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

Head and Shoulder Pattern in Gold Price

13 April 2013

Introduction

The price of gold plunged 5% Friday to its lowest level in three years. Some said it was due to countries like Cyprus dumping gold to pay for the debts;  other said that the economists were increasingly worried about the economy's forward momentum heading into Spring.  Whatever the reason,  lets examine Gold's technical to see where it would be heading.

The Head and Shoulder Pattern

One of the very common pattern in stock analysis is head and shoulders pattern.  It is a reversal pattern and it is most often seen  in uptrends.  It is quite reliable pattern when it is found in an uptrend.

Such a pattern will see buyers coming in to form the left shoulder and the neckline with fairly large volume.   As sellers sell at the highs and push down the price towards the neckline to form the left shoulder,  the buyers return to push up the price which may not necessary be the new high;  however,  the volume will suffer.   When the right hand shoulder is completed and touches the neckline,  sellers  will begin the dumping process with price falling sharply at large volume to complete the pattern. The price may test the neckline as it form the head and shoulder pattern.

After having broken the neckline,  the selling will not stop until a target is reached and this target is found by measuring the distance from the neckline to the top of the head or sometimes,  the shoulders.  When the target is reached,  the price will re-test the neckline.

Is this Pattern Found in Gold Price?

Gold price has developed exactly the same head and shoulder pattern after yesterday's fall except the head is much smaller in size compare to the left and right hand shoulder.

It is likely for Gold to head lower until the target price is reached

Update 1: 18 May 2013

Gold has failed to break the neckline in its attempt recently and now has broken the bear flag resistance of 130.3 except that the volume at the break was low.   The full STO is now at oversold region and the RSI is set for a rebounce.   However,  the ADX (not shown) is telling us  that there may be accelerated declines ahead.  The price development next week will determine the direction.

Update2: 26 June 2013

Gold has broken down again after forming a second neckline which does not usually happening.  The market might not be convinced that the correction was done and there was another opportunity for a second head and shoulder (H&S) to be formed.    This second H&S would appear to set Gold price back further down and have a target price which is less than $1,000/=

Update 3 :  18 August 2013

Gold price broke neckline 2 on around 13 August 2013 on lighter than expected volume.  The breaking down of neckline 2 could be QE tapering related.  As the volume is low during the break up of neckline 2 ,  there is a likelihood of Gold may revisiting neckline 2 in near future if the QE tapering news is reversed. 

What Size Aquarium Chiller?

11 April 2013

Introduction

Sizing a chiller for the Aquarium can be a difficult task as the tanks come with various dimensions and sizes;  also,  some aquarium set up can be so different that one would have to work out the detailed heat gain and loss to size a chiller.  This article will give 2 methods on sizing a chiller.

How to Select the Right Size Chiller

Many aqua and reef enthusiasts pick up some knowledge here and there. Some uses the one size larger rule and some just blatantly use figures provided by the manufacturers. Some suggested that chiller should be large enough so that it won’t run longer than half an hour on each start. Some preferred shorter operating time citing lesser wear on the compressor.

The correct chiller sizing should depend on heat loads transmitted into or out of the tank. There are basically the following heat losses/gains that can be found in an aquarium tank;

1) The heat gain from the light fittings
2) The heat gain from the pump or in-line filter
3) The heat gain transmitted through the exposed glasses
4) The heat gain from the occupants
5) The heat gain through surface and the heat loss from evaporation
6) Others heat gain such as those from internal circulating pumps, wave makers etc

As the calculation involves complicated thermodynamics and air conditioning engineering, it would not be discussed here. Those interested can read up this article.

Most enthusiasts just use rules of thumb. The thumb rule of using one size larger appear to be more appropriate because the manufacturer’s guideline often did not consider the extra heat load from the other equipment such as lights, pumps etc; also, the chiller will age and lost efficiencies. Then one might want to add more equipment such as more pumps in future. Some manufacturers could also over-rate their chillers.

Method 1:  Using JBJ Website

JBJ has a website that one can use to size various chillers.

Please note the following when using the website:-
a) For metric to imperial conversion, use the formula degree F= degree C * 9/5 +32 and 1 US gallon = 3.8 litres;
b) Remember that actual water temperature refers to maximum water temperature which should be around 30C or 87F for Singapore;
c) A 40 watts fluorescent fitting will give 50 watts of heat; 40 watts for the lamp and 10 watts for the ballast (25% for magnetic ballast, 20% for electronic ballast and 15% for LED driver);
d) Assume full tank volume and not actual water volume to be safe.
e) It is still good to up one size larger after the calculation.

The term horsepower (HP) is often used for sizing a chiller. One can take that 1 HP=2800 watts of cooling power. Divide that by COP of the chiller (1.3 for freon and 0.55 for Peltier), one should get roughly the power inputs in electricity watts.

Method 2:  Using Table Selection

The following were assumed when working out the table:

1.  The Bulkhead heat load is around 0.6 watts per US gallon;
2.  The pump heat load is around 0.5 watts per US gallon;
3.  The overhead lighting load is around 4 watts per US gallon;
4.  The maximum temperature across the glass is 5.5 degree C

The manufacturers appear to suggest the chiller should be sized such that the chiller should cycle on 15-20 minutes an hour for chiller to run about 6-8 hours per day. Depending on the setting of the temperature and the water flow rates, it may be normal for chiller to run for 1 hours and stay off for 2-3 hours before the next cycle.

Other Relevant Sites
tinyurl :  https://tinyurl.com/ybyepw7p