Blinds

Brooksie said:

I agree with you, I think once the sunlight is through the glass, most of the heat is already in the boat/house....... Inside, some heat is reflected back but most, I think, wafts up between the blind & the glass.

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There's an engineer in my marina who has done significant testing on the problem. (Recording thermometers and the like.) His conclusions mirror what Brooksie just posted.

I must say that I do like the Hunter-Douglas knockoffs that some others have posted.

dannc said:

The blinds will work better if they are IN the window casement. That certainly is not going to happen on all/many boat windows.

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I agree and have Pella windows in my house. The windows and doors have 3 panes of glass....double glass (e-glass and thermal) and a pane that houses the blinds. (No dusting necessary) The interior pane is hinged and does open for cleaning by the occasional resident who suffers fro OCD. IMO, however, it is not needed. (The cleaning, that is!)

For heat reduction, we use the belt and suspenders approach. We snap on our sunscreens to the outside of the windows and drop the blinds on the inside. It limits the amount of sunlight/heat hitting the glass on the outside and reflects/blocks from the inside. Add a bit of air moving through the cabin from fans or our breeze booster hatch scoop and it's nearly comfortable.

Next month I'll break out my bucket swamp cooler I put together last fall. I haven't used it on the boat yet, but the dry summer heat of the CA Delta should be the perfect place to try it out. Last year in my hot garage, it cooled the 95*F air by about 20*F.

Welcome to the redneck Yacht Club!!

Marin said:

Blinds work to reduce interior heat on boats for the exact same reason those collapsible windshield shades work inside the windshields of vehicles. Anything that's reflects the sun back out reduces the heat inside.

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That is a very good comparison. I have used sun shields for years in my cars and the best sun shiel is the current one that has a shinny, reflective foil that reflects the sun light. When there is no threat of rain, I crack the windows to allow the heat to escape which also helps greatly. The heat buildup of the interior makes the AC work harder so any way to decrease the interior mass from heating up is a good thing.

In our passive solar house, we want that heat build up in the winter but not the summer. The roof overhangs prevent the summer sun from getting in the house except of the west side of the house. We have a carpet on the floor to minimize heat build up but the house is much hotter because of sunlight entering the house from the windows in two French doors.

I wonder....

Would the wife allow me to fit reflective foil to the windows in question?



Later,
Dan

I have blinds mounted inside on my boat. I have a lot of glass and the blinds make a large difference in temps inside. The blinds fold up nicely while underway.

Love our Hunter Douglas shades. We also just upgraded our old, sunburned, black Phifertex mesh windshield cover with a new Phifertex Plus black cover. The heat transfer difference is tremendous - even though the cover is still black. The "Plus" has a 90-95% shade factor, as opposed to regular Phifertex with its 70% shade factor. In fact, we liked it so much that we had velcro-on Phifertex Plus white covers made for the west-facing side of the aft deck enclosure. Here in South Florida, everyday from May through September, our back deck was unusable in the late afternoon - even with the AC cranked up out there it was way too hot to sit. With the new mesh - in spite of the fact that it is on the INSIDE of the isinglas, we can keep the temp down to the low 80s all afternoon and evening. Looks great too, I think!

I am considering doing something like this...but putting them on the outside of the window. In agreement with Codger regarding heat. It needs to be outside of the boat to really affect heat in boat.

Codger2 said:

I guess I'm going to be the "doubting Thomas" in this thread but, for the life of me, I don't see how blinds inside the boat keep the heat out! I know they keep the sun light at bay & provide privacy but since the blinds are in the boat, isn't the heat already in the boat when the sun comes through the windows? I have blinds on my boat but when I hold my hand up to them on a sunny day, I can still feel significant heat. Low E-glass or tinted windows seem to be a better solution to the problem. My windshield is covered by Sunbrella and my salon sliding doors are tinted. Even with direct sun on the sliding doors, not much heat can be felt.

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We have tinted front and side windows, and inside mini-blinds along the saloon sides. When the blinds are closed on the "sunny side of the boat" I can easily feel a noticeable difference in temps a) just inside the blinds, and even more b) in between blinds and window glass.

Ambient temps throughout the saloon are noticeably lower than temps just inside the blinds.

-Chris