Heat Recovery and Ventilation FAQ
Does every house need one?
It depends on the house. An old house with ‘natural’ draughty ventilation does not need one and there would be no benefit in installing one. However, if you are renovating an old house and intend to seal it and insulate it then yes you do need one. But you must insulate before you ventilate.
Do I need a secondary heating system if I am using the MTD-ERV heat recovery system?
Yes. The MTD-ERV is not a heating system. It recovers the heat you would ordinarily loose through standard ventilation wall grilles and trickle vents by extracting warm stale air from specific rooms and passing it through a heat exchanger before dispelling air to outside the dwelling. Then the cold air coming into the house passes through the other side of the heat exchanger and is warmed to 97% of the air being taken from the house – this air is then supplied to specific rooms.
What is the best type of heating to use with this system?
The unit recovers the heat from the air in the room. It doesn’t matter if that heat was generated by wood pellet, oil, gas, electricity, geothermal or any other source. However, it is important to look at a heating system that will suit your needs.
Do I need two vents in every room of the house?
No. We concentrate on providing fresh filtered air where it is most necessary and taking the air from rooms where it has the poorest quality. You supply fresh filtered air primarily to the bedrooms and other occupied areas and extract stale air from bathrooms, toilets, kitchen and utility rooms.
What are the main noticeable differences in the house?
The main difference people notice is
1. No fungal growth in bathrooms or bedrooms.
2. No condensation on windows.
3. Fresh smelling bathrooms (air is constantly being changed no need for air freshener.)
4. Less dust (windows kept closed all air in to house is filtered) less spiders they feed on
dust mites.
5. Extra security (windows closed no need to part guard alarm)
6. Quieter house less outside noise as windows are kept closed
7. Wake up feeling refreshed instead of groggy (due to lack of oxygen)
I suffer from asthma, how will the unit help me?
We use the highest grade cartridge filter currently available to us which is an EU F8 rated filter. This type of filter removes 100% of atmospheric dust, 100% of plant spores & pollens, 100% of dust mites and dust mite excreta, 100% cement dust, 100% of bacteria <5 microns, 88-97% of bacteria 1 micron, 88 – 100% of carbon staining and 75-97% of smoke. The fresh filtered air is concentrated in the occupied rooms and the overall air quality within the house is significantly increased also there is a huge reduction in dust particles and pollen entering the home.
How often do I have to replace filters and how much do they cost?
Under normal conditions the filters will only need to be replaced every 18-24 months. The filters cost €40 each plus VAT and are available directly from ourselves.
How noisy is the unit?
Our systems are silent. You will not hear it at all – even in the quietest house in the middle of the night. The MTD systems are designed with acoustic supply ducting throughout from start to finish. Also, the termination valves in bedrooms are low convection acoustic valves.
How much does it cost a year to run?
The systems vary depending on the size of the dwelling. A system in a 2,000 sq.ft dwelling would consume on normal level between 20 - 25 Watts of power which based on a rate of 12.73/Kwh is under €30 per year. However, when the units speed up during showers etc the power momentarily increases to around 80-85 Watts. If you allow around €40 - €50 a year running costs you will be covered.
How often should the unit be serviced and how much does it cost?
The unit should be checked at least once every two years. The service check is generally around €80 + VAT call out charge plus consumables.
Should I turn the unit off in the summer, as I like to open the windows when the heating is off?
No, the systems are designed to run 24/7. In the summer if you are only opening the
windows to cool down you will get a better effect from the MTD system. The units have an
automatic summer bypass to prevent the incoming air travelling over the heat exchanger.
What happens is the moist warm stale air is taken out and fresh ambient air is brought in.
Because the air is moving throughout the house the effect is ‘comfort’ – good air quality.
What size house will the units do ?
MTD have a wide range of units. We have residential domestic systems designed to work in dwellings as small as 50sq.mt up to 700sq.mt. Larger units are available but they are more commercial in size and not as efficient to operate.
What warranty is on the MTD units?
There is a two year warranty on all MTD systems.
Where does the unit go in the house?
Generally the unit is installed in the attic space or in a utility room. It can be adopted to fit anywhere in the house. It can even be fitted outside but this will require additional installation. An insulated weatherproof enclosure must be supplied.
Can I install it myself?
Yes, If you are handy & into DIY there should be no problem. We will help you as much as possible with any questions. We can also provide a full detailed installation manual.
Can my builder install it?
Absolutely. although these systems are relatively new to the Irish market they have been used extensively throughout the rest of the world for decades. Traditionally, the plumbing or electrical trade carry out these installations. We will guide your builder through the whole process.
Can I close up the 4” hole in the wall in my rooms?
Yes, you can seal up your house as tight as possible as you will be getting a constant supply of fresh air so you & your house can breath.
Will it comply to the new building regulations?
Yes, the new regulations are derived around airtight construction (new houses will not be allowed to use the hole through the wall vent). All new dwellings built with airtight construction will require a MVHR (Mechanical Ventilation Heat Recovery) system or a PSV (Passive Stack Ventilation) system.
Can this unit be fitted to an existing building?
Yes, provided there is a sufficient level of insulation. Bungalows are very straightforward while two-story houses & dormer houses require additional building work. Alternatively, as a compromise on two story houses you can supply the upper level only this will supply air to bedrooms and extract from bathrooms & landing.
What happens in a power cut?
In a power cut the unit’s will not operate, this however will not have any immediate effect on you or your house. Most power cuts last only one or two hours and as the ducts are open to the elements there will still be a small air flow. However if you are concerned with this issue we can supply a UPS (un-interrupted power supply) this will allow your unit to remain running in the event of a power cut.
Where does the steam from the shower go?
There is a drain on the back if the unit which is connected to your overflow in the attic or other overflow. This is the condensation drain for the heat exchanger.
Can I change the filters myself?
Yes. It is very simple you just pull off the front cover and the filters just slide in & out.
How will I know when to change the filters?
The filters can be changed at every service (every two years) alternatively if the filters are blocked or need cleaning the unit will display this on the control panel.
Can this unit be run on solar power?
Yes, but the power consumption is so low that it is not really economic to do so.
Can this unit be run by a DC power supply?
Yes, but even though the fans are brushless DC motors the PCB must be supplied with
220/1/50Hz power. This can be achieved through a pure sign wave inverter 12v DC to
220v AC. This type of system is used on some large yachts where the ERV is primarily used
to supply fresh air to cabins and prevent condensation.
What size is the unit?
The average physical dimensions of a typical unit is 700mm wide X 550mm deep X 900mm high however to allow comfortable space for installation of ductwork, servicing and changing filters the minimum space you should allow for installation is 1800mm wide X 1200mm deep X 1200mm high.
Do I have to use rigid ducting or can I use flexible ducting?
Our systems are designed to use an aluminium polyester composite flexible duct. Although, the ducts look the same the supply ducting is acoustically treated to control airborne noise at termination. The ducts are specially manufactured and are fire rated to the highest standard Euroclass Bs-1, d0.
Aperture Web Design