Comments on: A Highrise Hotel Window Head Scratcher

By: Christopher Jones

Christopher Jones — Sun, 22 Sep 2019 15:20:04 +0000

I'm an Architect that worked
I’m an Architect that worked on Prince Edward Island in Canada and now in Kentucky. That vent was marketed by Kawneer, a curtain wall manufacturer, as a way to provide a small amount of ventilation in fixed glazing. Their native habitat is low rise office buildings built a generation after the first energy crisis, and have become mostly extinct with the introduction of “frameless” glass awning windows in storefront and curtain walls. The species is usually found in late 1970s low rise office parks nesting above a wide strip of perimeter fin tube radiation and just below bronze tinted glazing. Usually but not always paired with a energy hogging terminal reheat HVAC system with little to no fresh air supply, The species evolved to provide fresh air after the 1970s reaction to seal every building up but not ventilate and provided a bonus feature for leasing agents for tenants that were beginning to question IAQ. Forgive my delivery. Chris

By: Robin Boyd

Robin Boyd — Sat, 23 Feb 2019 05:59:06 +0000

In reply to Chicken. Chicken, who are you
Chicken, who are you addressing? Your comment and question do not seem to be relevant to this conversation. As to your question, ambient temperature is not the only factor determining when heat pumps begin to frost. A lot more information is needed.

By: Chicken

Chicken — Fri, 22 Feb 2019 03:21:55 +0000

Thanks for telling us what
Thanks for telling us what and how to think. I've been searching the NET for years and am finally fed up with not finding an answer to my question about the wonderful fantastic heat pump. That is, I need to know if mine's normal, so what's a reasonable ambient temp where frost begins to build on the outdoor evaporator? TYVM!

By: Robin Boyd

Robin Boyd — Sun, 27 Jan 2019 21:04:38 +0000

In reply to John Brooks. No doubt about it that being
No doubt about it that being occupant controlled is foolish. Even those of us in the industry forget to properly utilize available ventilation properly. It is always best for ventilation, which is so prone to changes of the environment, be sensor controlled. The changes in the pressures just from being on a higher level of a building is going to dramatically change the needs. At the very least, some sort of barometric control should be incorporated in such a vent.

By: John Brooks

John Brooks — Sun, 27 Jan 2019 18:29:19 +0000

Hi Robin,
Hi Robin,
I pretty much agree with you.
I don’t think the “concept” is foolish.
This particular installation seems foolish depending on the intention.
If the intention was to reduce condensation …
I think it is foolish to make it occupant controlled.
If the intention was “marketing”, it doesn’t seem so foolish.

By: Robin Boyd

Robin Boyd — Sun, 27 Jan 2019 18:05:38 +0000

In reply to John Brooks. John, I must respectfully
John, I must respectfully disagree that the concept is foolish or just a marketing scheme. Just like most concepts, it certainly may be foolish in certain applications, but also may be just as beneficial in others. Just like so many ideas, the production process tends to cause the most issues. In this case it is the material the vent is made of that is causing a thermal bridge that is being exasperated by the ability of cold air to travel past the thermal bridging material. As for smokers being inconsiderate, that is a human flaw that we can never do much about. As I have mentioned, leaving my bathroom window cracked open just a bit, allowing about as much air as that trickle vent allows to pass through, my bathroom is always Spring fresh and condensate free.

By: John Brooks

John Brooks — Sun, 27 Jan 2019 16:14:05 +0000

Some folks are leaning toward
Some folks are leaning toward the theory that the “purpose” of the vent is pressure relief or equalization.
Some folks think the vent is foolish no matter what the intended use.
I think IF the “purpose” is pressure related …. the feature IS foolish.
Foolish because there is no telling what position (open/closed) the vents will be in.
….
What if the “purpose” was a marketing decision?
What if the designer/developer felt that some occupants might appreciate the feature?
Some folks might like a little outside air.
I’m not a smoker, however I can imagine someone addicted to tobacco taking a chance near the vent.
This particular hotel is “Non-smoking”, however, they anticipate that some folks might risk the $250 fine.
Might be nice to open a vent after a smoker has polluted the air.
….
Anyway, I remain very curious about the “purpose” of the foolish vent.

By: Robin Boyd

Robin Boyd — Sat, 26 Jan 2019 02:13:53 +0000

I've seen variations of these
I've seen variations of these vents over the years. They are referred to as "trickle vents" and, ironically, their main purpose is to equalize the air pressure and reduce condensation issues. I have to agree that it is the thermal bridging affect that is the problem with this one. I leave the top of my bathroom window cracked open to allow about the same amount of air into my bathroom as this vent does. My bathroom is always under a slight negative pressure due to ERV usage, so the opening I have in my bathroom does reduce humidity and I have never seen any condensate near the opening.

By: Patrick Harvey

Patrick Harvey — Fri, 25 Jan 2019 18:06:32 +0000

I looked at mini splits.
I looked at mini splits. There are 3 units, one that needs two ACs because it has a separate bedroom. One of them just has a window unit that works great, so I have 3 PTACs and a window unit. I needed both heat and AC, and I bought everything for less than $500. A mini split might not be as efficient as you think if I have to have one large enough to run 3-4 units but most of the time only 1 is used. And the dome walls are pretty flat towards the bottom. We have a window in one of them and we put the PTAC below that because the wall is flat there. You can see the property at https://www.airbnb.com/rooms/24919026

By: RoyC

RoyC — Fri, 25 Jan 2019 15:07:35 +0000

Oxter? I had to Google that
Oxter? I had to Google that one. A Scottish word for an armpit. Learn something everyday. I have to remember that one. This is now my favorite term after cloaca.

I used to live near Whitehouse Texas, where someone built several geodesic dome houses in the 1980’s. I still understand the benefits of that design, but perhaps Allison can cover that in a future column.

As for cooling a geodesic dome, I would consider a split system, ducted or unducted depending on the interior layout. You need a vertical outside wall for a PTAC, and I don’t think you can find one in your golf ball.