OT: Swamp cooler question

[Joerg]

Hey guys,

Thinking about installing a smaller unit, no chance to pipe in a big one
because of the way the house is built. The instructions that come with
units like this are paltry:

http://www.homedepot.com/webapp/wcs...n.endeca.EndecaDataBean@537e385a&ddkey=Search

Essentially just "hang it up, affix plumbing, turn on". Great. Our HW
stores can only order them, you can't look at a unit. I want to place it
on a deck and cut a hole into the wall. Questions:

Can they sit on a wooden deck or _must_ they be hung?

How far does the drain and overflow stuff stick out the bottom? They
don't say, but I assume the unit must be raised for that and depending
on how far I could either use or not use such a unit.

How are they powered? Power cord inside or on the outside part?
Amazingly not one word about that in the installation guide. I thought
this is kind of important ...

 

[GregS]

Hey guys,

Thinking about installing a smaller unit, no chance to pipe in a big one
because of the way the house is built. The instructions that come with
units like this are paltry:

http://www.homedepot.com/webapp/wcs/stores/servlet/ProductDisplay?jspStoreDir=h
dus&catalogId=10053&productId=100143013&navFlow=3&keyword=WCM28&langId=-1&searc
hRedirect=WCM28&storeId=10051&endecaDataBean=com.homedepot.sa.el.wc.integration
.endeca.EndecaDataBean%40537e385a&ddkey=Search

Essentially just "hang it up, affix plumbing, turn on". Great. Our HW
stores can only order them, you can't look at a unit. I want to place it
on a deck and cut a hole into the wall. Questions:

Can they sit on a wooden deck or _must_ they be hung?

How far does the drain and overflow stuff stick out the bottom? They
don't say, but I assume the unit must be raised for that and depending
on how far I could either use or not use such a unit.

How are they powered? Power cord inside or on the outside part?
Amazingly not one word about that in the installation guide. I thought
this is kind of important ...

http://www.coolercenter.com/files/om_wcm28.pdf

 

[GregS]

http://www.coolercenter.com/files/om_wcm28.pdf

I would not mind having one for the outside patio. As good as a mister.
Maybe too much air flow.

greg

 

[GregS]

I would not mind having one for the outside patio. As good as a mister.
Maybe too much air flow.

No, for the price I would just use refridgerated air.

I run my house on a 2.5 ton unit. Compressor and condensor fan only
draw 6 amps at 220. It cheap to run.

greg

 

[GregS]

No, for the price I would just use refridgerated air.

I run my house on a 2.5 ton unit. Compressor and condensor fan only
draw 6 amps at 220. It cheap to run.

Funny that a more efficient systems draws more amps. The tighter
compression is required on the most efficient coolant. Also thicker
metal walls.

greg

 

[Charlie E.]

Hey guys,

Thinking about installing a smaller unit, no chance to pipe in a big one
because of the way the house is built. The instructions that come with
units like this are paltry:

http://www.homedepot.com/webapp/wcs...n.endeca.EndecaDataBean@537e385a&ddkey=Search

Essentially just "hang it up, affix plumbing, turn on". Great. Our HW
stores can only order them, you can't look at a unit. I want to place it
on a deck and cut a hole into the wall. Questions:

Can they sit on a wooden deck or _must_ they be hung?

How far does the drain and overflow stuff stick out the bottom? They
don't say, but I assume the unit must be raised for that and depending
on how far I could either use or not use such a unit.

How are they powered? Power cord inside or on the outside part?
Amazingly not one word about that in the installation guide. I thought
this is kind of important ...

Hi Joerg,
Looking at the parts list, I 'think' the cord goes inside, and the
plumbing outside. I would probably allow at least six inches to reach
under the unit to get to that drain area. I think I would put a hose
on it, and run the flow out either below or beyond my deck. Maybe
make a redwood frame to support it...

Charlie

 

[Joerg]

http://www.coolercenter.com/files/om_wcm28.pdf

That's what I have. Not much info in there.

 

[Joerg]

Funny that a more efficient systems draws more amps. The tighter
compression is required on the most efficient coolant. Also thicker
metal walls.

Well, our central A/C pulls in a whopping 7kW. Once your (smallish)
monthly baseline limit is used up the cost per kWh can double and
triple. In summer they really sock it to people. I knew a rather
heat-sensitive elderly lady who regularly paid $1000/month.

 

[Joerg]

Hi Joerg,
Looking at the parts list, I 'think' the cord goes inside, and the
plumbing outside. I would probably allow at least six inches to reach
under the unit to get to that drain area. I think I would put a hose
on it, and run the flow out either below or beyond my deck. Maybe
make a redwood frame to support it...

6" will be tight. There's probably a beam underneath the window that I
am not s'posed to cut into. Which I will only know after breaking into
the wall.

What does one do in winter? The usual canvas cover doesn't sound like a
great insulator.

 

[Joerg]

Hi,

I have a large rooftop swamp cooler for my home.

For a side-discharge window unit I recommend using a wooden platform
or other support structure (e.g. wall anchored metal bracket). The
water drain hole must be left accessible, but it does not protrude
more than ~1 centimeter below the bottom surface.

Thanks! Then I could raise it only a couple of inches and plumb in an
elbow for drain and overflow, connect both below the deck so the drain
shutoff could be there, and run a common PVC drain pipe from there. Or
drill two holes and go through the deck.

These units usually have a separate electrical outlet box inside the
cooler with outlets for both the motor and the pump. The motor will
have its own specialized plug while the pump will have a standard 120V
or 240V plug depending on your model. This electrical box inside the
cooler should be wired to the common AC cord (for 120 or 240 V
depending on what you bought), and the cord will be plugged into an
outlet close to the inlet window vent, inside the house. Beware -- if
you buy a 240V unit, then the wall outlet near the window must support
240V.

This would be 120V. But we couldn't run the vacuum cleaner while this
thing is running. It draws 4-5 amps off of 120V.

A small diameter water line (plastic or copper -- I use plastic) must
be plumbed from the fitting on the cooler to a water source. The
instructions GregS linked-to explains this in detail.

Yeah, that's easy (but a long run). I'd use 1/4" copper because it's
nice and pliable.

The power difference between a window-discharge swamp cooler and a
window-mounted refrigerated air conditioner is not that significant.
For my whole house the difference *is* significant. I would need
about 6 - 7 Tons of A/C for my house, which could draw in excess of
30A (120V), while my swamp cooler only uses slightly more than 5A
(120V).

I want to use it for the whole house. Realizing that it won't do the
upper 2500sqft, the offices don't need much cooling. I'd just let the
air back out there. If it cools the living room and open kitchen that's
plenty for us.

Don't know the tonnage of our A/C off the top of my head but I know it
draws 7kW, or around 240V/30A. So we set it to 85F, and only because our
old Rottweiler can't take the heat anymore. I assume this little swamp
cooler might do better than 85F if it's 100F outside, or at least match it.

 

[Artemus]

Hey guys,

Thinking about installing a smaller unit, no chance to pipe in a big one
because of the way the house is built. The instructions that come with
units like this are paltry:

http://www.homedepot.com/webapp/wcs...n.endeca.EndecaDataBean@537e385a&ddkey=Search

Essentially just "hang it up, affix plumbing, turn on". Great. Our HW
stores can only order them, you can't look at a unit. I want to place it
on a deck and cut a hole into the wall. Questions:

Can they sit on a wooden deck or _must_ they be hung?

How far does the drain and overflow stuff stick out the bottom? They
don't say, but I assume the unit must be raised for that and depending
on how far I could either use or not use such a unit.

How are they powered? Power cord inside or on the outside part?
Amazingly not one word about that in the installation guide. I thought
this is kind of important ...

My comments are based on living with swamp coolers in Arizona
for 40+ years.

Yes it can sit on a deck, or concrete blocks, a wood or metal frame,
etc. It is not necessary to provide 100% support under it, a frame of
2x4's around the outside edge of the base is adequate.

The drain fitting sticks out the bottom less than 1" and is threaded for
a garden hose. When installed the garden hose will stick straight down.
You can install an elbow for tight installations. The overflow is entirely
inside the cooler box. No drain shutoff is necessary. PVC pipe is ok
for the drain line.

Installing a bleed off kit will extend the life of your pads and greatly
reduce the calcium build up the metal parts.
http://www.idealtruevalue.com/servlet/the-47672/Detail

The unit you linked to will have 1 external electric cord with a standard
plug. All other wiring will be factory installed inside the unit.

For winterizing: unplug the electrical, drain the water and wrap it with
a tarp. If you have freezing temperatures you will need to purge the
feed water tubing too. Insulation is usually done by covering the inside
part with a cover of ones own making.
Art

 

[Joerg]

You might need to make a trip to AZ to avoid a Californicated unit

They come side-draft or down-draft. You probably should get a
side-draft body to make your duct-work easier.

Looked at it. Those are way larger and the only place I can reasonably
put it is on the north side of the deck. That's where the deck is only
5ft deep and the typical large side-draft unit would cause a permanent
road block

The WCM28 is the only one that might fit.

 

[Joerg]

My comments are based on living with swamp coolers in Arizona
for 40+ years.

Yes it can sit on a deck, or concrete blocks, a wood or metal frame,
etc. It is not necessary to provide 100% support under it, a frame of
2x4's around the outside edge of the base is adequate.

Good, thanks!

The drain fitting sticks out the bottom less than 1" and is threaded for
a garden hose. When installed the garden hose will stick straight down.
You can install an elbow for tight installations. The overflow is entirely
inside the cooler box. No drain shutoff is necessary. PVC pipe is ok
for the drain line.

Technically the overflow should never come on anyhow so if that oozes
it's probably ok.

Installing a bleed off kit will extend the life of your pads and greatly
reduce the calcium build up the metal parts.
http://www.idealtruevalue.com/servlet/the-47672/Detail

I think they should be bled weekly to avoid that "indoor swimming pool"
smell. Maybe I just use the drain for that.

The unit you linked to will have 1 external electric cord with a standard
plug. All other wiring will be factory installed inside the unit.

Darn. There ain't no outlet on the outside, and not easy to run power there.

For winterizing: unplug the electrical, drain the water and wrap it with
a tarp. If you have freezing temperatures you will need to purge the
feed water tubing too. Insulation is usually done by covering the inside
part with a cover of ones own making.

That part will require some custom fitting anyhow. Seems they made the
tunnel one piece, with flanges. That's unfortunate because I'll have to
make the hole larger than it needs to be. Meaning a frame on both sides
and then the inner one can hold a homemade wood cover with an acceptable
WAF. Stained to match furniture, maybe.

 

[Artemus]

Good, thanks!



Technically the overflow should never come on anyhow so if that oozes
it's probably ok.

The overflow is nothing more than a thinwalled PVC tube about 3-4" long
stuck in the drain fitting on the inside of the unit. If the water level gets
higher than the end of the tube it simply drains out. No moving parts.
Remove the tube to drain all the water out.

I think they should be bled weekly to avoid that "indoor swimming pool"
smell. Maybe I just use the drain for that.

Draining will not help that.
The swamp smell is due to algae growth on the pads. New pads are
treated to prevent this but the treatment doesn't last forever. Growth
usually only happens with round the clock operation in higher outside
humidity. This allows algae to grow on the pads. In low humidity, low
teens and less, I've never seen algae growth. Turning the unit off and
allowing the pads to completly dry once a day will also inhibit algae
growth.

BTW. The aspen fiber pads are the best IMHO. They smell
wonderful for the first couple of days and provide the best temperature
drop. Paper ones are a so-so second choice. Plastic ones suck.

Darn. There ain't no outlet on the outside, and not easy to run power there.

No problem. Pull the cord back inside the unit, drill a hole in the sheet
metal duct next to the outside edge of the box, install a grommet, and run
the cord through. The cord can them be run out the louvers inside the
house, or through another hole drilled in the side/bottom of the duct.

 

[Joerg]

The overflow is nothing more than a thinwalled PVC tube about 3-4" long
stuck in the drain fitting on the inside of the unit. If the water level gets
higher than the end of the tube it simply drains out. No moving parts.
Remove the tube to drain all the water out.

So you have to take a panel off every week? I think I am going to modify
that

Draining will not help that.
The swamp smell is due to algae growth on the pads. New pads are
treated to prevent this but the treatment doesn't last forever. Growth
usually only happens with round the clock operation in higher outside
humidity. This allows algae to grow on the pads. In low humidity, low
teens and less, I've never seen algae growth. Turning the unit off and
allowing the pads to completly dry once a day will also inhibit algae
growth.

Right now the humidity is 25%, temperature is around 100F. At night we
sometimes have high humidity rolling in from the coast. It's 100 miles
away but one never knows on which days this delta breeze will roll in.

BTW. The aspen fiber pads are the best IMHO. They smell
wonderful for the first couple of days and provide the best temperature
drop. Paper ones are a so-so second choice. Plastic ones suck.

Yes, that's what I heard and read. Many Australians seem to prefer the
cardboard kind for some reason.

No problem. Pull the cord back inside the unit, drill a hole in the sheet
metal duct next to the outside edge of the box, install a grommet, and run
the cord through. The cord can them be run out the louvers inside the
house, or through another hole drilled in the side/bottom of the duct.

Well, if that's legal and would pass a home inspection some day it
should be no problem.

[...]

 

[Artemus]

So you have to take a panel off every week? I think I am going to modify
that

There's really no need to 100% drain it on a weekly basis. But yes, you
will have to pull a panel to drain it. Pulling a panel is simple as it is held in
by gravity and all you have to do is lift it up and out. Just don't plug or put
a shut off in the drain line or the cooler pan will overflow in the event of a
stuck float valve.

Right now the humidity is 25%, temperature is around 100F. At night we
sometimes have high humidity rolling in from the coast. It's 100 miles
away but one never knows on which days this delta breeze will roll in.

I have a chart somewhere showing the temp differential a swamp box
can deliver depending on the outside air temp & humidity but I can't find
it right now. When I find it I'll post it.

Yes, that's what I heard and read. Many Australians seem to prefer the
cardboard kind for some reason.

Unavailability of aspen ones down under?

It would be good idea to have spare pads on hand for a mid season change.
In AZ they were plentiful and cheap in April-May but rare and cost more
later on.

Art

 

[[email protected]]

No, for the price I would just use refridgerated air.

I run my house on a 2.5 ton unit. Compressor and condensor fan only
draw 6 amps at 220. It cheap to run.

Something's not right with these numbers. 2.5T = 30kBTU/Hr = 6.5kW. You're
claiming 15kW (assuming perfect efficiency and unity PF), so that's a pumping
"efficiency" of the entire system, from electricity (in VA, no less) to heat
pumped of greater than 4.3. Looking at it another way, that's a SEER of 21,
again assuming a PF of unity and no heat generated (excluding pumped heat).

 

[Artemus]

I have a chart somewhere showing the temp differential a swamp box
can deliver depending on the outside air temp & humidity but I can't find
it right now. When I find it I'll post it.

View in fixed font
Outside air temp in left column
Relative Humidity
2% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
75 -21 -20 -18 -17 -16 -14 -13 -12 -11 -10 -9
80 -23 -22 -20 -18 -17 -16 -14 -13 -12 -11 -9
85 -24 -23 -22 -20 -18 -17 -15 -14 -13 -12 -11
90 -26 -25 -23 -21 -20 -18 -16 -14 -13 -12 -11
95 -28 -27 -25 -23 -19 -17 -16 -16 -14 -13 -11
100 -31 -29 -27 -24 -21 -20 -18 -17 -15 -13 -12
105 -33 -31 -28 -26 -24 -21 -19 -17 -16
110 -35 -33 -30 -27 -25 -23 -20 -18
115 -37 -35 -32 -29 -26 -24 -21
120 -39 -37 -34 -30 -27 -25

At 100 degress and 30% you can expect the cooler to deliver 82 degree
air into the house. The humidity of that air is going to be much higher than
30%.

Art

 

[Joerg]

View in fixed font
Outside air temp in left column
Relative Humidity
2% 5% 10% 15% 20% 25% 30% 35% 40% 45% 50%
75 -21 -20 -18 -17 -16 -14 -13 -12 -11 -10 -9
80 -23 -22 -20 -18 -17 -16 -14 -13 -12 -11 -9
85 -24 -23 -22 -20 -18 -17 -15 -14 -13 -12 -11
90 -26 -25 -23 -21 -20 -18 -16 -14 -13 -12 -11
95 -28 -27 -25 -23 -19 -17 -16 -16 -14 -13 -11
100 -31 -29 -27 -24 -21 -20 -18 -17 -15 -13 -12
105 -33 -31 -28 -26 -24 -21 -19 -17 -16
110 -35 -33 -30 -27 -25 -23 -20 -18
115 -37 -35 -32 -29 -26 -24 -21
120 -39 -37 -34 -30 -27 -25

At 100 degress and 30% you can expect the cooler to deliver 82 degree
air into the house. The humidity of that air is going to be much higher than
30%.

Thanks, Art! I have no good data for the average humidity out here but
Sacramento about 35mi west in the valley is supposedly 30% average in
summer. We are about 100ft high so (hopefully) less humidity.

Even if we'd only get it to 82F that's better than 85F using a 7kW A/C.

As for the pads, we tend to buy stuff like that off season and store it.
Just like we buy our firewood in March or April.

 

[Joerg]

Huh? 82°F at very high humidity is horrible.

I know, that's why I am not totally sold yet on swamp coolers. But the
propane company technician who was here this morning said his swamp
cooler works great.

At your place how much electricity do you use to get 85°F
air-conditioned.

There are only 6-8 days a month where we have to do that, mostly because
old Rottie needs it. When it's 100F outside this unit will eat 7kW and
run somewhat above 50% duty cycle. Since most such days aren't followed
by a delta breeze and it doesn't cool off at night you'd be looking at
well north of 50kWh/day (duty cycle goes down in the evenings).

IF you can find Aspen pads off-season. They're cheap BTW.

Yeah, I am not worried about those. I am more concerned about things
like the large slots and holes and no screen on those machines. Perfect
invitation for critters to come in. It looks like at least up to the
size of mice could fit through. And out here, when they fit they'll
come. Somehow the designs look dated and incomplete.