Any experience with radiant heat?

[StoneHeartFarm]

Bird,

The Evaporative coolers are so rare here that I've never even seen one, and have no idea how you could tell the difference between a regular unit and an evaporative unit. About the only time we need humidifiers is in the winter when the furnace dries the air out.

SHF

 

[Bird]

SHF, at the City of Phoenix site http://www.ci.phoenix.az.us/WATER/evapcool.html#TOP you can see a pretty good diagram of how they work. The big difference is that the one they show is for a roof mounted unit with the air discharge directed down and I grew up with window units with the air discharge (from a squirrel cage blower) out the side. There at least used to be some small portables made; I used to have one that was less than 2' square and had a water reservoir you had to keep filled instead of being hooked up to a water hydrant. And they even made some small window mounted units for cars and trucks.

Bird

 

[Anonymous Poster]

This may seem a dumb idea, but after goin thru the heat wave here, I been thinking of installing a small pump to "irrigate" my roof. My thinking is that the water running down the roof will evaporate off, thereby cooling the roof, and keeping the attic cooler in the process. That ought to minimize the reradiation of infrared from the ceilings, and cut the need for mechanical cooling in the house.
Seemed like it might just work after watching the vapor coming up from the roof after one of our 10 minute rain showers.

 

[Bird]

Franz, I don't think it's a dumb idea at all, but have some doubts about its cost effectiveness; just don't know. You know the "experts" recommend the outside portion of your refrigerated air-conditioner (compressor, condenser, etc.) be located in as much shade as possible, and where it can get free air circulation; however, many of them are actually located where they get full sunlight all day. Several years ago, I saw something advertised that was a sprinkler system to spray a fine mist of water on the condenser coils; seemed like a good idea to me, but I've never seen one in use and haven't even heard of such in a lot of years.

Bird

 

[patrickg]

Bird, A few years ago(2-3) I had a team of 30 people co-located in an old corrugated metal bld (temp bld, just for duration of the war (WW-II) It didn't have particularly great thermal characteristics and everyone on the team had at least one PC and monitor (artists had multiple monitors and some tech weenies had multiple PC's). Anyway 30 bodies and 35 PC's made a lot of heat and the sun does shine in San Diego, even down at the bay a few yards from the water. The vagaries of Government regulations (This was a DoD/Navy lab, SPAWAR - Space and Naval Warfare Systems Engineering Command) from various levels prevented central air in the bld. I took my Government credit card to Sears where America shops and bought two of the largest window A/C units they sell. They were 208/220 volt units. With the help of one volunteer I installed them in holes cut out in the side of the bld. Jackhammered holes in the parking lot and put in pedestals to support the weight so the vibration/noise wouldn't be transfered to the metal shell of the bld. Used old disk brake rotors off my wifes Mercedes to spread the load between metal shelf and vertical support pipe set in quick setting cement. Did it all on a weekend except for having a "Real" electrician run the wiring (I'm brave but not entirely stupid when it comes to unauthorized modifications of Government buildings) Having endured this preamble, I hope you aren't too dissapointed by the meager payoff. Anyway the condensor coils (the ones that get hot), as is the usual case, had a fan blowing on them to shed heat to the outside environment. Condensate from the evaporator coils flowed to a pan under the condensor's fan. This fan was a very high aspect ratio plastic three blade fan with a circle of plastic connecting the blade tips. This circle and the blade tips stuck down past the top of the condensate pan. So, when there was a high latent heat load (lots of condensate being formed) the pan would fill with water and the fan would pick it up, break it up into a spray, and sling it into the condensor coils. If you stood behind the unit you could not detect any water coming out with the hot air from the condensor. Pretty clever engineering! When the unit was working the hardest and struggling the most to get rid of heat in the condensor coils it had the most condensate to sling into the condensor to cool it. A fringe benefit was virtually never ever a time when condensate ran out the back. Nearly everyone had been complaining about the heat as summer came upon us. After the install only half of the folks complained about the temp. the women complained it was too cold if the men set the thermostat and the men complained it was too hot if the women set it. If you really turned it up you could have hung beef in there, even with 30 bodies and 35 computers.

Warning: In the above example the water used to cool the condensor coil was condensate, i.e. distilled water (pulled from the room air). Spraying tap water onto a condensor to increase efficiency could be a really bad idea unless your water source is a rain water catchment/sistern or is quite soft (low disolved mineral content). Otherwise, over time (depending on your waters hardness) you will develop a layer of mineralization on your condensor coils and associated fins. This will act as thermal insulation and inhibit its function. It will also begin to plug up the airflow, another bad thing. If you have plenty of water to spare, you could really flood the condensor with a lot of water. This will slow the mineralization but not stop it. If you want to follow this "more water" solution to its logical conclusion, get a freon to water heat exchanger and replace your freon to air heat exchanger(condensor). Now at least during the cooling season you could have free DHW (domestic hot water).

Patrick

Patrick

 

[patrickg]

Evaporative coolers are still in stock and for sale in various H/W and builder supply stores in central/south central OK. I don't know why, as there isn't much heat with low humidity to combat around here.

Patrick

 

[patrickg]

SHF, I don't recall any names off the top of my head but using a search engine, I typed in this search argument:

"heat" + "recovery" + "ventilator" to look for sources with all three words in them but not limited to just
"heat recovery ventilator" in that order with one space between the words. This is what I got. Different search engines might produce different results. Your mileage may vary.

1.The RecoupAerator from Stirling Technology - the solution for Indoor Air Quality - The
RecoupAerator, manufactured by Stirling Technology, is a heat and energy recovery ventilator that
brings fresh air into homes and buildings, both saving energy and exhausting common pollutants suc
http://www.recoupaerator.com/

2.Campeau Heating - Lennox - Heat Recovery Ventilator - The Lennox heat Recovery Ventilator is
a compact electrically-powered unit that circulates air through the entire house, using the existing
forced-air system or specially installed ducts. The unit o
http://cybersudbury.com/business/campeau_heating/lennox/hrv.html

3.Heat Recovery Ventilators (aka Air to Air Heat Exchangers) - Heat Recovery Ventilators New
homes, additions and even remodeling projects are built far more airtight than they used to be.
Building a tight home to today's standards can cut the overall heat loss b
http://energyoutlet.com/res/hrv

4.EREC Brief: Energy Recovery Ventilation for Residences - Energy Recovery Ventilation for Residences The current
trend toward sealing (tightening) houses to reduce air and moisture infiltration makes them more energy-efficient and
less costly to own. Howeve
http://www.eren.doe.gov/consumerinfo/refbriefs/ea5.html

This last ref is a good info source.

Patrick

 

[Bird]

Patrick, I've noticed recently that our local hardware store has some of the evaporative coolers (big window unit models) sitting on the sidewalk in front of the store. And my brother-in-law just left and he mentioned that he's been running a sprinkler on his air-conditioner condenser a couple of hours a day in the heat of the afternoon.

Bird

 

[StoneHeartFarm]

Patrickg

Thanks for the heads up. I just couldn't figure out how to search without wading through a mile of unwanted stuff. Last time I tried for polaris boilers, I got something like 50,000 returns on submarines /w3tcompact/icons/crazy.gif.

SHF

 

[patrickg]

SHF, Glad I could help. Just shine the bat signal anytime. To really make your time spent searching much more productive you would want to learn a bit about (now don't get put off by strange jargon) boolean operators and other "advanced" (yeah advanced!, some grade schoolers use this stuff) search techniques/methods.

"garbage" + "stuff" will only find refs containing both the words, garbage and stuff, in either order.
Where "garbage stuff" looks for the occurance of both words separated by a single space in the order given.

This sort of thing goes on and on and I won't waste bandwidth here making a flawed recitation when there are lots of ways to get the dope on the net. Go to Lycos and click on "Search Tips" and you'll see how easy it is to search for info on Polaris and Boilers but not submarines. I do so little "sophisticated" searching that I take a peek at "the rules" now and again to get it right. Many characteristics are shared between search engines but occasionaly you find a feature not suported on one that another has. Standardization isn't standardized!

Good searching!

Patrick