Frequently Asked Questions

Frequently Asked Questions – Evaporative Cooling

Q Can Mercury Heating and Cooling run the Evaporative cooler through the heating ducting?

A No, unfortunately the airflow for Evaporative cooling is too large to fit through the smaller heating outlets. Evaporative coolers have their own separate ducting network in the ceiling.

Q Is this the unit (Evaporative Cooling) where you must leave your windows open?

A Yes, you must have an exit point for the air that is adding to your house. It must vent to outside so that the cooler can continue to provide more fresh, cool air. No hot air from outside the house can come inside because the Evaporative cooler creates positive pressure inside the house, so the air inside is busy rushing out the window or door openings. Think of the house like a balloon. If you pop a hole in a balloon, no air rushes into the balloon because the air inside is busy rushing out.

Q Does Mercury Heating and Cooling only install one brand?

A No, we offer a range of the best brands.

Q Are they noisy?

A No Evaporative coolers are silent, just like a fridge, ducted heater or other appliance with a fan. The technology in the fan and motor has improved drastically so noise is now no longer such a concern. The unit is usually installed over a wet area (bathroom or laundry) and is sized and installed so as to minimise the noise inside and outside the house.

Q Does Evaporative Cooling work when it gets really hot or muggy?

A How well the Evaporative cooler works is dependant on the outside temperature as well as humidity levels. The drier the air is, the better the cooling effect. On muggy days it is still better to have Evaporative cooling than to not have it, but its effectiveness will be slightly reduced on days of high humidity. On hot dry days, Evaporative cooling is quite simply the most efficient and effective way of cooling. Luckily in Melbourne we very rarely have days of high humidity.

Q How cold will it make my house on a hot day?

A Depends on temperature and humidity levels. An Evaporative cooler works for a few different reasons.

  • It lowers the effective temperature of the air (3-4 degrees) due to air-flow over the body.
  • It lowers the actual temperature (between 6 – 10 degrees) through the evaporation process.
  • Reduces radiant heat from the house. Airflow prevents physical house absorbing heat.

Q Is this Evaporative reverse cycle? Does it do heating as well?

A No, it is just Cooling – it cannot be combined with a heater. Although, Mercury Heating and Cooling can install all types of reverse cycle air-conditioning and heating systems.

Q Will water restrictions impinge on my use of an Evaporative Cooler?

A No worries! Evaporative cooling does use water but are not affected (and never have been) by water restrictions. They only hold and drain 6 – 10 litres of water at the end of the day when the unit is turned off. The system will use more water in the Evaporation process (which is how it cools the air), but this is a very small proportion of a typical households water usage. A full week of Evaporative usage will often be less than the amount of water used in a normal household bathroom in one day.

Q What about service and maintenance?
A Same as ducted heating – a service and clean should be performed every 3 years but Mercury Heating and Cooling takes care of all services and will contact you at the appropriate time. If the maintenance free features are fitted then there is NO SEASONAL MAINTENANCE. NO COVERS, NO WASHING PADS, NO DRAINING. The unit will automatically fill up with water, drain the water, flush the pads and seal the unit after EVERY DAY of use.

Q How often should you change the filters?

A Because the unit washes and drains itself automatically, and under normal domestic usage, the pads will need changing every 8 – 10 years.

Q How long does it take to install?

A The majority of jobs are finished in 1 day. A licensed plumber and A-Grade electrician perform the installation and provide all warranties and Certificates of Compliance on Plumbing and Electrical.

Q Can you shut down the outlets in rooms not being used?

A No, there is no need to. Simply open the windows in the rooms being used (i.e. lounge/living room) and the air from other areas of the house not being used (i.e. bedrooms) will vent through living area windows or doors.

Frequently Asked Questions – Gas Ducted Heating

Q Can I turn off outlets if I am not using them?

A Yes, it can be more efficient if you close off outlets in rooms that are not used. This is called “zoning” – and it is possible to have it done electronically i.e. You can turn off a formal living area by pressing a button on the wall controller. However, depending on the size of the heater, you must have a minimum of 5-7 outlets open at all times.

Q Can I get cooling through the same system?

A Yes, this is called Add-On Air Conditioning. The ducting must be up-sized to allow for the larger airflow that Air Conditioning requires.

Q My house has a concrete slab floor, does it work through the roof?

A Yes, it is common to have the system installed in the ceiling. Mercury Heating and Cooling will make sure that the system is adjusted to reflect this, i.e. the sizing of the fan has to be large enough to blow the heat down to the ground, the outlets must allow the air to flow through freely so it can reach a low level and the “Return-Air grill” should be also be at a low level.

Q Which is the best model for me?

A All heaters have a star rating to indicate operating efficiency. The more stars the cheaper it is to run, but the greater the initial purchase cost. So to recommend a specific model, Mercury Heating and Cooling will assess how long you intend to live at the house, how large the house is, what temperature and how often you intend on using the system.

Q Can I get a remote control?

A Yes, but because the system judges the house temperature via the thermostat inside the controller, we recommend the controller be mounted on a wall in your main living area so that it can read and communicate the correct information to the actual heater.

Q What if I just want to heat one room or area?

A Radiant Panel heaters or Fan Forced Heaters are designed to heat a single area. There are different sizes to match any room size.

Q What about service or maintenance of heating systems?

A The “Return Air filter” should have a vacuum run over it regularly and the unit requires a technician to service it every 3 years, but Mercury Heating and Cooling will contact you when this falls due.

Frequently Asked Questions – Refrigerated Air Conditioning – Split Systems

Q How big does my unit have to be?

A Because no two homes are exactly the same, a consultant from Mercury Heating and Cooling will measure and quote on the correct size. As a rough guide, 1kW will heat/cool 1 square of home.

Q If I leave the door open will it blow through and cool the bedroom or other rooms?

A Usually a split system is designed to cool only the room that it is installed in. If it is oversized then you may get some “drift” into other areas, although this is not recommended.

Q Can I get it in cooling only?

A Yes, split systems can be cool only – but the difference in price with a reverse cycle (heating and cooling) is very small – usually less than $100 – so most people choose a system that heats and cools.

Q Can I have multiple indoor units run off one outdoor unit?

A Yes, Multi-Head splits are an option. Although, the installation price can increase and effectiveness decrease if the indoor heads are located a long way away from the outdoor compressor. A consultant from Mercury Heating and Cooling is happy to advise on the most suitable options for the specific needs of your home.

Q Which Refrigerated Air Conditioning brand is the best?

A There are a number of brands that we recommend. Mercury Heating and Cooling can supply and install a range of the best brands. Some brands suit certain applications better than others.

A consultant can advise you about which brand is most suitable.

Q Can I add an air conditioner to my ducted gas heater?

A Yes this is called Add-On Air Conditioning.

Q How often should I service my Refrigerated Air Conditioning unit?

A The filter should be cleaned regularly. A light on the unit will indicate when this is necessary.

Q If I leave the door open will it blow through and cool the bedroom or other rooms?
A Usually a Wall split system is designed to cool only the room that it is installed in. If it is oversized then you may get some “drift” into other areas, although this is not recommended. A ducted split system is designed to cool multiple rooms at one time, or you can choose a Multi Head Wall Split system.

Q How much do Refrigerated Air Conditioning systems cost to run?

A It is very hard to give an estimate of the running costs as there are so many variables – these include the price of electricity, the outside temperature and the temperature you set. The insulation and window area also has a big impact on how well the house retains heat therefore the running costs.

If you look at your electricity bill, it will show you your current price of a kW p/h which could be around 15c. If the unit is a 12kW system, remember it is an Inverter so it only uses as much kW as is required – the operating range is 14kW on high side down to 5kW on low side.

So when you first turn your unit on and it’s a very hot day then the max cost is 14kW x 0.15c = $2.10 – this is the max hourly cost. Because we have sized the unit properly taking into account the floor space and heat load factors, and because we use excellent r1.0 ducting that minimises heat transfer through the duct, the system will cool you down effectively and then the inverter will ramp down to a lower level of 10kW and then 8kW and then 5kW when it is operating at 5 x 0.15c = $0.75 per hour.

This is now when the insulation and thermal properties of the house come into play – a house with excellent shading on the windows, and high performance glass/double glazing and excellent insulation in ceiling and walls will retain its temperature for a long time so the unit will continue to operate at a lower level.

If the house has lots of windows facing north and west without any shading or poor insulation it will heat up faster and cause the AC to come on earlier and stronger, or if the temperature is set for 21 as opposed to 24 then the unit will have to operate much higher and longer to take off the extra 3 degrees thus the running costs are higher.