T7 Design Universal Lightweight Heater (12 V) For Competition | Kit Car | Camper

    The T7Design 3.5kW Lightweight Heater provides compact, high output cabin heating and windscreen defrosting in space restricted installations. It achieves this using a 3.5kW copper and brass heater core with high flow tube design, high fin density and ultra-thin wall construction, combined with a lightweight single speed axial fan and 4 ducted outlet positions.

    The following features explain how this heater delivers effective heat output and flexible installation options:

    • 3.5kW Copper & Brass Heater Core: A specially engineered copper and brass matrix with high flow tube layout, high fin density and ultra-thin wall tubes maximises thermal transfer from the coolant circuit into the airflow, enabling you to generate strong heat output from a compact unit and maintain clear visibility and cabin warmth in demanding conditions.
    • High Flow Core Design: The internal coolant passages are designed to promote efficient coolant circulation across the full surface area of the core, allowing you to extract consistent heat energy from the engine cooling system and achieve stable, reliable heating performance during continuous use.
    • Ultra-Thin Wall Tube Construction: The thin wall tube structure increases the effective heat exchange surface area without increasing overall size, enabling you to install the heater in tight spaces while still achieving effective defrosting and interior heating.
    • Single Speed Axial Fan Assembly: The lightweight axial fan draws air directly through the heater matrix and expels it through the outlet nozzles, reducing electrical load by using approximately 25% of the power of traditional centrifugal blowers and keeping overall system weight at least 50% lower for efficient operation.
    • Dual Adjustable Lower Side Vents: Two integrated lower vents can be manually adjusted to direct heated air into the footwells, allowing you to target lower cabin areas and improve comfort during cold weather driving.
    • Configurable Upper Outlet Positions: Up to three outlet positions are available in the upper section of the enclosure, with outlet spigots supplied loose for you to rivet in place where required, giving you control over duct routing and airflow direction within your installation layout.
    • 51mm Outlet Diameter: Four 51mm (2") outlet diameters allow you to  duct hot air where required, ensuring proper airflow distribution and straightforward integration into your existing ventilation system.
    • Lightweight Compact Motorsport-Focused Design: The low mass construction combined with a compact enclosure and 3.5kW high efficiency heater core allows you to install effective cabin heating and windscreen defrosting in vehicles where packaging space and weight distribution are tightly controlled, making it suitable for competition cars, kit cars, custom builds and heater upgrades in classic vehicles while maintaining practical integration within confined interiors.

    You gain a compact 3.5kW heating solution that supports reliable windscreen demisting and controlled cabin airflow through ducted outlets. The lightweight axial fan and efficient heater core design help you manage electrical load and available space within your vehicle. Adding this heater to your setup provides a practical and well-engineered solution for maintaining visibility and cabin comfort in a wide range of installations.

    13.09.2026, 10:08:16

    Demon Tweeks was established in 1971 to service the needs of the motorsport competitor and our principals of offering top products, quality, service and rapid availability are as important to us today as they were in the very beginning. We are leaders in the supply of race wear, competition and road tuning parts for cars and bikes. Within a staff totalling over 140 is a dedicated sales team servicing upwards of 3000 telephone and online enquiries received every day from the UK and the rest of the world.

    Our impressive 140,000 sq.ft. Superstore and warehousing facility in Wrexham, North Wales allows us to carry around £7 million worth of stock at all times, over 256,000 items – more than any competitor. Our rapid despatch and no quibble money back guarantee are here to give you the customer real confidence when ordering – you can count on us!

    UK DELIVERIES
    All items for sale in our eBay store are held in stock, most being offered with FREE UK MAINLAND DELIVERY (Northern Ireland, Scottish Highlands & Islands, Isle Of Man, Isle Of Scilly, Jersey and Guernsey are not eligible for free delivery unless the item can be sent in the post). If you choose the free delivery, the item will be sent via the most cost effective means possible, i.e. Parcelforce courier or 2nd class post (you can see which in the “Postage, returns and payments” tab). Please note: We are advised by Royal Mail that items sent 2nd class post can take up to a maximum of 14 working days to be delivered.

    OVERSEAS DELIVERIES
    Using eBay’s Global Shipping Program we ship to over 100 countries worldwide — and counting! When you view the item, you’ll see the item price plus estimated shipping and import charges. Once you purchase the item, the final charges appear at checkout. That means no additional charges or surprises when your item arrives. If your parcel is lost or damaged along the way, the GSP protections and policies will cover you.

    CAN I CHANGE MY ADDRESS ONCE I'VE PLACED MY ORDER?
    Please note, we run an automated system on eBay and the address details that come through to our system from eBay are the details you input at the checkout page and this is the address that we have to ship the order to.

    I'VE ADDED A NOTE TO MY ORDER, CAN YOU VIEW IT?
    Not always. As above, because of the automated system we operate and the sheer volume of orders we get, we CANNOT guarantee that we will see any eBay notes that you add to your purchase. If it is something vital to your order, please contact us via the eBay messaging system before purchasing.

    RETURNS
    Goods deemed unsuitable or not required may be returned via eBay for a refund if they are returned to us within a 30 day period from date of original order, subject to the following and depending on reason.

    • The cost of postage and packaging to return the item to us is paid by you, the customer.
    • Items are to be returned unused and returned in their original condition & packaging.

    IMPORTANT
    All returns for items purchased via our eBay store need to be done via your purchase history within eBay by selecting the item/s you wish to return. Click on the item and then more options, request a return choosing the correct reason and we will respond and issue you a returns authorisation number and details to do so.

    We cannot accept responsibility for returned parcels which are undelivered or damaged in transit back to us. Please retain your proof of postage etc.. as you may require it in the event of a claim with your carrier.

    The easiest way to contact us is via the eBay message system.

    Business Hours:
    Monday - Friday: 8.30am - 5.00pm
    Saturday & Sunday: CLOSED
    BANK HOLIDAYS: CLOSED

    * PLEASE NOTE: Messages sent outside the working hours will be answered as quickly as possible during the next working day. Also, during periods of high demand, there may be additional delays in us responding.