle vents on the actual doors. Unfortunately there is not enough clearance on the window.

HRV is obviously an option but expensive even for a cheapo job and will have a running cost for the fan, presumably. Would (say) 30w for the fan be less than the losses through vents?

The large glazed area is north facing, 4.5 sq. m K glass of course, the french doors are east facing and the same area.

Walls are 215mm thermalite + 25mm celotex + p.brd, ceiling is p.brd+ 100mm glass fibre. Workshop end of same construction (minus the windows) and half the volume, achieves 7*C rise with 160w (being produced by a computer!).

AC is Hitachi 2.5kW inverter jobbie. Heating side is really good - day it was working was about 0*C outside nice and warm inside - but it's only just gone in so don't know about cooling yet. No doubt I'm about to be told it's undersized!

I'm not that fussed about cooling to 21*C on the very hottest of days, it's more for energy efficient heating with some cooling as well. System has a COP of 4.3 iirc.

Thanks!

[grump]

Hi Jimbo I am sure you will be very comfortable in your 12 x 12. Grump:D:D:D

[Jimbo!]

really? You think it is sized okay?

[Brian_UK]

Just a quick comment on your "not bothered about 21°C...".

The Japanese instruction books used to, may still?, suggest that the set temperature should only be a few degrees below the outside air temperature.

When you think about it, it does make sense.

[Jimbo!]

Interesting, that mirrors my experience with AC in the home actually. I have a 1920's house, 1000sq.ft, yet with only 5.5kW of cooling it actually stays quite comfortable. The mix of air movement and dehumidification I guess.

[frank]

Just a quick comment on your "not bothered about 21°C...".

The Japanese instruction books used to, may still?, suggest that the set temperature should only be a few degrees below the outside air temperature.

When you think about it, it does make sense.
Any more than a 6k difference between inside and outside temperatures in summer can lead to discomfort through thermal shock.
Hence the design parameters of UK air conditioning:
Indoor 21C
Outdoor 27C