Air Quality of Air Pumped to Ponds

[Dale Torok]

Reading some comments by Dick Benbow on another forum has caused me to have some concern about what could possibly be a similar situation in my pond. Dick repeated a story he knew of a Japanese breeder who lost a pond full of nisai as the result of having an air pump located in an enclosed filter building pumping air into the pond. Dick's words at the conclusion of the story....."Something had gotten into the building and it was pumped into the pond resulting in a total wipe out."

I now have a question for the koi keepers who read this forum for advice and to advise others. I lurk more than participate on Koi Bito, but read everything that is posted here. So, please let me thank the posters here. I enjoy and learn from your experience. Dick's story has prompted my first 'new' post on Koi Bito with my concerns about air being pumped into the pond.

I built a building to house my filtration equipment last year. I wanted to have the room with the filters heated and ran a natural gas line to the building. I installed a ventless gas heater to heat the building. These type of heater is called a 'Blue Flame Ventless Gas Heater' The brand name is 'Comfort Glow', but there are several others on the market. Before installing this gas heater, I was concerned enough about it being vent free that I called the technical assistance department of the manufacturer about it with questions about the carbon dioxide or carbon monoxide that would be generated from the gas burning and also the oxygen level in the air. I was told that these heaters burn so efficiently that oxygen depletion is not a problem to worry about.

Even so, the manufacturer has as an added precaution incorporated an oxygen sensor in the heater. The sensor will turn off the gas to the unit if it senses oxygen levels below whatever the national standards are for indoor air.

Does anyone here have any experience or knowledge of the use of these ventless gas heaters in a filter building where air pumps are located? Is anyone else using one in a filter building or room?

I ask because I have 2 bottom drains in the koi pond that flow to 2 Nexus units. Two air pumps are pumping air into the outer chambers of the filters to aerate and tumble the kaldnes media. Of course, the air the pumps are pumping is the heated air in the filter building. I also have a large air pump pumping air to the two bottom drains with air domes. This warm air does exchange some heat to the water in the pond. The pond is covered with 6 mil plastic, so as the air rises, I'm sure it is keeping the air over the pond, under the cover, as a warm blanket.

This is my way of 'heating' the pond this winter. Not necessarily heating it, but it is really helping. We have had single digit temperatures at night and only up into the low 20's for over 2 weeks now and the water temperature is holding at around 46 to 47 degreed Farenheight.

The gas heater is thermostatically controlled. I am keeping the heat in the fiter building at about 55 degrees F. I am very pleased that the warm air surrounding the 2 filters and the warm air being pumped into the water is holding the temperature up as well as it is. My concern is the ventless gas heater and the air quality of the air that is being pumped into the water by 3 different air pumps. I don't notice any difference in the air quality when I walk into the filter area and have no problem breathing it. I have an underwater camera and can observe the fish under the winter cover. I don't see anything out of the ordinary.

Any comments from others would be appreciated, especially if you are or know of anyone using one of these ventless gas heaters in their filter rooms or buildings. These heaters are very popular. They are sold at Lowe's and Home Depot and in use in many homes. Maybe I'm worrying about nothing, but you never know.

FYI, here is a link to the manufacturer's website containing information about the emissions by the gas heater:

http://www.fmconline.net/charts/vf-heat-right.html

You can click on the 'Home' link at the bottom of this page to see the ventless heaters.


The statement below is copied from their website:

Let's Clear the Air" Regarding the Effect of Vent-Free Gas Heaters on Indoor Air Quality In 1995, the scientist at the American Gas Association's Research Division (AGAR) tested the levels of all five major contributors of indoor air quality - oxygen, carbon monoxide, carbon dioxide, nitrogen dioxide and water vapor (humidity) - against the latest Indoor Air Quality (IAQ) guidelines and concluded that vent-free gas heating products performed well within nationally recognized guidelines for indoor air quality.
This research proves that vent-free gas heating products meets applicable emissions requirements, even when used over extended time periods, among sensitive populations, and even with oversized units.


Dale Torok

[aquitori]

I read that in the "other magazine" not to long ago...I think we have to keep in mind is that the air pump we use is to pump the surrounding air around it into the pond...If the air pump is around something that emits dangerous fumes 100% of the time those fumes will be pumped in the pond. So, unless you have the budge to pump pure oxygen into the pond I suggest finding a place that is safe and open to fresh out door air...

[MikeM]

The information provided at that website is rather too general for my liking. However, since this technology is getting rate as safe for human habitation, it is very likely fine for your use. I note that some venting is suggested for homes with very "tight" construction. I suspect your filter house is not as air tight as the latest energy-efficient home designs. There is probably some leakage around the door and window (assuming you have one?). If you were really careful to build it "tight", then you may need to crack the window a hair to allow some outside air seepage. Since no problems to date, I'd not worry too much. But, I think you are right to stay alert to any change in koi behavior.



About 7 years ago my wife & daughter painted a bedroom at the opposite end of the house from where I keep aquaria. It was a latex paint with very little odor. It was a warm season and the air conditioning was on. Within 24 hours every guppy in the aquaria was dead. All other fish seemed O.K. Fumes from the paint were the suspected culprit, although it could hardly be smelled at that end of the house. No air pumps are used on any of the aquaria. Aeration is accomplished through water movement and wet/dry trickle filters maximizing exposure to the atmosphere. So, I learned the hard way.

[Dale Torok]

Thank you Aquitori & Mike,

I've been keeping a close watch on the fish since reading Dick's post & haven't yet seen anything that looks like a problem. When I read Dick Benbow's story about the air pump transferring something from the filter building to the pond, I started wondering what it could be. I suppose it could have been fumes from an evaporating solvent or paint, but he didn't say. I do know that an unvented gas water heater in a basement can asphyxiate people in the house, so I started wondering about the gas flames in my 'ventless' heater and the level of oxygen in the air. Also, I recall reading stories in the newspaper about people dying from using kerosene heaters in a closed up room or building. However, I don't think keroses heaters are very clean burning and would probably burn up a LOT of oxygen.

The filter building does have windows and doors and I'm sure they aren't completely air tight, so that must be enough to keep things OK in there. I really don't want to set the air pumps outside because right now, they would be pumping about 20 degree fahrenheit air in the water! It's darn cold here. Too cold in Kentucky for December. We don't usually see winter weather this cold until January.

Dale

[B.Scott]

Ok Dale, As a heating and plumbing person you are walking down my street now.

First off... there is no such thing as a ventless gas heater. The only difference is the gas goes into the room and then disapates via the ventalation instead of leaving via a pipe. As long as the room is large enough and has adequate ventilation there is no real problem. However, as the O2 levels begin to fall the reaction producing CO2 starts producing an ever larger amount of CO ie carbon monoxide. Carbon monoxide binds with hemaglobin 100X faster than oxygen. The trouble is it isn't metabilized and just sits there in the blood cell taking up space. When enough blood cells are carring CO then you become anemic and if it continues you die of oxygen starvation. It's about par to having you blood replaced with salt water.
As for the O2 sensor, most systems relay on the behavior of the combustion flame to indicate to lack of O2. This will allow a minor buildup of CO before it cuts off the combustion bed. In any case having the airpump located in the same space with mean the possible difussion of other (possibly harmfull) bi-products of combustion into the water of the pond.
The other down side to these heaters is the tremendous amount of water condensation they produce. We aren't talking "a little moisture" here but rather "Dripping walls" when one of these puppies is going full blast.
The sad thing is these guys are cheap and require no real installation. This tends to tempt people to think they are OK. In a tent, on a patio, in a large drafty space these heaters are ideal. But believe me me I wouldn't want one in my bedroom unless the only alternative was freezing to death.
I don't think it wise to use these in your koi filter house Dale. Even with enough air you are still putting by-products of combustion into the pond.
I do know of an alternitive. I don't know if you have them where you are, but we have some small, wall mounted heaters here the have the intake and out-let in the same pipe, The only thing to get inside is the heat. Perhaps an option?

B.Scott

[MikeM]

Dale: Winter in Kentucky ... lots of good memories of snow days growing up in Louisville. Also not so fond memories of riding my bike to school on icy streets and gray, overcast skies, drizzly cold rain, and getting tired of indoor games. Down the block was an elderly couple who had a goldfish pond in their backyard. The pond would freeze over, but "pardner" [the old man's nickname among us kids] would float a chunk of wood in the winter. He told me that was his secret for keeping the goldfish alive for years, that the wood let the fish breathe when the pond froze. Did not make sense to me then, but I think it "vented" the pondwater in a low tech sort of way.


Happy wintertime. I'll think about your 20F air temps as I gripe about our 45F nights.... been a chilly December for central Florida.

[dick benbow]

Dale, thanks for your post here. Your presence is welcome.

[swordfish]

Fresh air to human is fresh oxygen to koi too.

SF

[Dale Torok]

Quote: Originally Posted by MikeM Dale: Winter in Kentucky ... lots of good memories of snow days growing up in Louisville. Also not so fond memories of riding my bike to school on icy streets and gray, overcast skies, drizzly cold rain, and getting tired of indoor games. Down the block was an elderly couple who had a goldfish pond in their backyard. The pond would freeze over, but "pardner" [the old man's nickname among us kids] would float a chunk of wood in the winter. He told me that was his secret for keeping the goldfish alive for years, that the wood let the fish breathe when the pond froze. Did not make sense to me then, but I think it "vented" the pondwater in a low tech sort of way. Happy wintertime. I'll think about your 20F air temps as I gripe about our 45F nights.... been a chilly December for central Florida.

Hi Mike,

It's easy for you to say "Happy wintertime" from where you are....... Bah, humbug to you snow birds in Florida. Sounds to me like you are a permanent one down there.

You certainly wouldn't want to be back in Kentucky today. I ventured out before daylight this morning to go to my weekly Rotary Club meeting. Our club meets for breakfast on Tuesday mornings at 7:00 am. It was 20 degrees F with a wind chill of 13 F. So darn cold that our scheduled speaker didn't even show up! And only about a dozen of our Rotary members were there.

Based on B. Scott's comments above, I inspected the filter room for moisture. The walls are dry. A double insulated glass wall separates the half of the building where the filters are located & there is no moisture buildup on them. The 2 outside windows to this half of the building do have moisture beaded up on them, but moisture isn't on 100% of the glass. I also have moisture on many windows in our home, so I'm thinking this isn't cause for alarm. The fish seem fine this morning. There are air spaces under the doors to the filter area for ventulation. I insulated the building so well that the gas heater isn't running very much to keep the temperature in the low 50's in there.

I've never posted a picture here, but will attempt to post one I took from the upper level of the building toward the filter area. Of course, this picture was taken a few weeks ago before winter arrived.

Dale

[MikeM]

Whoa! ...."House Beautiful" version of a filter room! I am impressed. Every sign of a very careful person attentive to detail.