DIY Mosquito Screens

28 June 2013

Introduction 

Dengue is the  name of a disease spread by a special mosquito called aedes mosquito. 

To date,   It has claimed 4 lives in Singapore.  It is also a common disease in Philippines,  Malaysia and other countries in South East Asia.  So far,  there is no cure or drugs for treating dengue;  doctors will just prescribe pain killers and make observation for life threatening signs. This article will describe the experience that the author has had fighting against Dengue.

How To Prevent? 

The only way is to avoid a mosquito bite but it is easily said than done as mosquito is everywhere.  The common knowledge is to eradicate the mosquito breeding grounds.  NEA (National Environment Agency) found 80% of breeding grounds are actually right at home.  This however does not prevent one from mosquito bites because there are so many breeding grounds out there in the natural habitat that cannot be easily eradicated. 

The only effective way the author has found is to install mosquito screens at home and wear repellents outdoors to prevent contacts with the mosquito.  The article will concentrate on how to install these mosquito screens DIY and save money. 

Why the Screen?

1.  It is a permanent measure that will save "tons" of insecticides which is not only  harmful the environment but also the human beings;

2.  It cost next to nothing to maintain;  only occasional cleaning is required;

3.  It does not block out much sunlight and ventilation;

4.  It is aesthetically pleasing as screens are almost transparent;

5.  One can repair the screen easily using thread and needle

How Many Type of Mosquito Screens? 

There are many types of mosquito screens available in the market;   roughly,  they fall into 2 categories; the fixed and the removable type. 

The fixed type can often be done as simple as using construction plastic coated green mesh or net available from many local hardware shops;  the more sophisticated one will use special woven net materials.  They come in a roll form.  Some plastic coated green mesh can be quite brittle and are not suitable for screen making because they will tear easily during installation;  the better ones are woven type.  They all look about the same but the woven ones are thinner and has fibre threads.

The removable ones are mainly of woven net materials except it is first fixed onto a specially made PVC trunking and then attached to plastic magnets so that they can be removed at will for cleaning for example.  As there is a video made for the removable type,  this article will concentrate on how to install the fixed type.

How to DIY using Construction Mesh/Net?

To install the wire mesh onto the wooden window frames,  one can use small timber strips and a staple gun. 

Cut a piece of mesh slightly bigger than the opening and fix into position with timber strips; thereafter staple the timber strips onto the window frame with the staple gun. Making sure that the timber strip is thick enough to fit the staples to let it stapled onto the wooden frame.

To install the wire mesh to metal frames or concrete wall would require having to fix first and screw a small timber frame onto the metal frames or concrete using electric drill and fixing screws.  After that,  one can use the same method as fixing the mesh to the timber frame as described earlier.

How to DIY using Woven screens

These woven screen comes either with honey cone or square net form. 

They are stretchable and can be hooked onto velcro strip that usually come as a package as shown.  They will cost around USD$2/= from ebay suppliers directly delivered to your door steps.

The fixing is relatively simple and quick.  The velcro is first fixed onto wooden or metal frame work after having first cleaned the surfaces with industrial thinner or equivalent;  thereafter,  just lay the screen over without stretching and press the screen onto the hook of the velcro.

The trick for successful installation is NOT to stretch the screen when laying it over the opening.  Stretching the screen will cause undue pulling force on the velcro which can become detached easily,  leaving a hole;  then the only way to re-fix the velcro in position is to staple it using the staple gun.

Mosquito Screen for Sliding Windows

Most of the windows today are sliding type.  There are 2 ways to fix mosquito nets.  One is to fix it external either directly onto the window grilles or metal mesh or to construct a wooden frame as big as a window panel.  Fix the screen first onto the timber frame using the same methods described above then mount the screen as if it is one of the windows.

Sliding Screens for Doors

The screen for the door will be a bit harder to construct because it will involve a sliding type of screen. However,  one can construct the screen door cheaply using an aluminium or timber frame to slide it along a window curtain rail as shown. 

Allow horizontal and vertical adjustment in the brackets holding the curtain rail to get a smooth sliding.  There will be a need to install a pvc strips on the floor next to the screen door as a stopper to prevent screen door from swinging in and out or to and fro when the wind blows.

The curtain rail is easily available from any hardware store.  A sliding screen door can be made within a day or two for less than SGD$30/= ( $ 15/= for the aluminium frame,  $ 10/= for the curtain rail and $5/= for the screen and the angle brackets or stiffeners.)   If aluminium frame is used,  just glue the screen onto the aluminium frame and trim the edges after having the ugly glue parts concealed by using special timber strip of 5 to 10 mm width (from Diaso IMM store or Art's Friends at Bouna Vista MRT station).   

There are also special curtains made for the door and they are available for ebay.  The curtains have  magnetic strips on the opening edges to seal the curtains.

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 Q & A

 

1. Will the screens cut out natural lights and ventilation?

The mesh or net will cut not much lights and ventilation. The normal construction green mesh may cut by less than 10%;  the woven screen,  by less than 5%. The woven screen is almost transparent viewing from a distant of more than 2 feet away.  

 2. Wouldn't mosquito still get in through the doors?

Mosquito will like to rest on dark surfaces,  especially when the doors are colored dark. When one opens the door,  it is very likely for mosquito to be "blown" into the house by the "wind" of the door.  One way to prevent this is to have light colored doors;  the alternative is to place mosquito repellents near the door way and renew the repellents every now and then when they expire. 

3. Would the screens trap dust?

Yes.  Some dust will accumulate over time but vacuum cleaning will keep them clean again.

4.  I bought the woven type with velcro from ebay.  How do I hide the ugly edges?

The screens come with a 5 mm velcro strip which can be an eye sore when the screen's edges are untidy.  One good way to hide the ugly edges is to cut another velcro strip and press it onto the original velcro;  the alternative is to buy small 20 mm x 10 mm or smaller trunkings meant for electrical wiring to cover up the edges.  Fortunately,  only the windows at the corridor are exposed and need the edges to be covered up.

5.  Must we ensure that all openings are protected? Some are difficult

All openings in the house must be protected,  even the openings leading to open yards and door ways.  It will be useless to protect all windows and leave the doors open.  Install door closing device if needed be to ensure the doors will be closed at all time and also double quick.  There will always be a way to seal the openings.  Discuss this over with your carpenter or home builder

6.  Why do we need stiffeners for the sliding door screen?

The sliding door made from 12 mm square aluminium box section will be very unstable for a screen door of about 2.2 metre tall and 1.5 metre wide.   Stiffeners and angle plates plus cross bars will need to be added to ensure the screen door would not wobble.

7.  How to Prevent Sliding Door Screen from Swinging?

The sliding door screens made from aluminum frame are quite light and will swing if there are strong wind.   To hold down the frame,  one would need a floor track for the door.  The author used a long piece of 3/4" width telephone trunking as the floor track and 2 Nos of 5 mm stainless steel ball bearings as door slider at each end of the door screen as shown

Cut 2 short piece of aluminum channels and drill 2 holes on each piece.  The hole shall be made just slightly smaller than the diameter of the ball so that it will hold the ball in between the channel and the door frame.  After ensuring the ball bearing is free to move,  fit the aluminum channels and ball bearing to the screen frame using rivets.  (Tip: One can start drilling the hole one size smaller than ball diameter and use hole reamer tool or round needle file to enlarge the hole)

Monitoring Haze

24 June 2013

 

Introduction

Haze is here to stay as long as there are plantations in Sumatra of  Indonesia where fire is often used to clear the lands for agricultural purposes.   The haze will linger over Singaporein the middle of the year until October or November when North West Monsoon begins to blow from North towards Sumatra.

Is Haze Dangerous?

Haze is harmful to human's respiration system;  prolonged inhaling of haze particles will cause sickness and those with acute respiration or heart problems  may find it life threatening.  During the hazy days with PSI (Air Pollution Index) going above 100,  many will have to cancel outdoor activities and will be advised to stay indoors or wear N95 face masks outdoors.   

How to Monitor?

 

Using particle counters that can measure air particulates as small as 2.5 micron in diameters;  however, these counters involves laser technology and they are not cheap.  A cheap one will cost around SGD$300-400 and professional ones may be as high as SGD$30,000/=.  These counters are out of reach of most households.  Fortunately,  Singapore's NEA (National Environmental Agency) and Malaysia's DOE (Department of Environment) maintain websites during the period where one could get latest readings of the pollution indexes. The Singapore website provides 3 hourly as well as 24 hour readings whereas the Malaysian website updates the data once every 4 hours. 

The Singapore's NEA website can be found here.

The Malaysia's DOE website is here 
(Note:  this website is always in heavy usage;  accessible easily off peak)

How About Forecasting? 

The Singapore's NEA provides daily forecast in its website and the forecast is updated once a day.  However,  the forecasts are not often accurate for some reasons;  for example,  NEA forecasted that the PSI  will reach 300  on 23 Jun 2013 whereas the day's actual  maximum was around 110 and staying below 100 most of the day.

 

 

How Can We Confirm the Forecast?

Fortunately,  there are very comprehensive free weather forecasting website available for Singapore;  they are:-
 

a)  Windalert

b) Time anddate

c)  Windfinder

One can use their wind direction predictions together with the regional haze map  to check and confirm the forecast.

How?

One will need the following tools:- 

a)  A regional haze map showing the geographicallocation of the haze(free from NEA);  for example

  

b)  The prediction of the wind directions given by the 3 free weather sites;  for example,

 

First check the haze map.  If Singapore is not in or near the haze cloud as is shown in the above haze map,  Singapore is likely to be free from haze for the day. This should be further confirmed by the wind directions. If the wind direction is not pointing East or North East  and is pointing North or North West like being shown,   most likely one would enjoy pollution free sky in Singapore and vice versa.

 

Planning for a Trip to Malaysia? 

Many planned to hide from the haze and go to Genting Highland for holidays;  some went to Penang. Is it safe?

The Regional Haze Map,  the DOE and wind direction predictions will show that it is not advisable to head to Kuala Lumpur,  Genting,  Pahang,  Muar or Melaka at the present moment.  The haze cloud and the wind directions are heading North and North West.  Penangat present is free from pollution but will soon be clouded with haze if the prevailing North West wind is strong.

Planning to Go Out?

One could check the sky condition and also the webcam picture from the following sites for conditions of the haze. 

a)  Webcam @ Admiralty Road

b)  Webcam @ Kent-Ridge

c)  Webcam @ Raffles Place

How To Conceal Car Camera Wirings

20 June 2013
 

Introduction

Car camera is a plenty nowadays in the market.  They are cheap around SGD$50/=. It has quick to become an essential piece of equipment but unfortunately,  the camera must be retrofitted as it is a non-standard item for most cars.

What are the Installation Problems?

One problem is how to conceal the "long and black" cable that is getting electricity supply from the cigarette lighter.  Many have run the cable exposed as shown which is quite unsightly.
 

 

How to Conceal?

Fortunately,  most cars today are fitted with loose panels and ceiling board so that they can be easily removed or interiors accessed without having to tear them down.  This article will use 2011 Toyota Yaris Spirit as an example to illustrate how the wiring can be concealed.

 

Step by Step

1.  First,  remove the windscreen side panel

 

The side panel is held in place by two bottom clip and special clip on top as shown

 

 

To remove,  first use finger to pry open the side panel at the top to expose the special clip.

 

 

 

Then twist the base of the special clip so that the hook is in-lined with the slot of the side panel for the panel to be pulled out sideway. 

 

 

 

Remove the side panel, paying special attention not to damage the air bag assembly for the side windows

 

 

2.  Remove the instrument subcover

 

Remove the 2 screws and pull the cover down to release the 2 catch as shown.  This will expose the interior parts above the clutch and the brake panel

 

3. Thread wires through opening

 

Thread the wire through the opening as shown below.  Note that the author has a specially made cable and a box to house other electronics;  otherwise,  the stock cable can just be run through here to the cigarette lighter without mounting the box.

 

 

4.  Fixing wire to instrument sub cover

 

 The cable can be run across the instrument sub cover and fix in position by bluetac as shown. 

 

 

5. Running cable along the roof

 

The cable that run across the roof and can be hide inside the roof by prying open the edge of the ceiling board using just fingers. 

 

6.  Assembly back components

 

Reverse the dismantling process to reinstate all components back to their original position

 

7.  Completed Wiring

 

The completed wiring installation is as shown below.

 

 

 

 

 

 

 

 

 

 

DIY Air Filtering Face Mask

20 June 2013

Introduction

When the PSI reading goes above 200,  it will be good to wear a face mask even at home unless one has a proper and efficient air filtering system in the room. What happen if you and the stores run out of face mask?  It is happening now in Singapore.

DIY a Face Mask

For ladies,  they could have used their  bra but for most,  it is better to find other materials.  One of them is the non woven electrostatic fibre paper that has been used extensively for  floor cleaning. Tissue paper can be alternative source but they are too fragile to handle.

Whats Needed? 

1.                  A box of electrostatic fibre paper easily available from any convenience store @ SGD$1/=

2.                  Four rubber bands

How to Construct?

Take one sheet of fibre paper and fold it in halve.  Tie two rubber band together in a link and tie the rubber to the end of the paper.  Wear it with one end of the rubber band to the ear.

If needed be,  insert a trash bag tie and staple it to the top of the mask for closing up the gap between the paper and the nose.. 

Adjust the length of the rubber band to suit comfort wearing..  If one layer of paper is not sufficient,  use 2 layers.

Disclaimers:  These are not proper substitute for commercial face mask.  The method is untested.  It is intended only for emergency use when one runs of face mask in the stores.

How to Seal the Water Leaks from Ceiling?

17 May 2013

Introduction

Staying in high-rise buildings will have this problem of water leakages from the ceiling.  The water from the upstair neighbour can find its way to your apartment.  It will bring social as well as heath problems if it is not solved.  This article will present a way.

Why  the Water Leak?

Concretes are porous and sometimes,  there are crack lines caused by concrete spallings and water can find its way through these crack lines.

What are the Solution?

The best solution is to talk it over with your neighbours to track the cause of the leaks;  sometimes,  it is caused by choked drain and sometimes,  by pipe leaks especially if the neighbours have the pipes  embedded in the walls.  Negotiate a way to repair the water leaks.

The alternative not as good is to seal the ceiling to make it water and air tight on spots or areas where leaks were found. 

The author used both methods above  to prevent the recurrence of ceiling water leak for over few years now.  This article will discuss how to seal the ceiling.

What you will need?

1.  Light weight board such as polystyrene board

2.  Matching color silicone glue with glue gun

3.  Double sided tapes for building work

Of course,  one  will need a  ladder to reach the ceiling to place the board.

Step by Step

1)  Clean the ceiling at areas where the light weight board will stick to the ceiling;

2)  Place the double sided tape on all edges leaving about 10 mm from the edges;

3)  Use the glue gun and place silicone glue in the centre of 10 mm space between all the edge and the double sided tape;

 

Now one is ready to stick the board to the ceiling and left with the last step

4)  Squeeze some more silicon glue at the edges using glue gun and seal the edges all round;  smoothen out the left over glue to complete the job

Why?

The double sided tape will hold the board onto ceiling as well as to provide the first water seal;  then the seal is reinforced by silicone glue to give a water and air tight space between the board and ceiling.   This air tight space will resist water entering unless the air inside the space escaped or replaced by water.

Will the Air inside the Space Escape?

The air will escape when the crack line is big.  Fortunately,  most concrete crack line are small and quickly filled up with water which will prevent the air inside the sealed space from escaping.

Isn't Polystyrene Foam Board Toxic?

 
Foam insulation board should not be left exposed in building interiors.  Most building regulations will require the forms to be protected with fire rated materials; they may give off thick acrid or toxic black smoke in a fire, making it difficult to safely exit the burning building.  Therefore, be careful not to use too much foam insulated materials without fire protection.

How to Keep Bicycle Tires Inflated?

17 May 2013

Introduction

We own 8 bicycles.  Adults will use them to commute to MRT and nearby sundry shops; the kids use them for leisure riding.  There is a problem having to inflate these bicycles as the tires will go flat after a week or so.  The article will present a simple and effective method that will keep tires inflated for months.

Why Tires Go Flat?

Just like a balloon,  most bicycle tire rubbers are thin and porous and has tiny microscopic pores that allow air to escape over time.  Sometimes,  air will leak through the valve stem which should not have happened if the valve is new. 

How to Prevent?

To seal the microscopic pores.   The author has tried various methods like using diluted white glues,  liquid glues and combination of other chemicals but found it most effective to use liquid sugar.

How to Prepare?

One will need the following:

1)  A 30 mls plastic container

2) A 5 ml syringe holder

3) A valve opener

Preparing Sugar Solution

Place about 6 tea spoon to a cup and add about 25 mls of hot water,  stir till sugar is completely dissolved; the solution should be sticky but flowable;

Using the syringe holder,  suck up as much solution as possible and inject into the tire tube as shown.

DOW Peaked?

11 May 2013

Introduction

Has DOW peaked? This is one question that many wanted answers.  This article will present some random thoughts on whether DOW has peaked or near peak.

DOW Theory

In the past,  many used DOW theory to determine whether DOW had peaked.  Under some specific conditions especially when DOW Transportation Index ($TRAN) runs about 25% below DOW,  DOW Theory effect has known to kick in to indicate a market crash ahead.  True enough $TRAN was -38% below DOW on 16 Feb 2000 before the Dot.com bubble crash and was -26.2% on 9 Jan 2008 before the Sub-Prime problem.  However,  $TRAN never hit -25% this time.   It only managed to hit -21% on 21 Sep 2012.

No Market Crash?

 

It is very hard to tell at the moment; however, the following details tend to indicate that something might happen in the near future.

What Could Have Saved The Market on Sept 2012?  

Fed announced unlimited QE on 13 September 2012.  It is believed that this Fed's announcement saved the market from further deterioration. The monetary policies could have distorted the market like it has distorted the yield curves.   The market is so flushed with M3 money supply that has enriched the market instead of the economy.  Lets further examine the dangers lurking ahead.

Signs of Market Crashes

From the following charts,  one can identify 3 common signs in addition to the DOW theory:-

a)  There is a divergence between $TRAN and CRB,  the Commodity Index, few months before the crash; 

b)  The Bank index $BKX is always leading the crash;
c)  CRB will then pick up and rise towards the DOW peak.

Does the Present Market Has the Signs?

The present market has only the first sign i.e. a divergence between $TRAN and CRB.  It has not fulfill the DOW theory nor the bank index,  $BKX,  has started to decline.   CRB is still at its downward trending.

Can a Crash Occur? 

It is premature to tell at the moment;  however,  the following charts are telling us something could  happen in the  near future.   This is because:-

a) $BKX,  the banking index,  is about to make a triple top;

b)  Nikkei is at all time resistance

What Other Say?

Many analysts said they are bullish about the present market.  The Professor of Doom, Dr. Nouriel Roubini said that  this bullish market trend could go on for the next 1 to 2 years.  

then there is Prof Paul Krugman who said Bernanke was not blowing any bubble right now.  Even the Gloom, Boom and Doom, Dr. Marc Faber, was not sure and now said   "a correction can occur".

However,  Warren Buffet and other billionaires were dumping shares at an alarming rate.   Warren Buffet once said "Going bearish when others are bullish"

Update 1:   15 May 2013

The bank index,  $BKX,  broke the long term resistance line last night with a 1.8% gain.   This has pushed DOW up another 0.81%,  Nasqaq by another 0.7% and S&P by 1%.   However,  $BKX has also touched the upper bounce of the rising channel.   Is this breakout sustainable?  There is no way to tell as Yahoo and many other website stopped providing volume figure for $BKX since Jan 2013 for some reasons. 

BTW,  the Fear and Greed Index of CNN Money jumped 3 points to 87 points last night increasing the weekly gain by 10 points.  It will soon reach its peak and ready another round of correction

Would Stocks Go Higher?

8 May 2013

Introduction

Many have been waiting for the stock market to correct its prices but so far,  it never happen;  instead,  the stock prices have been going higher and higher. Lets examine why.

Monetary Policies

 

We all know that US,  Europeand Japanese central banks have monetary policies that said to have the effect of stimulating the economies.  The central banks have been buying assets trying to inject large amount of money into the markets with a presumption that the money would eventually find its own way to the economy.

Is It Working?

According to the Now and the Future that monitors the key statistics of US economies,   the Fed's present monetary policies did not work for the USeconomy.

The chart of "Money supply M1, M2, M3"  clearly shows that the M1 and M2 money supplies have been declining since mid 2011 whereas the M3 supply has been increasing steadily after early 2012. The M2 is a key economic indicator whereas M3 supply includes M2 plus large and long-term deposits that belongs mainly to the banks and institutions. 

Further,  the velocity chart which tracks the speed of money through the economy has been  decreasing ever since mid 2008.  In short,  the money intended to stimulate the economy has never found its way into the economy as expected. 

Why Stock Prices Are Rising? 

The "printed money" presently enriches only the banks and institutions. They have been buying up the stocks.  This is because USDollars,  bonds and commodities are not attractive at the moment.  USDollar has been suppressed and depreciating ever since monetary policies were implemented;  on the other hand, bonds have negative returns because the yields of most countries are at record low.  As for commodities,  the prices has plunged since early 2011.  What is now left is the stock market which have been rising since March 09. 

Isn't Stock Market Overpriced?

The stock prices of the present market are slightly higher than the mean average as reflected by the Shiller's PE10 shown here

The present Shiller PE ratio is 24. Though the PE ratio is higher than the mean or median,  it is still way below the max of 44.20 recorded before the dot.com bubble.  In other words,  the Banks and Institutions who are flushed with printed money is presently perceiving that there are still rooms for stock market prices to climb.    It is however viewed that the greedy market players will continue to lift the price of stock market to a point until Fed starts to unwind its monetary policies or increase the interest rates.

Update 1: 11 May 2013

There are signs that some indexes such as the Bank ($BKX) and the Nikkei have peaked and is developing further signs of market crash ahead.

References
DOW Peaked?

Bed Cooler - A Worthwhile Investment

30 April 2013

Introduction

One of my family had a backache recently and had to be bedridden for about 2 weeks.  One of the many things I did was to buy her a Gel filled cooling pad.

But this pad only has gel inside and required to be cooled every now and then by the fridge.   Bed cooler on the other hand has its own chiller unit and provides constant cooling to the bed.   This article will detail the experience and the research that I have done on bed coolers. 

 

What is a Bed Cooler?

In the market,  there are several type of bed cooler.  Some pump air into a special made mattress;  others,  pump chilled water into tubes or special mattresses.

This article will concentrate on the latter.

 Most bed coolers have the following 6 components:-

1)   A chiller unit which takes out the heat from the water returns from the bed

2)   A small pump which circulates that water to and from the bed

3)   A set of tube usually made of silicone or a special mattress with sealed grooves that allows chilled water to flow within

4)   A temperature controller that regulates and controls the temperature of the chilled water

5)   A water reservoir that stores up the chilled water

6)   A special mattress or set of tubes that allow chilled water to run underneath the bed sheet

 

Different Types of Bed Cooler

In the market,  there are basically 2 different type of bed cooler.    Commonly seen are bed coolers with a small electronic Peltier chillers that run on 12 or 24 volts supply.  The package comes with a control unit that contains all the first 5 components. The special mattress is always coming as a separate unit.  It is "plug and play"  type. 

This type of bed cooler is sold around SGD $800/= for single bed and about SGD$1,300/= for a double bed.

The other type not commonly seen are the bed coolers with an ordinary chiller unit that runs on freon gas.  Though freon chiller unit is 75% more efficient in term of energy usage,  it is not portable and requires piping installation.

What are the Advantages?

1.  Energy Savings

Bed cooler will cool the bed to about 23C-25C which will reduce the need to have room air conditioners turning on all the time;  thus can save 50% to 90% of the electricity consumption according to a test carried out using data acquisition method.

if the bed cooler is of the silicon tube type that runs tubes underneath the bedsheet,  the uneven temperature distribution can be even out by placing a Gel filled cooling pad on top of the tubes.  The gel pad can save more electricity.

2) Balancing Body Temperature

Bed cooler will remove the body heat and keeps that body temperature to a desired temperature, comforting the body  and balancing the body's temperature as one sleeps on the bed. 

Most Chinese believe anti-inflammatory plasters that can relieve body pains as the plasters have camphor or menthol in them. They provide cooling sensation  that will  relax the body's muscles.  The bed cooler will also relax muscles and especially true  for relieving muscle clamps.

3)  Insomnia and Skin Peelings

The author used to have mild insomnia, having difficulty going back to sleep after waking up in the middle of the night. This sickness has not occurred since we have the bed cooler.  May be the cooling of the back and body has the effect of bringing about a better sleeping behaviour. Also noticed is that the hands and fingers are not as dry as before and skin peelings have much reduced.

4)  Preventing Bed Sores in Hospitals

The hospital mattresses and pillows are always lined with PVC covers instead of linen sheets and other materials for hygienic  reasons and ease of cleaning.  Unfortunately,  it bring about a bed sore problem to those patients who are unable to turn their bodies and backs.  Nurses could help but there are limitations.  Bed cooler is the answer.   It can be designed as part of the hospital bed with quick connect-disconnecting devices that have been used for filling up petrols during car racings.  

 

Other Information

 

1) Blanket Covering

It is a good practise to cover the bed with blanket first and turn on the bed cooler half an hour before going to bed. With the blanket covering, one could get some cooling for the whole body. If one can construct a movable and collapsible hood with a big and clear plastic sheet or cloth and attached it to the head board such that it can be pulled it down to cover over the head, one can even get some cool air to pass through the head as well.

2)  Water Treatment

Unless the circulating water system is totally sealed and free from air contact,  bacterias will form and will foul the water to give awful smell.  In that case,  there will be a need to treat the water either chemically or otherwise to get rid of the bacterias and chlorinated water is often used.  Therefore,  it is important for the bed cooler to be constructed of materials that can withstand such water treatment process.

3)  What  should be the temperature setting?

It will depend on each individual.  Some like it cold while others like it warm.  Our body temperature is around 37.7 C,  it is therefore more comfortable to set the bed cooler to not less than 10 C differences or around 27 C;  a temperature setting around 29 C -30 C will be comfortable although it might take time to cool the bed.    One can also operate the bed cooler together with normal air conditioners which can be set to lower the room humidity for comfort cooling.  In this case, the room temperature will around 27 C instead of normal 24C-25C to save electricity. 

 

What about rheumatism?

There is no direct body contact with water.  However, Scientists have found that weather or temperatures and humidity's variation doesn’t cause rheumatism and doesn’t damage joints  but they did find that weather does affect the severity of rheumatic pain. This is because bones, tendons, muscles, and joints have different densities and expand or contract differently when exposed to drops or rises in temperature and humidity.   These weather sensitive people may found it uncomfortable with this kind of cooling. 

 

Can One DIY Bed Cooler?

 The author has DIY a bed cooler using a second hand aquarium chiller and silicone tube that is used to provide air to aquarium tanks.  It has been giving satisfactory results.

References
Cut Cooling Bills by 90%
Spot Cooling Cuts Aircond Bills by 50%
DIY Bed Cooler
Bed Cooler for Ng Teng Fong Hospital