House Energy Loss
LETTER BOX ADDS TO DOOR MISERY
FACT
The letter box security drawback is coupled with a significant loss of house heat and increased CO2 emissions from buildings into the atmosphere.
You have spent £1,500 - £5,000 plus (typical installation costs) for fitting an efficient and economical boiler, spent thousands of pounds on replacement windows, loft and cavity wall insulation but your energy bills are still running high! What can be the problem?
Before paying for big energy-saving technology it is important that simple and cost-effective steps are taken to increase the energy efficiency of the property.
The first place to look is at your exterior door(s). Gaps around doors, including the letter box and the keyholes, are the most common sources of draughts. A letterplate flap does not seal very well against its frame. It is usually quoted that these gaps are responsible for 15-20% of house energy loss.
But with the letter box it is not just the draughts. What is often overlooked is that the letterplate is often stuck open for hours by mail items.
Letterplates come in all sizes, but they are mostly small for security reasons. This creates obstruction to mail delivery and functionality. For example, you can't drop keys through a small letterplate. If a letterplate has brush strips or a secondary flap fitted for draught proofing, this too creates obstruction to mail delivery.
Our postmen are used to struggling with small size letter boxes, over-tight letterplates, brush seals and secondary flaps. Therefore, they instinctively tend to roll up or fold the mail items as a tube before pushing them through. Then mail items remain in the letterplate and keep the flap open, often for hours. A tight flap, secondary flap or draught excluder with brush strips do not work in this situation.
The situation is exacerbated with many random people involved in the delivery of junk mail, free newspapers, leaflets, etc., who do not care much to push their items fully through and close the flap.
A quote from the web:
'Yesterday I posted a folded A4 page through a dozen neighbours' letterboxes. Most of these provided an assault course of multiple brushes and spring-loaded flaps. Generally I could only post the letter by poking my fingers all the way in, always wondering whether they would come out uninjured. Aaargh! It must be hell for the posties, couriers and leafleters.'
With the average temperature difference in winter in the UK 16°C, average wind speed 5m/s and the stack effect the open letterplate works as an extraction fan. Heat moves from hotter areas to cooler areas. The common practice is not to close internal doors, so the heat loss from the house entrance hall area will extend into all house.
The heat of a house or a room quickly disappears out into a colder space and room temperature can easily drop.
When you have loss of heat through your letter box, it results in dramatic efficiency losses for your property heating in cold seasons. As a result, your energy bills go up and the production of wasted power for heating your home generates enhanced greenhouse gas emissions into the atmosphere, which contribute to global warming and climate change.
A quote from the web:
'Ha! Just had the classic experience of returning home to find the hallway like a fridge. Culprit? The new telephone directory stuck in the door creating about 16 sq inches of hole to the outside -1ºC.
Well, look at it this way: The clown who shoved it into the door saved a hell of a lot energy by not exerting him or herself and pushing it all the way through. It needed about a whisper of push to clear the last offending 1/4".'
Calculating cost of heat loss
The actual impact of loss of house heat through the letter box on the energy bills and CO2 emissions is difficult to quantify precisely as it depends on a large number of factors and will vary depending on your circumstances, such as the size of your home, indoor and outdoor temperature differences, size of your letterplate and lengths of periods when it stays open during the day and at night (at night there is a bigger temperature difference between the inside and the outside), average seasonal wind speed, length of the heating season, relative humidity, whether gas or electricity is used for heating, etc.
However, like with other energy-saving measures, we can get a conservative estimate assuming the average reduction in room temperature by 1°C only.
According to The Energy Saving Trust, reduction in room temperature by only 1°C can increase the heating bills by up to 10%. It is known that around 60% of the energy use in an average home is for space heating. With the January 2011 natural gas and electricity prices this would typically cost around £75 per year* and result in extra 300kg of CO2 per year.
* Based on 10% increase in energy used for space heating, which is 60% of £1,249 fuel bill. Bill size is based on a medium user using 3,300 kWh of electricity and 20,500 kWh of gas on a standard dual fuel plan paying on receipt of bill averaged across all regions.
Imagine how much the heating bills can go up when with freezing outdoor weather room temperature is reduced by more than 1°C.
This undermines costly investments in energy efficiency and spoils the chances of achieving the UK's 2050 target of reducing CO2 emissions from all dwellings by an average of 80%. Loss of house heat through the letter box is the biggest unresolved challenge facing most properties and the energy products installers today.
Using advanced energy-saving technologies to compensate for poor levels of insulation is an inappropriate trade-offs, which is discouraged by Building Regulations.
Insulate your letter box
All you need to stop the draughts, says the Energy Saving Trust, is to install a cheap, easy-to-fix brush or PVC seal on your exterior door and to cover the letter boxes too.
The question is: how do you cover the letter boxes?
You will find adverts selling an easy-to-fix letter box draught excluder with brush strips for placing over the letter box "to eliminate or reduce letter box draughts".
However, read this:
'Letter box draughts
Letter boxes are notorious for letting in a draught. One solution is to fit brush strip over the letter box. However, the downside is that these devices make it almost impossible to push newspapers and magazines fully through. This means that you'll probably arrive home from work to find that the newspaper will be rolled up and sticking out of the letterbox, and creating a worse draught than you would have had before the brush strip was fitted.'
It appears that these cheap (and some not so cheap) products work to reduce draughts only when the letterplate flap is closed - this is when there is not much draughts anyway. However, they simply do not work, as soon as a newspaper or mail is left in the slot. The brushes get deformed and let the house heat out. The temperature and air pressure differences between inside and outside sucks cold air into the building or forces warm air to leak outside.
Sealing an open letterplate from the weather without disruption to mail delivery is more demanding than it may seem. Products that do not insulate the letter box when the letterplate flap is open are useless and even harmful because they give way for more letter box draughts, house energy loss and increased CO2 emissions contributing to the greenhouse effect and climate change.
External doors with these products fitted provide less energy efficient options and are failing the current standards and regulations.
Millions of UK homes waste money on the energy bills because of the unprotected letter box. With the swingeing cuts outlined in the new budget and energy prices race, there has simply never been a better time to make efficiencies to your household budget.
It is logical to start with those technologies that are most cost-effective. Bring down your energy bills now by fitting IdealGuard™.